yyyyyssssyyyy yyyyssssyyyy yyyy yyyy |lS$$ yy $$$$ """" yy lS$$ S$$$ S$$$$$ $$$$$ S$$$ssssyyyy :|lS$ ""yyyyy yyyyssss|lS$ lS$$ lS$$ yy$$$$$ lS$$ yy lS$$ :||lS$$ $$$$$ :|lS yy :|lS |lS$ |lS$ $$ yyyy |lS$ $$ |lS$ :::|l ,$$$$$ ::|l $$ ::|l :|lS :|lS $$ :|lS :|lS $$ :|lS ::::| $$$$$$ :::| $$ :::| ::|l ::|l $$ ::|l ::|l $$ ::|l .:::: ....... .:::....:::: .::| ..:|....:::| .::| .. .::| ========================================================= F41th 14. May 2001. http://www.f41th.com. - D4RKCYDE - ========================================================= . : | +----> Message of the 0day hybrid +----> Mailbag various +----> Digital Multiplexing System janus +----> Meridian 1 PBX Admin: Part II Sneeka +----> Telewest VoIP re-load +----> Modem Brown-Box phractal +----> Time-Division Multiplexing foneman +----> UK Trunking Network Primer hybrid | : . . : | +--> Message of the 0day <--+ | : +--> hybrid The last f41th (f41th 13) was released in June 2000.. thats nearly a whole year ago now.. Why has everything been so idle? --dont ask me, maybee its somthing to do with lack of interest in phones and/or this mag. Some people sent me some highly crap "articles" for the zine, (probably over 15 of them), however, the ^M's and bad formating from lame cut and paste techniqs annoyed me, so I have left them out. I do not see the point in publishing somthing in this zine if it was directly cut'n'pasted from a reference guide, and especially if it was formated in windows.. When D4RKCYDE first started f41th, we recieved some good articles from people... stop sending shit, we have plently of docs allready, we dont need your cut'n'pasted windows pdf shit. -hybrid . : | +--> Mailbag <--+ | : +--> *@f41th.com Date: Wed, 24 Jan 2001 13:20:18 -0000 From: sue denim <@hotmail.com> To: hybrid@f41th.com Subject: request for help! whatsup? --> WAAAAAAAZZZZUUUUUUUUPPPPPP wasn't sure who to write to about this; basically i'm a hacker/phreaker newbie; looking for some info on:- manipulating an ericsson T28s? hiding my user identity/ making free calls? --> nice phone. what modern PAYT mobile is easiest to manipulate, and cheap to obtain? cracking email passwords??! --> people send you passwds in their emails? how can access the software on a simcard and change it? im using netscape 4.0, what kind of 'mischeif' can i get up to? --> wtf are you talking about?? basically i'm a complete newbie in modern computer software, but keen to learn unix/linux? whats a good starting point? --> http://linux.org | .com what can i do from a public shared machine? i'd love to hack/crack the fuck out of it!! --> yeah, you do that.. can i hack/crack from a laptop using a cellphone? --> yes send me some info; i'd be stoked and super grateful!! cheers. Date: Sat, 10 Feb 2001 11:11:14 -0700 From: no no <@hotmail.com> To: hybrid@f41th.com Subject: hi i wanna..... Hi i wanna join the uk phreak scene, i was wondering if u could maybe "mentor" me in my quest for ultimate knowledge :)If u are in any sort of phreak/hack team then maybe u could introduce me to a few people and my learning would come along a lot quicker, Thanks for yur time in writing those texts.. Da_0ne --> i am not in the uk phreak scene, the uk scene + D4RKCYDE are seperate --> things.. if you want to join the "scene" read alt.ph.uk, its elite, --> you will lean many things there. if you are looking to be a phreak, --> just stay away from the "scene" its pants, you'll realise that after --> a while... do your own thing.. come talk in #darkcyde efnet if you --> want to meet other ppl. Date: 14 Feb 2001 14:51:51 -0000 From: nasir xyz <@rediffmail.com> To: hybrid@f41th.com Subject: outgoing calls Dear friend, I found yr articles highly intersting I from country India . I know that you people can help me fooling my exchange . PLs tell me how can i make free outgoing call telephone calls from my home telephone(for example my exchange think tha my telephone is still ringing and i am not connected to the dail number) ,Is it possible or not, Can i do it by changing polarity with the help of diodes or Any other way. Thanks in advance/ Nasirxyz --> hmm, interesting idea about tricking the exchange into thinking the dialed number is --> still ringing.. i dont know how to do this though, probably not even possible depending --> on the types of exhanges involved.. if you exchange is digital, i suspect that this is --> impossible because of signalling reasons... dont' know though, might be worth looking into. Date: Wed, 14 Feb 2001 16:17:59 -0500 From: joel <@home.com> To: hybrid@f41th.com Subject: hey hey there .you wouldn't happen to know of any phoe number tracing software. i have a small company and we get all kinds of prank calls. I got caller id and they just come up no info. They are probley hitting *67 like i do. Any help you could give would be great.... JD --> Hi there. Thanks for the info. I called the telco Co. and they are coming out next week to trap my line they said. Hopefully that helps. A few pranks were funny but the way they talk to the women that work here is uncalled for. Thanks again very much...Jd --> NP! Date: Sat, 17 Feb 2001 02:27:01 +0800 From: nein wan wan <@spam.org> To: hybrid@f41th.com Subject: Your publication I am interested in getting involved with your publication. Is this possible? You have probably talked to me before, as I've been around for a while. I'm an old fart wanting to get back into the scene. Your response would be greatly appreciated. -- nein -- --> sure, cometo #darkcyde on efnet and we'll talk about it. Date: Thu, 22 Feb 2001 10:39:11 -0800 (PST) From: John Wilson <@yahoo.com> To: hybrid@f41th.com Subject: Dear Hybrid: Hi, My Name Is John.I'm 17 Years Old And I Have Been Reading Your Articles About The "Underground Telecommunications". If You Would Please Fill Me In A Little More About This Subject.I'm Highly Intrested And I Got All The Time It Takes. The So Called "Government" Is Hideing Something From You And I And I Will Die To Find Out What That Is. I Would Appreciate You Mailing Me Back. Thank You Vey Much.. Sincerely, John --> http://hybrid.dtmf.org .. Date: Thu, 22 Feb 2001 15:22:03 -0600 (CST) From: @hushmail.com To: hybrid@f41th.com Subject: info Was wondering if you guys had an updated list on hackers under investigation. The fbi has been investigating my group and they just took some of my computer shit, so we kinda want to know heh --> what kind of shit did they take? yea...my dedicated server. --> D4RKCYDE has been idle for a while now, we havn't done anything to draw --> much attention of that type to us.. I remember when we where "under investigation" --> from the FBI (from antionline), probably bullshit though, never paid attention to --> that.. Date: Thu, 22 Feb 2001 21:24:31 -0000 From: A Osman <@btinternet.com> To: hybrid@f41th.com Subject: Pay as you go Hi I hope you and your friends could shed some light on this situation. I have been collecting used One2One pay as you go vouchers in a vain attempt to try and crack the code that they use. Dont know if you deal with mobiles but any help would be great. Wokky --> One2One probably have some extreamly random procedure for generating the --> codes, i wouldnt waste my time if i where you.. Date: 7 Mar 2001 15:19:17 -0800 From: Atlantic Lab <@techemail.com> To: hybrid@f41th.com Subject: Necromancy! I'm just a small potato in a large potato field but I want to grow. How would I do so! Where would I start? --> you got me.. Date: 8 Mar 2001 13:55:35 -0800 From: Atlantic Lab <@techemail.com> To: hybrid@f41th.com Subject: more magic please! The Bode' Darma sat in front of a wall in a cave for 9 years. When he felt that he was finished, he left and the world became a richer place because of his teachings, Men found a harmony and richness within themselves through physical and spiritual expression! --> please stop emailing me, you are scary. Date: Thu, 8 Mar 2001 22:41:24 -0800 (PST) From: dogg <@yahoo.com> To: hybrid@f41th.com Subject: information request I'm not really sure I have the right email address, but i was wondering...is there a way to actually find a persons email code with a cd program. please respond if you have any information on any related topics. thanks --> email code? Date: Fri, 09 Mar 2001 09:18:58 -0000 From: Sharpish Me <@hotmail.com> To: hybrid@f41th.com Subject: F41th mirror... I read the f41th txt's at college, found them interesting, so I mirror'd them on my w/s. I'm a newb to all this, I just find it interesting... the link: http://www.simpletown.com/sharpish/f41th/f41thmenu.htm There ya go. Sharpish ++++++++++++++++++ "Wake me when the future happens..." ++++++++++++++++++ --> thanks, i'll put it on the site links if you update it. Date: 10 Mar 2001 10:56:09 -0800 From: Atlantic Lab <@techemail.com> To: hybrid@f41th.com Subject: last magic! It seems to me that whatever understanding we share of each other is going to be our personal undoing! I assure you I'm just another individual with tremendous interest in what you have written, not who you are! There is a project that I'm currently working on that will allow me to find data that doesn't want to be found! All I ask is possibly some feedback! Ideas! Input! This is all!!! If you choose not to correspond I will understand, and discontinue these transmissions! Thank You :) --> PLEASE STOP EMAILING ME!$£@$! Date: Sat, 10 Mar 2001 19:13:50 +0000 From: @one2one.net To: hybrid@F41th.com Subject: Phone Phreaking ! Hi, Is it possible to obtain free phone calls through phone phreaking ? Thanks Chris --> yeah i guess so. Date: Sun, 18 Mar 2001 16:54:20 +0000 (GMT) From: "[iso-8859-1] bob bob" <@yahoo.co.uk> To: hybrid@dtmf.org hi, i am a newbie phreak(thought it best to say before i carry on and not be a bigger lamer by pretending i m eliet or anything....) i have done a few things however, i got in to some blokes vmb,listened to his messages and changed his OGM. pretty small fry realy but good for a start. anyways, the problem i have is barred numbers on payphones(thats what ive done everything through up till now) i can only dial 0800 no's, i wanted to know any methods of getting around this, and also how numbers are barred? and ways of baring/unbarring them. some nice posibilities there... so anyway, keep up the good work on the d4rkcyde and help me on the way to leaving lamerdom, from pa_p_ercllps --> you changed someones OGM?? why did you do that yo? train --> yourself to prowl in the shadows of the trunk, its the --> way of the ninja. Date: Mon, 26 Mar 2001 11:07:29 +0500 From: BEE ANN <@hotmail.com> To: hybrid@f41th.com Subject: C L I Hi, I read your articals, I am really inpired, I need your help in regard to stop my out going CLI, I live in Pakistan, and out PTT dose not provide such services like CLI with held or CLIR can you help me by telling me simple methods by using my pstn phone and stop my out-going CLI, as a metter of fact we know that some organisation have the ANI, but I want this for my personal use, our PTT has two swithing systems 1) Alcatel 2) Siemens. Moreover, If you can help me by telling me the simple procedure to stop the out going CLI by using my GSM 900 Mhz phone , the service provider of which use the Motorlla GSM switching systems. I am dyeing to read your positive reply. Thanking you in advance, Bee --> i'll look into it, i dont have much info on pakistan. Date: Tue, 27 Mar 2001 14:12:24 +0200 From: Nirmal D Morjaria <@lycos.com> To: hybrid@b4b0.org Subject: (No Subject) What is the purpose of these telephone numbers I have found on the internet. In this text file are they to make free phone calls?? --> no dude, they are scans.. either hand-scans (looking for interesting shit) or --> carrier scans (looking for modem carriers) Date: Mon, 2 Apr 2001 13:49:15 -0700 From: <@msn.com> To: hybrid@f41th.com Subject: HELP PLEASE HELP ME! I WANT TO KNOW IF MY GIRL IS CHEATING ON ME ,WOULD YOU BE ABLE TO TELL ME HOW TO HACK HER VOICEMAIL? --> DAMN$! its ok, sorry, i'll leave her alone, she told me she was single. Date: Wed, 4 Apr 2001 04:57:04 EDT From: @cs.com To: hybrid@f41th.com Subject: hey about your zine hey I was wonderin if your guys magazine is actually published or if its electronic, if its published is there anyway i can get a subscription in the US? I hope so it sounds really bad ass, i just wanted to ask and pay my respects to you guys so i hopefully will talk to one of you later, please email me with an answer. SiruX Of The Dark Alliance --> we have been thinking about publishing f41th as hard copy for a while now.. --> although we cannot find a printer, let alone somehwere to distribute.. --> maybee if people start sending good enough articles, we'll start printing.. --> for thew time being it will reamin in digital format. Date: Sat, 7 Apr 2001 00:40:38 EDT From: @cs.com To: hybrid@f41th.com Subject: Re: about your zine cool, thank you for actually returning the email, the underrgound needs more allies like you guys, aieght, well if you guys are excepting any articles or anything like that reply to me, and if you want ill write for ya, aieght, see ya! SiRuX --> werd dude, keep it real. Date: Wed, 18 Apr 2001 02:16:12 +0100 (BST) From: "[iso-8859-1] Martin Jones" <@yahoo.co.uk> To: hybrid@f41th.com Whosoever used the w32.baftrans.13312@mm virus and without due reason deleted the Yahoo account of a certain bluegrass playing duo is hereby given notice that they are on Doctor Zargs target list and will soon be suffering the retribution of the Fr33n3t 0rg. Be aware: hacking is a noble and artistic past time when directed against corporate entities and even personal webpresences but when exacted in a mischievous manner, resulting in destructive activity against independent entities it is considered an act of war. As a result of this act the 4th & 5th echelons of Albion Net Venturers are in Antagonist D mode. You script kiddies can do no harm to the Fr33', but many rising innocents are vulnerable and do not deserve your ignorant vandalism. Be aware we actively encourage and continuously monitor anarchical activity across the web but cannot condone desecration of the innocents. I am sending this from my personal address as a mark of my sincere wish to communicate my honest feelings on this matter and do so in good faith without blame against you or your community per say, but please understand that this recent abuse has resulted in a fully negative reaction fom the Freenet tech commune. Long live the new flesh. --> i have the fear. Date: Fri, 20 Apr 2001 12:58:59 -0700 (PDT) From: Webmaster <@b-w-d.net> To: hybrid@f41th.com Subject: Call-Waiting4free (BT got a ittle problem) #################################### ## Call-Waiting (Why pay for it?) ## #################################### Im quite new to phreaking, but ive found an exploit in the BT system allowing ANYONE to get call-waiting on their line, free. Its not the complete service (as you cant flick between calls with the BT menu) but you can still keep a call on hold and phone another number, the return to the original person. Hey, u may think call waitin is crap, but it can be usefull, trust me =] What you need: =============== 1. Quite an old phone 2. This text Note: the phone MUST be able to use pulse dialing...and directly! Preperation: ============== To make sure your phone will let you do this, pick up the phone and hold down the 1 button, if it sends out a continuous pulse, then you can do it, if it sends out seperate pulses, then ur fuckd. :P [for all u simple ppl, what i mean is, when u press down the button, if the sound coming from your phone is just a continueous sound, then its ok, otherwise, if its like, click-click-click-click, your fuckd] What ya do =========== 1. pick up the phone and call someone(the person your gonna put on hold, person 1). 2. Check your phone is set to pulse (if its capable of tone aswell). 3. Hold down the 1 button untill you hear a blank tone. 4. Make your next call (person 2). 5. Put down the phone when youve finished talking to person 2. # The phone will now ring asif you askd a number to call back when its no longer busy # 6. Pick up the phone and your back with person 1. 7. Hang up as per usual. The-Finger@BT.com ================== hey, have u ever wonderd why u sometimes get rung back by people? well, thats coz you accidentaly hit the receiver long enough to send this pulse down the line. BT's FAULT! yeah, BT does know about this, but its not fixed yet, and it usually only works from the person who called, but sometimes it works for both sides. ############################################## Credz go to me (.-=LeGiOn=-.) Vir0n (4 bein around 2 help) Enclave-Guardian (for my big phone bill) Every1-els@Brotherhood of Enclave ############################################## enclave-hackers.com www.b-w-d.co.uk/hack/ ############################################## Contact me at @b-w-d.net ... if ya want proof of this being my work, i got the document from BT about it, and it will be e-maild/snailmaild on request. . : | +--> Digital Multiplexing System <--+ | : +--> janus Digital Multiplexing System =========================== --This file will attempt to explain the DMS (Digital Multiplexing System). Think of this file as more of a compilation of the material I have read, rather than something I authored completely from scratch. Special thanks to Control-C for most of the information found here. -DMS ==== DMS was/is made by Northern Telecom. It was first introduced in 1979. To date, DMS has been able to interface with such switches as ESS #1-4, Xbar, TSPS, and EAX. The DMS switch itself is physically smaller than a Xbar switch, and usually smaller than most AXE switches. This is because the DMS switch is more spread out, as opposed to other types of switches which are all located in one switch house. The use of remote modules give the CO more space to install a Line Concentrating Module (LCM) or Main Distribution Frame (MDF). Many versions of DMS exist. DMS versions and systems are as follows: 1) DMS-10 - =========== a C5 switch which can be used with up to 10,800 lines. Designed for rural areas and large businesses. Almost always connected with a larger DMS-100 or -100/200 switch. 2) DMS-100 - ============ a C5 local office able to be used with 1,000 to 100,000 lines. Very widely used today to handle residential areas' phone lines. A DMS-100 local office can also be adapted to Equal Access End Office (EAEO) 3) DMS-200 - ============ can be used with up to 60,000 trunks. Can also serve a AT (Access Tandem) function. The Auxiliary Operator Services System (AOSS) is a part of DMS-200 that controls Operater-assisted calls, such as Directory Assistance. AOSS is made possible by Traffic Operator Position System (TOPS) and Operator Centralization (OC). These 2 functions allow transfer operator services from other DMS-200 toll centers. 4) DMS 100/200 - ================ Uses functions such as the toll and local systems mentioned above, but also includes the EAEO/AT combination. Can handle either 100,000 lines or 60,000 trunks. Used instead of using -100 and -200 seperately. 5) DMS-250 - ============ Not very widely used. Used in association with specialized common carriers that need tandem switching. 6) DMS-300 - ============ Designed for international use. The number of DMS-300 switches that are used is in the single digits. 7) Remote Switching Center (RSC) - ================================== Used instead of DMS-100, it has the ability to switch up to 5,760 lines. 8) Remote Line Concentrating Module (RLCM) - ============================================ Able to switch up to 640 lines. Can be used with RSC or DMS-100 with assistance from the Line Concentrator Module (LCM). 9) Outside Plant Module (OPM) - =============================== Able to switch up to 640 lines. Can also be used in association with RSC or DMS-100. 10) Subscriber Carrier Module (SCM or SCM-100) - ================================================ -a) Subscriber Carrier Module (Rural (SCM-100R)) - Eliminates the CO Central Control Terminal (CCT) by being integrated with a DMS-100 switch. -b) Subscriber Carrier Module SLC-96 (SCM-100S) - gives a direct link between DMS-100 and SLC-96 loop carriers. -c) Subscriber Carrier Module Urban (SCM-100U) - Used to interact with DMS-1 Urban (DMS version specialized for use in urban areas.) 11) DMS-Mobile Telephone Exhange (DMS-MTX) - ============================================ A special type of DMS-100 that is used with Cellular switching. is used with Cellular switching. It can serve up to 50,000 people in up to 50 cells. 12) Supernode ============= -a) DMS-Supernode - Revision of the DMS-100 that supports faster processing. -b) DMS-Supernode SE - same as above, except in a reduced physical size, and uses the Link Peripheral Processor (LPP). Important Features of DMS-100: ============================== 1) Automatic Route Selection - automatically detects the best trunk for routing toll and LD calls. 2) Station Message Detail Recording - an enhanced call logging system,keeps track of times, dates, duration, etc. 3) Direct Inward System Access (DISA) - allows maintenance and administration from remote terminals. Operator Features included with DMS-200 and -100/200: ===================================================== 1) Traffic Operator Position System (TOPS) - gives certain functions to handle incoming and outgoing calls. 2) Operator Centralization (OC) - Lets an operator interface with the switch equipment itself. Allows calls to be routed from a remote DMS switch to a host. DMS is divided into 4 areas that each handle special operations: ================================================================ 1) Central Control Complex (CCC) - Controls the functions that are used in the other 3 areas. The CCC contains 4 units: -a) Central Processing Unit: Each DMS switch contains 2 CPUs. The CPUs have access to memory banks where stored programs and network data are located. Consider the CPUs the "engines" of the switch. They process all incoming data from outside lines. -b) Program Store Memory Module: Associated with one CPU to contain the program instructions needed to run programs on the switch. The second PS contains duplicate instructions. -c) Data Store Memory Module: Contains information such as customer information and office data. The second DS is a duplicate that is used with the second CPU. -d) Central Message Controller: Controls the messages between the other areas of the CCC and the Network Message Controller (NMC) in the various Network Modules or the I/O controller. Both CPUs have access to the CMC. 2) Network (NET) - Network Modules handle the vocal aspect between the Peripheral Modules and the Central Control Complex (CCC). 3) Peripheral Modules (PM) - Interface between analog trunks, subscriber lines, and digital carrier spans (DS-1). Responsible for creating dialtones, sending/receiving signalling, and checking the network. Before 1984, the following types of PMs existed: ================================================ -a) Trunk Module - Changes speech into digital format to be sent through the line. The TM also handles MF tones, test circuit announcement trunks, etc. -b) Digital Carrier Module - gives a digital interface between the DMS switch and the DS-1 digital carrier. The DS-1 signal consists of 24 voice channels. -c) Line Module - gives an interface for a maximum of 640 analog lines and condenses the voice and signaling into two, three, or four DS-30, 32-channel speech links. -d) Remote Line Module - same as above, except it controls the DMS switch remotely. Can be used up to 150 miles away. Since 1984, 10 more types were added: ===================================== -a) Digital Trunk Controller - Interfaces up to 20 DS-1 lines, then sends the DS-1 lines to the network. -b) Line Group Controller - Can interface up to 20 DS-30 lines, and can serve RSCs, RLCMs, or OPMs. -c) Line Trunk Controller - has the ability to give interfaces to a maximum of 20 outside ports from DS-30A speech links or DS-1 links to 16 network side DS-30 speech links. -d) Line Concentrating Module - An expanded version of the LTC, it can serve up to 640 subscriber lines interfaced with 2-6 DS-30 speech links. -e) Remote Switching Center - interfaces subscriber lines at a remote location to a DMS-100 host. The RSC consists of the Line Concentrator Module, Remote Cluster Controller, Remote Trunking, Remote-off-Remote, and Emergency Stand-alone. -f) Remote Line Concentrating Module - an LCM used from a remote location from the DMS-100 host. Can handle up to 640 lines, sometimes used as replacement for PBXs. -g) Outside Plant Module - Outside plant remote unit. Handles 640 lines over 6 DS-1 Links. -h) Subscriber Carrier Module - Remote interface for remote concentrators. -i) SCM-100R - Can interface up to five DMS-1R Terminals. Each terminal can handle up to 256 lines. -j) SCM-100U - Can interface up to three DMS-1 Urban RTs. Each RT can interface up to 576 POTS or special service lines. 4) Maintenance and Adminstration - ================================== DMS provides different ways to maintain and administrate the network. M&A is divided into 4 major groups: -a) Administrative: Provides for the interrogation, collection and modification of data. -b) Internal Maintenance: Includes all DMS hardware (to the MDF) and software. -c) External Maintenance: Includes circuits on the transmission facility. -d) Reporting: Include I/O facilities and the alarm system. Common Channel Interoffice Signalling (CCIS) uses a dedicated line to transmit data between offices, trunks, or trunk groups. CCIS-6 uses the International Consultative Committee on Telephone and Telegraph (CCITT) No. 6 international standard. CCIS-7 added the ability to use CCIS with almost all common DMS versions such as DMS-100, -200, -100/200, and -100/200 with TOPS. CCIS-6 uses 2 types of Serving Offices (SO): 1) CCIS-BS: =========== used for trunk signalling between COs. Transmits data such as numbers dialed, numbers dialed from, and other routing information. CCIS-BS put an end to Blue Boxing. 2) CCIS-DS: =========== enables the use of touch-tone menu administration, such as voicemail, calling card imput, and so forth. Access Tandems: =============== 1) Equal Access (EA) gives a connection between Local Access and Transport Areas (LATA). It provides such services as ANI, Automatic Message Accounting (AMA) for both originating and terminating calls, and operator service signalling. 2) Equal Office End Office (EAEO) gives a connection between interLATA carriers and international carriers' POP. 3) Access Tandem with Equal Access End Office gives a connection from a trunk tandem to ICs/INCs POP inside a LATA. It uses a two-stage "overlap output pulsing" method which makes dialing quicker and easier. The first stage identifies the INC dialed and picks a reliable outgoing trunk. A connection is established from the INC to the EAEO through the access tandem. The second stage processes ANI and makes a connection to the called number through your specific DMS switch type. 4) Access Tandem with a Non-Equal End Office uses Feature Group A, B, or C to connect to an IC/INC. It uses standard Central Automatic Message Accouting (CAMA) to palce a call through AT. Other services provided with DMS switches used in urban areas are as follows: 1) Auxiliary Operator Services System (AOSS) - ============================================== used primarily for directory assistance, and the intercept needs not included with TOPS. 2) Integrated Business Network (IBN) - ====================================== commercial concept designed for business to have a small, private PBX. IBN can be installed into a business to a Centrex Control Office or a Centrex Costumer Unit with minor hardware adjustments. Features of IBN include the ability to handle 30,000 lines, customer call records, centralized attendant maintenance, administration functions, and direct inward dialing. 3) Electronic Switched Network (ESN) - ====================================== designed to meet needs of multi-location complexes. Used with SL-1 or -100 Digital Business Communications Systems with networking features or a DMS-100 IBN host. 4) Specialized Common Carrier Service (SCCS) - ============================================== provides conversion of analog and digital signals. Must be used with older analog and digital signals. Must be used with older analog lines, sometimes also used with newer digital lines. DMS-MTX is a DMS switch used for switching radio and cellular signals. DMS switches provide 3 basic types of cell switching: 1) Stand-alone switching is used by a MTX which is interfaced with one or more C5 EOs with DID trunks. MTX is used with urban areas, MTXC ==== for suburban areas, and MTXM for rural areas. 2) Combined switching is the most cost-effective type of MTX and is easy to install. It can be incorporated into a DMS-100 switch and used with cellular software. 3) Remote switching is accomplished by the Remote Switching Center (RSC) alongside a Cell Site Controller (CSC). A Remote or Stand-alone switch hosts the remote switch. Remote switching is not used in urban areas. __________________ Suggested Reading: Understanding DMS; Control-C; 1987 (Most of my information came from here!) DMS Family of Digital Switching Systems; Erudite; ???? DMS-100; Jester Sluggo; ???? DMS-100 Family System; Northern Telecom; 1978 --Janus janusx0r@hotmail.com . : | +--> Meridian 1 PBX Admin: Part II <--+ | : +--> Sneeka Meridian 1 PBX Admin: Part II Typed up and slightly edited by Sneeka =-=-=-=-=-=-=-=-=-=-=-=-=-=-= (sneeka1@hotmail.com) Ok, here we go, the second part. If you read the first part you should know all about how the basic system operates and know how to move and change extensions etc. This part will concentrate on the various features you can apply to extensions along with guides for implementing them. Sneeka -------------------------------------------------------------------------------- FEATURE ACTIVATION CODES ======================== Introduction ------------ Features are activated and deactivated by keying codes into the telephone set and, in the case of digital sets, by pressing single keys for certain features. There are two methods of invoking features, namely Special Prefix (SPRE) code working and Flexible Feature Code (FFC) working. Flexible Feature Code (FFC) Working ----------------------------------- Flexible Feature Code working allows the sysadmin to assign their own codes to chosen features. This allows each Meridian 1 to be tailored to a logical pattern of codes to suit each company or to retain the same feature codes as those used on their previous telephone system. FFCs are set and printed through Program 57. The Option 11 default FFCs are given in the table below: Feature FFC ---------------------------------- Ring Again #31 Cancel Ring Again #32 Answer Call Pickup **0 Answer Group Pickup *00 Directed (DN) Pickup *09 Authorisation Code *21 Call Park #51 Retrieve Parked Call #52 Dial System Speed Call *3 Store Speed Call #33 Dial Speed Call #34 Call Forward all Calls #1 Hold (Permanent) #55 Store Number for Redial *24 Dial Stored Number Redial *25 Last Number Redial *44 Group Hunt Opt In #58 Group Hunt Opt Out #59 Automatic Set Relocation *90 Automatic Set Removal *92 Night Service Pickup *8 Remote Call Forward *56 Override *26 Charge Account #56 SPRE Code Working ----------------- This method of working is not very common. These codes are used by extension users without multi-frequency tone key phones. [ in other words, pulse dialling - Snk ] SPRE code working consist of two parts: SPRE code followed by FFC ========================= The SPRE code tells the system that a feature is about to be activated or deactivated and the FFC identifies the particular feature. The SPRE code can be changed to be any value (max. 4 digits) so long as it doesn't clash with the extension number range or access codes for routes. The Option 11 system default SPRE code is 12. The FFCs however cannot be changed. Common codes are below: Feature FFC ---------------------------------- Ring Again 1 Cancel Ring Again 2 Answer Call Pickup 3 Answer Group Pickup 94 Directed (DN) Pickup 95 Authorisation Code 6 Call Park 71 Retrieve Parked Call 72 Dial System Speed Call 73 Store Speed Call 75 Dial Speed Call 76 Call Forward all Calls 74 Hold (Permanent) 77 Store Number for Redial 78 Dial Stored Number Redial 79 Last Number Redial 89 Night Service Pickup 4 Charge Account 5 Automatic Set Relocation 81 Activating Features From Digital Sets ------------------------------------- With digital sets some features must be assigned to a programmable key whereas other features can be invoked either by dialling a feature code or be assigned to a key. The following features if used must be assigned to a programmable key for activation: o Call Forward All Calls o Ring Again o Stored Number Redial o Last Number Redial o Speed Call User and Controller o System Speed Call Controller o Six Party Conference o Call Transfer o Call Park (Activation) o Call Waiting The following features may be assigned to a key or invoked using the relevant feature code: o Call Park (retrieve) o System Speed Call User o Call Pickup o Charge Account Listing all the FFCs on the System ================================== You can print out the current code for all FFCs on the system using Program 57. >LD 57 REQ PRT TYPE FFC CUST 0 CODE ALL The system responds by printing all FFCs, and a typical printout is shown below. CUST 00 FFCT YES ASRC *90 AUTH *21 AWUA AWUD AWUV CDRC #56 CFWA #1 CFWD #1 CFWV COND CPAC #52 CPRK #51 C6DS DEAF DPVS ELKA ELKD PLDN 2000 USE GPHT LSNO 050 HTYP RRB CFWI NO MQUE 0 2000 | | | | HOLD #55 ICPA ICPD ICPO ICPP IMS MNTC *93 MTRC OVRD *26 PUDN *09 PUGR *00 PURN **0 RCFA *56 RCFD *57 RCFV RDLN *44 RDNE RDSN *25 RDST *24 RGAA #31 RGAD #32 RGAV RMST SCPC SPCC #33 SPCE #36 SPCU #34 TFAS *8 TRMD TRVS *95 USTA LILO NRDY GHTA #58 GHTD #59 SADS SAEN SALK SAUN EOVR AREM *92 ADMN *91 Listing a Particular FFC ======================== You can identify the code for a particular feature by using the Program 57. The following example shows how to print the FCC associated with the "Ring Again Activation (RGAA)" feature. >LD 57 REQ PRT TYPE FFC CUST 0 CODE RGAA The system responds with: CUST 00 FFCT YES RGAA #31 CODE {Hit Return here to get back to the REQ prompt} REQ END {Exit} Adding a New FFC ================ A code for any FFC can be added using Program 57. The following example shows a new "Ring Again Activation Code (RGAA)" of #66 being added. >LD 57 REQ CHG {Meaning 'Change' - used even if you're adding a new code} TYPE FFC CUST 0 FFCT CODE RGAA {The feature mnemonic} RGAA #66 {The code number} RGAA {Return through this if you don't want to define any more features} CODE {Return here too} REQ END {Exit} Deleting a FCC ============== Again, use Program 57 to delete an FFC. The following shows a "Ring Again Activation Code (RGAA)" of #31 being deleted: >LD 57 REQ OUT TYPE FFC CUST O ALL NO CODE RGAA RGAA #31 RGAA {Carriage Return to confirm the delete} CODE {Return to indicate no other features are to be deleted} REQ END {Exit} Changing a FFC ============== To change an FFC just delete the existing code and then add the new code. FEATURE PACKAGING ================= Introduction ------------ Most features are supplied as standard with the system. Optional feature groups can be bought for specific applications eg. Automatic Call Distribution (ACD). This section demonstrates how to list the features on a system and shows how to identify the software package containing any particular feature. Printing the Features that Exist on the System ============================================== You can list the features currently on the system by loading Program 22 and following the steps below. >LD 22 REQ PRT TYPE PKG {Meaning 'Packages'} The system responds by listing the mnemonic for all the feature packages installed on the system. OPTF CUST CDR CTY CLNK RAN TAD . . . SR AA HIST BARS NARS XPE XCT0 XCT1 NACD REQ END {Exit} FEATURE DESCRIPTIONS ==================== Autodial ======== Description ----------- The Autodial feature allows extension users with digital sets to store a telephone number under an "Autodial Key" and when desired make a call to that number by pressing the key. The sysadmin can restrict the length of number that an extension user can store under the key to one of the following 4, 8, 12, 16, 20 or 23. To store the number under an Autodial press the key, then key in the number and finally press the Autodial key again to save the number. To use the autodial key first press an idle DN key and then press the Autodial key. Implementation -------------- To configure this feature first identify the TN of the extension, the key to be used and then determine the maximum number of digits the extension user will be allowed to store. Then you can either input a stored number or leave it for the extension user to input from their telephone. Use Program 11 as follows: ITEM KEY xx ADL yy zzzzzzzz where xx = key number yy = maximum length of Autodial number zz = the digits to be dialled automatically (optional) Example ------- In this example the Autodial feature has been assigned to key 8 of a digital set located at TN 8 3. The user is allowed to store up to 16 digits and the number 908658081 is initially stored. >LD 11 REQ CHG TYPE 2616 TN 8 3 {Identify the TN} ECHG YES {Use EasyChange} ITEM KEY 8 ADL 16 908658081 {Allocate Autodial to key 8, limit the number of digits stored to 16 and store 908658081} ITEM {No more keys to configure so Return through this} REQ END {Exit} Automatic Answerback ==================== Description ----------- This feature is useful to anyone that requires complete hands free operation of their M2616 type set. When the feature is activated any incoming calls to that set will ring the phone once and then be automatically answered. Implementation -------------- This feature can be implemented in two ways. The first is by setting the Class of Service to AAA. This will cause every incoming call to ring the extension once and then be automatically answered. The second is to allocate the feature to a key. This allows the extension user to activate or deactivate the feature as desired. Example ------- In this example the Automatic Answerback feature has been assigned to key 8 of a digital set located at TN 8 3. >LD 11 REQ CHG TYPE 2616 TN 8 3 ECHG YES ITEM KEY 8 AAK KEY ITEM REQ END {Exit} Automatic Hold ============== Description ----------- This feature can only be assigned to digital sets. It allows users to place a call on hold without using the "Hold" key. For sets with multiple DNs the user can have two or more calls active at the same time and switch between the calls without placing the active call on hold. As the DN of a held call is pressed to retrieve that call the active call is automatically put on hold. Attempting to switch between DNs without this feature would cause the active call to be cut off. Implementation -------------- This feature is configured in the Class of Service in Program 11. Example ------- In this example the Automatic Hold feature has been assigned to a digital set located at TN 8 3. >LD 11 REQ CHG TYPE 2616 TN 8 3 ECHG YES ITEM CLS AHA ITEM REQ END {Exit} Authorisation Codes =================== Description ----------- This feature gives "authorised personnel" a mechanism to temporarily override the Call Restriction (barring) applicable to an extension thus allowing them to make a from normally barred extensions. Such an example might be a manager who is regularly called to other parts of the building. The manager need only dial the Authorisation Code FFC (*21 is the default) followed by their "Personal Identification Number (PIN)" and, when dial tone is returned, the number they require. This action will then override any barring for one call. Implementation -------------- Authorisation codes are added, changed, deleted and printed in Program 88. They are programmed in two parts. First to define the authorisation codes, and secondly to define the call restrictions applied to that code: a) Type AUB (Authorisation data block). This allows different combinations of Class of Service (COS), Trunk Group Access Rescriction (TGAR) and/or Network Class of Service (NCOS) to be defined. The different combinations of COS TGAR and NCOS are assigned to what is termed a classcode (CLAS). There can be a maximum of 116 (0 to 115) different CLAS on the system. AUB ---------------------------------- CLAS COS ---------------------------------- 0 UNR, TGAR=1 1 TLD, NCOS=2 2 UNR . . 115 UNR b) Type AUT (Authorisation code Entries). This is where the individual PIN numbers are defined. The Authorisation Code (CODE), or PIN, is assigned to a Classcode value (CLAS) which will determine any restriction, that will apply when the code is used. AUT --------------------- CODE CLAS --------------------- 2745 0 2632 1 9789 2 3428 1 6679 2 Example ------- In this example two new Authorisation Codes with unrestricted will be set up. First print the AUB to find a CLAS which has a COS = UNR (unrestricted). Then print the AUT to identify which CODEs (PINs) are already in use. Then create two new CODEs: >LD 88 REQ PRT TYPE AUB CUST 0 The system responds by printing the Authorisation Data Block. From this you can see that CLAS 1 has a COS of UNR. CUST 00 ALEN 04 ACDR YES RANR X AUTO NO CLAS COS TGAR NCOS CLAS COS TGAR NCOS CLAS COS TGAR NCOS --------------------- --------------------- --------------------- 000 TLD 01 07 001 UNR 00 00 002 TLD 00 02 003 UNR 00 00 004 UNR 00 00 005 UNR 00 00 006 UNR 00 00 007 UNR 00 00 008 UNR 00 00 009 UNR 00 00 010 UNR 00 00 011 UNR 00 00 012 UNR 00 00 013 UNR 00 00 014 UNR 00 00 . . . . . . . . . . . . 111 UNR 00 00 112 UNR 00 00 113 UNR 00 00 114 UNR 00 00 115 UNR 00 00 To find the authorisation codes are in use. REQ PRT TYPE AUT CUST 0 CODE The system responds with the list. CODE 1111 CLAS 001 CODE 1234 CLAS 000 Now two new codes can be set up, eg. 5218 and 2465. REQ NEW TYPE AUT CUST 0 CODE 5218 SARC {Return at this leaves the prompt at default. The default is NO to indicate that this code is not being used for the Schedule Access Restriction feature} CLAS 1 {To allocate code to CLAS 001} CODE 2465 {Repeat procedure to add code 2465} SARC CLAS 1 CODE REQ END {Exit} CALL FORWARDING =============== Introduction ============ On the Meridian system there are a number of features associated with call forwarding. This section will concentrate on the common ones: o Call Forward All Calls o Call Forward No Answer o Call Forward No Answer, Second Level o Hunting (on busy) o Call Forward Busy (Direct Inward Dial (DID) Calls Only) o Call Forward and Hunt by Call Type Call Forward All Calls ====================== Description ----------- This feature is also known as Divert All Calls on other systems. The Call Foward All Calls feature allows an extension user, to unconditionally divert their incoming calls to another extension or to an external number. The forwarding number can be changed at any time by the extension user from their set. This feature can be assigned to both analogue and digital sets, but if assigned to a digital set it must be programmed onto a key. For systems that have Meridian Mail, the extension user can divert their calls to Mail by keying in the access DN for Meridian Mail. The feature called "Remote Call Forward" allows an extension user to Program their Call Forward DN from a remote set. Implementation -------------- - Analogue Sets The Call Forward feature (CFW) is assigned to analogue sets using Overlay Program 10. The maximum number of digits allowed in the forwarding number must be specified, the valid entries are 4, 8, 12, 16 or 23. - Digital Sets The Call Forward feature (CFW) is assigned to a key on a digital set using Overlay Program 11. The key number must be specified along with the maximum number of digits allowed (4, 8, 12, 16 or 23) in the forwarding number. The extension user can be restricted to forwarding their calls to internal destinations only by setting a Class Of Service to CFXD (Call Forward External Denied). Example ------- In this example Call Forwarding is assigned to analogue TN 9 3 and Call Forward External allowed. >LD 10 REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM FTR CFW 16 {Call Forward All Calls to numbers with max. 16 digits} FTR ITEM CLS CFXA {Call Forward to external numbers allowed} ITEM REQ END {Exit} On a digital set TN 7 4 Call Forward is to be assigned to key 3 and Call Forward External denied. >LD 11 REQ CHG TYPE 2008 TN 7 4 ECHG YES ITEM KEY 3 CFW 8 {Allocate to key 3 Call Forward All Calls to numbers with a maximum of 8 digits} KEY ITEM CLS CFXD {Call Forward to external numbers denied} ITEM REQ END {Exit} Call Forward No Answer ====================== Description ----------- This feature is also known as Call Forward On No Reply. With Call Forward No Answer a call that is not answered after a set number of rings will automatically forward to an alternative extension. The feature cannot be activated/deactivated by the extension user and the forwarding DN cannot be changed by the extension user. The number of rings before a call diverts is set on a system wide basis between 1 and 15 rings (4 is the default). For systems that have Meridian Mail, the extension user can elect to have their calls forward on no answer to Meridian Mail specifying the access DN for Mail. Call forward no answer will only work single step i.e. once a call has been forwarded after 4 rings to another extension and it is not answered at that second extension, it will ring indefinitely unless the extension has "Call Forward No Answer, Second Level" assigned (see next feature). Implementation -------------- The feature is assigned in two steps. First the Class of Service must allow Call Forward No Answer (FNA), and then the number to which calls are to be forwarded must be defined. This is known as the Flexible Directory Number (FDN). Example ------- In this example Call Forward No Answer has been assigned to analogue TN 9 3 and the calls will divert to DN 2205. >LD 10 {Load Program 10} REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM CLS FNA {Allow the Call Forward No Answer feature} ITEM FTR FDN 2205 {The Flexible DN is 2205} FTR ITEM REQ END {Exit} In this example Call Forward No Answer has been assigned to digital TN 7 4 and the calls will divert to DN 2205. >LD 11 {Load Program 11} REQ CHG TYPE 2008 TN 7 4 ECHG YES ITEM CLS FNA {Allow the Call Forward No Answer feature} ITEM FDN 2205 {The Flexible DN is 2205} ITEM REQ END {Exit} Call Forward No Answer, Second Level ==================================== Description ----------- Call Forward No Answer will normally only work single step i.e. once a call has been forwarded on no answer to a second extension it will ring indefinitely at that extension; if however the second part has a Class of Service Secondary Call Forwarding Allowed (SFA) then the call will, after a set number of rings, forward to a third DN as defined in the Flexible Directory Number (FDN) of the second set. Implementation -------------- The feature is assigned to both analogue and digital sets by setting the Calss of Service to SFA. The FDN must also be defined to identify where the calls will be forwarded. Example ------- In this example Call Forward No Answer, Second Level has been assigned to an analogue TN 9 3 and the call will be forwarded to 2205. >LD 10 REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM CLS SFA {Allow Second Level Call Forward No Reply} ITEM REQ END {Exit} Hunting ======= Description ----------- This feature is also known on other systems as Divert on Busy. This feature allows a call which encounters a busy extension to automatically Hunt (forward) to a predefined DN. If the extension that is hunted to is also busy the system will look at the Hunt DN of that second set and Hunt (forward) again to that DN. This continues until an idle DN is found. The Hunt DN is set on a per extension basis and cannot be changed or disabled by the extension user. For systems that have Meridian Mail, the extension user can have their calls hunt on busy to Meridian Mail in the same way as hunting to another extension. This is achieved by specifying the access DN for Mail instead of an extension number. Hunting to Meridian Mail will however preclude the use of some features like Ring Again. The maximum number of hunt steps is as follows: For Option 11, 51, 61 systems = 18 steps For Option 71 systems = 30 steps [ On most systems, the hunt number on all the sets will usually be the extension number of the receptionist or secretary - Snk ] Implementation -------------- The feature is assigned to both analogue and digital sets by allowing the feature in the Class of Service and also defining the Hunt directory number. Example ------- In this example Hunting has been assigned to an analogue TN 9 3 with the calls to be forwarded to DN 2432. >LD 10 REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM HUNT 2432 {Hunt to extension (DN) 2432 when busy} ITEM CLS HTA {Allow Hunting} ITEM REQ END {Exit} Call Forward Busy ================= Description ----------- This feature is set on a per extension basis, and allows for Direct Inward Dialling (DID) calls only, that encounter a busy extension, to be forwarded to the Attendant Console if all the steps in the hunting chain are busy. Implementation -------------- The feature is assigned to both analogue and digital sets in the Class of Service. Example ------- In this example Call Forward Busy has been assigned to an analogue TN 9 3. >LD 10 REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM CLS FBA {Allow Call Forward Busy} ITEM REQ END {Exit} Call Forward and Hunt by Call Type ================================== Description ----------- This feature allows internal and external calls to be routed to different destination DNs under Call Forward No Answer and Hunting situations. Implementation -------------- Note that to implement this feature there are a number of data items, associated with routes, that cannot be changed by the sysadmin. Analogue and Digital Sets ------------------------- The feature is assigned in the Class of Service. Then four directory numbers must be input to define: o the DN where internal calls are to forward to on no answer o the DN where internal calls are to hunt (forward) to on busy o the DN where external calls are to forward to on no answer o the DN where external calls are to hunt (forward) to on busy Example ------- In this example Call Forward and Hunt by Call Type has been assigned to analogue TN 9 3. >LD 10 REQ CHG TYPE 500 TN 9 3 ECHG YES ITEM CLS CFTA {Call Forward and Hunt by Call type allowed} ITEM FTR FDN 2205 {Destination for Internal calls not answered} ITEM HUNT 3341 {Destination for Internal calls encountering busy} ITEM FTR EFD 2731 {Destination for External calls not answered} ITEM FTR EHT 3421 {Destination for External calls encountering busy} ITEM REQ END {Exit} Call Hold, Permanent ==================== Description ----------- This feature allows an analogue extension to place an established call on hold when desired. This feature is not required on digital sets as they have a dedicated Hold key. The analogue extension user places the call on hold by following these steps: - Press the "Recall" key - Enter the FFC for Call Hold (#55 is the default) - Replace the handset - To take the call off hold and speak to the caller again simply lift the handset There is a system wide Permanent Hold Recall Timer which specifies the maximum length of time that a call can be left in the permanent hold state. If this timer expires the system will automatically call the user back and reconnect them to the original caller. Whilst the caller is on hold they hear silence unless the "Music on Hold" is equipped. Permanent Hold also requires that the set has the Call Transfer feature allowed. Implementation -------------- The feature must be assigned in Overlay Program 10 and the Class of Service must allow Call Transfer (XFA). Example ------- In this example the Permanent Hold feature has been assigned to TN 9 1. >LD 10 REQ CHG TYPE 500 TN 9 1 ECHG YES ITEM CLS XFA {Transfer allowed} ITEM FTR PHD {Permanent Hold feature assigned} ITEM REQ END {Exit} Call Party Name Display ======================= Description ----------- This feature allows a name of up to 24 characters in length to be associated with a DN or an access code of a route. When the DN is called it will display the name associated with the called DN on the calling party's display module. Analogue sets and digital sets without a display can have a name associated with their DN that will automatically be sent as they originate calls. Implemention ------------ The Class of Service for both the calling and called extensions must be set (in LD 10 or LD 11) to allow Call Party Name Display. The name to be displayed is set in LD 95, which is also used to print all existing names and DN associations. Example ------- In this example a name has been associated with DN 2302. Note DN 2302 (TN 7 5 ) is assigned to a digital set which has a display module fitted. The example also shows how a name can be associated with the access code of a route (eg. 1500) to enable extension users to easily identify where calls are coming from. >LD 95 REQ NEW TYPE NAME CUST 0 DIG {Names can be assigned to "Dial Intercom Group" members, but just return through this for now} DN 2302 {DN is specified} NAME Alan Smith {Name assigned to DN 2302} XPLN 24 {Set the maximum name length to 24} DN 1500 {Access code for Route 0} NAME BT Route 0 {Name assigned to Route 0 (an exchange line)} XPLN 24 DN {No more names to add so return here} REQ PRT {Print out names to check} TYPE NAME CUST 0 PAGE DIG DN ALL {All names are to be printed} SHRT YES {Short format for printout} The system responds by printing a list of DNs and names assigned to them: 0 ATTENDANT 1500 BT Route 0 1501 BT Route 1 2202 Janet James 2302 Alan Smith REQ END {Exit program 95} Now we need to add the Call Party Name Display feature to the set: >LD 11 REQ CHG TYPE 2008 TN 7 5 ECHG YES ITEM CLS CNDA {Call Party Name Display Allowed. This enables the displaying of incoming names} ITEM REQ END {Exit} Call Restriction (Barring) ========================== Description ----------- - Restriction to Outgoing Routes Using this process an extension user can be barred from using particular routes out of the system. Each outgoing route can be assigned to up to 32 TARGs (Trunk Access Restriction Groups) which are numbered between 0 and 31. Each extension also has a data item called TGAR (Trunk Group Access Restriction) to which only one number, between 0 and 31, may be defined. The extension user is denied from using the route when the TGAR of that extension matches one of the TARGs of the route. In the diagram below extension 2731 is barred from using routes 0, 1 and 2. Extension 2211 is barred from using route 0. [ ahem, yeah er..sorry about the ascii art (those boxes on the left are the sets) :] - Snk ] ------ +==============+ | Ex. | +==============+ | 2731 |---------->> | | BT Exchange - Route 0 (TARG 1,4) ------ | P.B.X |---->>-------------------------->> TGAR 4 | | | | Private Route 1 to Site B (TARG 2,4) | |---->>-------------------------->> | | ------ | | Private Route 2 to Site C (TARG 3,4) | Ex. |---------->> | |---->>-------------------------->> | 2211 | +==============+ ------ +==============+ TGAR 1 +---------+---------------------------+ | TGAR | Restriction Applied | +---------+---------------------------+ | TGAR 1 | No access to BT exchange | | TGAR 2 | No access to site B | | TGAR 3 | No access to site C | | TGAR 4 | No access to any routes | +---------+---------------------------+ - Restriction by Class of Service Another method of barring calls is by applying one of six alternatives in the extension's Class of Service. The six Class of Service types are: UNR - Unrestricted The extension user can dial anywhere they want - literally without restriction. FRE - Fully Restricted No exchange line access. The extension user can make internal calls, can use privately wired (Tie) lines, however they can have calls using exchange lines transferred to them from another extension user. FR1 - Fully Restricted 1 Same as FRE but calls using exchange lines cannot be transferred to them. FR2 - Fully Restricted 2 This restricts the extension to internal calls only. SRE - Semi-Restricted Allowed outgoing external calls via the attendant console only. Can recieve external incoming calls. TLD - Toll Denied Allowed outgoing calls to certain destinations only. The Meridian 1 monitors the digits that are dialled to determine if the call is to be allowed. This process is called New Flexible Code Restriction. - New Flexible Code Restriction Each individual extension, that has a Class of Service of TLD, will have a NCOS - Network Class of Service defined. The value assigned to NCOS will ultimately identify a call barring table (TREE), that contain the numbers that are permitted or denied from being dialled. Up to 8 trees can be defined on Meridian 1 and these are identified by NCOS 0 to 7. Option 11 Default Settings -------------------------- The default Option 11 system comes with the trees set as follows, however they can be customised to suite: NCOS 0 = TREE 0 No Barring (i.e. Unrestricted) NCOS 1 = TREE 1 Bar Everything except 112 (New European Emergency Number) and 999 NCOS 2 = TREE 2 Bar any numbers beginning with 0 or 1 with the exception 112, 0800 and 0345 NCOS 3 = TREE 3 Bar 010 (International), 0898 and any number beginning with a 1 with the exception of 112 NCOS 4, 5, & 6 Spare NCOS 7 = TREE 7 No Barring (i.e. Unrestricted) Implementation -------------- The type of call restriction applied to an extension is configured in the Class of Service using Program 10 (analogue sets) or 11 (digital sets). These programs are also used to define the extent of teh restriction using the TGAR and NCOS prompts as appropriate. Example ------- This example shows three different extensions being set up for the following call restriction: TN 9 1 Totally Unrestricted TN 8 4 Restricted from gaining access to any route with a TARG of 3 TN 7 4 Restricted from dialling international numbers and 0898 numbers as detailed in default TREE 3 >LD 10 REQ CHG TYPE 500 TN 9 1 ECHG YES ITEM CLS UNR {Class of Service set to Unrestricted} ITEM TGAR 0 {No Trunk Group Access Restriction is applied} ITEM REQ END {Exit} >LD 11 REQ CHG TYPE 2616 TN 8 4 ECHG YES ITEM CLS UNR {Class of Service set to Unrestricted} ITEM TGAR 3 {Restrict this extension from accessing any route with a TARG of 3} ITEM REQ END {Exit} >LD 11 REQ CHG TYPE 2008 TN 7 4 ECHG YES ITEM CLS TLD {Toll Denied causes the system to look at the NCOS value for this extension} ITEM NCOS 3 {NCOS 3 causes Code Restriction Tree 3 to be applied to this extension} ITEM TGAR 0 {No trunk group Access Restriction is applied} ITEM REQ END {Exit} Call Transfer ============= Description ----------- This feature allows an extension user to transfer an established (answered) call to another extension. The feature can be assigned to both analogue and digital extensions. Implementation -------------- For analogue sets set the Class of Service to allow Call Transfer (XFA). For digital sets assign the transfer feature (TRN) to a key. Example ------- In this example the Transfer feature has been assigned to analogue TN 9 6. >LD 10 REQ CHG TYPE 500 TN 9 6 ECHG YES ITEM CLS XFA {Allow "Transfer"} ITEM REQ END {Exit} In this example the Transfer feature has been assigned to key 3 of digital TN 8 2 >LD 11 REQ CHG TYPE 2008 TN 8 2 ECHG YES ITEM KEY 3 TRN {Assign "Transfer" feature to key 3} KEY ITEM REQ END {Exit} Call Waiting ============ Description ----------- This feature notifies an extension user, currently engaged on an established call, that another call is waiting to be answered. On a digital set notification is by a flashing lamp associated with the Call Waiting key and a buzz tone through the loudspeaker of the set. On analogue sets notification is by two bursts of tone through the ear-piece of the handset. The user can put the first call on hold, answer the second call, and return to the first call when desired. The analogue set uses a FFC, and the digital extensions must have a dedicated key. There is an option to notify that internal calls and/or external calls are waiting. Implementation -------------- For analogue sets, allow the Class of Service Call Waiting (CWA), Internal Call Waiting (SWA) and Warning Tone (WTA). For digital sets, allow the Class of Service Internal Call Waiting (SWA) and Warning Tone (WTA). The Call Waiting feature must be allocated to a key. Example ------- In this example Call Waiting has been assigned to analogue TN 9 8. >LD 10 REQ CHG TYPE 500 TN 9 8 ECHG YES ITEM CLS CWA SWA WTA {Call Waiting, Internal Call Waiting and Warning Tone allowed} ITEM REQ END {Exit} In this example Call Waiting has been assigned to key 4 on digital TN 7 0. >LD 11 REQ CHG TYPE 2616 TN 7 0 ECHG YES ITEM CLS SWA WTA {Internal Call Waiting and Warning Tone allowed} ITEM KEY 4 CWT {Call Waiting allocated to key 4} KEY ITEM REQ END {Exit} Conference ========== Description ----------- This feature allows an extension user to add additional parties to an established call. The maximum number of parties allowed in conference is six and only one of the parties may be external. To establish a conference call the extensiom user would follow these steps: Analogue Sets Digital Sets ------------------------------------------------------------------------ Press Recall Key Press Conference Key + + Dial the number of the extension that is to be added to the call + + If free, the 3rd party extension rings. After answer a speech link is established that excludes other conference members. To establish a conference proceed as follows: + + Press Recall Key again Press the Conference Key again Repeat these steps to add additional extensions. Implementation -------------- For analogue sets the Class of Service must be set to allow Call Transfer (XFA) and Conference (C6A). For digital sets Conference (AO6) must be assigned to a key. Example ------- In this example the Conference feature has been assigned to analogue TN 9 3. >LD 10 REQ CHG TYPE 500 TN 9 6 ECHG YES ITEM CLS XFA C6A {Transfer and 6 Party Conference allowed} ITEM REQ END {Exit} Distinctive Ringing Groups (DRGs) ================================= Description ----------- The Meridian 1 system provides four different ringing candences which may be assigned to digital sets. The four can best be described in terms of frequency and rate of change as follows: DRG Pitch and Rate of Change --------------------------------------------- 1 Low and Fast 2 Low and Slow 3 High and Fast 4 High and Slow The Meridian 1 system can also br programmed to ring extensions differently for internal and external calls. This is set up by BT personnel and is set on a system wide basis. Implementation -------------- The Class of Service is set to identify which of the 4 ringing cadences should be applied to the TN. Example ------- This example shows how DRG3 has been assigned to TN 8 3. >LD 11 REQ CHG TYPE 2616 TN 8 3 ECHG YES ITEM CLS DRG3 ITEM REQ END Group Call ========== Description ----------- This feature allows many, predefined, extensions to be called simultaneously at the press of a key on a digital set. As each extension answers they automatically enter the conference call. Analogue sets cannot initiate a Group Call however they can be included in the group. The maximum number of members in a group is 20. The maximum number of groups on a system is 64. Implementation -------------- The members in the group (extensions) are defined in a list using Program 18. After the list has been defined the Class of Service, for each extension in the group must be set to Warning Tone Allowed (WTA) and the feature needs to be programmed to a key for any digital set that is to initiate the group call. Example ------- This example shows how a Group Call List (22) has been set up to call four extensions (2206, 2401, 2405, 2406). It also shows how the feature has been assigned to key 4 on TN 7 13. >LD 18 REQ NEW TYPE GRP {Define type to Group Call} CUST 0 GRNO 22 {Define the group number} GRPC YES {YES indicates that the originator of the group call controls the call i.e. if the controller clears down, then everyone in the group is cleared down. If this field is set to NO and the originator of the group call clears down everybody will remain in conference until they clear down themselves} STOR 0 2206 {DN 2206 is input into store 0} STOR 1 2401 STOR 2 2405 STOR 3 2406 STOR {No more extensions to add, so just Return here} REQ END {Exit} Now change the Class of Service to WTA for each group member and allocate the feature to a key for each member that is to originate the group call: >LD 11 REQ CHG TYPE 2616 TN 7 13 ECHG YES ITEM KEY 4 GRC 22 {Assign Group Call for list 22 to key 4} ITEM CLS WTA {Allow Warning Tone} ITEM REQ END {Exit} EOF. ------------------------------------------------------------------------------- . : | +--> VoIP <--+ | : +--> re-load VOICE OVER INTERNET PROTOCOL SAID TELEWEST ========================================== What is VoIP ??? ---------------- Voice over IP (VoIP) is one of the most active areas in telecommunications today. As data traffic is growing much faster than voice traffic, there has been considerable interest in transporting voice over data networks as opposed to the more traditional data over voice networks. Most large carriers are looking at this new technology. TRADITIONAL TELEPHONY VERSUS VOIP --------------------------------- The public switched telephone network (PSTN) is the largest network in the world and is 99.999% reliable. It is a circuit switched system where a dedicated 64Kb path is set up between the two telephones. This link is reserved for the duration of the call, whether conversation is taking place or not, and so is wasteful of bandwidth. (see included voipnet.jpg) VoIP is a packet switched system. The phone call is broken into packets of data, which are sent to the destination using the Internet Protocol (IP). At the far end the packets are re-assembled and converted back to speech. Packets from many phone calls, as well as data can travel down the same path. By using compression techniques and withholding packets containing silence, further gains in bandwidth utilisation can be achieved. APPLICATION OF VOIP ------------------- Voice communications will certainly remain a basic form of interaction for all of us. The immediate goal for VoIP is to reproduce existing telephone capabilities but at a significantly lower cost. However, increased competition in today's telecom market means Telewest is always looking to provide new services and applications. VoIP will allow us to introduce innovative new products, quickly and at competitive rates compared to existing services. Ultimately, wide deployment of IP telephony will cause a wave of new applications and services that will fundamentally change the way people use technology to communicate. VOIP AND TELEWEST ----------------- As a first step towards implementing IP telephony, Telewest is currently conducting a "Proof of Concept Trial" of VoIP over cable within our Integration Test Platform (ITP) located at Knowsley. Marconi has been selected to run the trial and supply the backbone infrastructure. The purpose of this trial is to start Telewest on a learning curve for this new technology and to assess the ability of our network to support this new service. If initial test on the ITP prove successful, Telewest plan to offer the service to a number of trial customers. Phase two, starting this year, will be to select a preferred solution from a number of key vendors and roll out a commercial platform in a number of regional sites for Alpha/Beta trials. Telewest's ultimate goal is to create a national IP telephony platform from which we can offer VoIP using all access methods, be it cable, DSL, or wireless. Re-LoaD ( #darkcyde idler ) . : | +--> Modem Brown Box <--+ | : +--> Phractal Modem Brown Box By Phractal. Using your modem as a bridge for two seperate lines to create '3-way calling' This is a common scenario that many dialup users of the interenet have on their computers. Many people have two phone lines at home, for the convienience of being connected to the internet via telephone and also being able to use the other line for voice calls. In this diagram, we start out with two seperate phone lines, each having their own unique telephone number of course. One line supplies Phone A with access to a dialtone. Line two plugs directly into the modem. Almost all telephone modems have two phone jacks. One is meant for the incoming phone line (ie the line coming from the wall), and the other is meant to attach to phone (Phone B), which can be used when the modem is not in use, and will operate on the same line as line 2, naturally. This is where 'I' and 'O' labeled on the modem come into place. The 'I' stands for input, and the 'O' stands for output. On many modems, the input jack is labeled 'Line', and the output jack is labeled 'Phone'. When the modem is not in use, think of it as a router for Line 2 to Phone B. *POTS lines from wall Line 1 Line 2 Phone Line Modem Line |~| |~| | | | | | | /----------\ | | | | | | /-------------\ | Computer | /----------\ | | | | | | | @@@@@@@@ | _______ \-------| TDM <--+ | : +--> foneman -------------------------------------------------------------------------- Time-Division Multiplexing by foneman -------------------------------------------------------------------------- The problem of transmitting multiple signals over a single-wire circuit was one of the earliest challenges to telecommunications inventors. It was pretty clear that this challenge needed to be conquered seeing as how costly it was to install wire circuits. The solution was sought after to solve the problem for sending multiple telegraph signals over a single-wire circuit. One early way to transmit more than one signal over a single-wire circuit was by use of a phantom circuit. Over already existing wire pair circuits, an additional signal was transmitted through the use of transformers at each end of the circuit. This type of signal was known as a phantom signal. Although the phantom circuit solved the problem of transmitting more than one signal over a wire circuit, it only solved it to some extent. The only way more phantom signals could be transmitted over the wire circuit pair was if the technique was extended to more wire circuits, which was still very costly and still only allowed one phantom signal per pair circuits. Multiplexers ------------ Eventually multiplexing was invented. A multiplexer, often called a mux, allows several devices to transmit a signal over the same transmission medium. For example, if you have a high-speed circuit and you wanted to run several low-speed terminals off of it you could run the terminals through a multiplexer. This is obviously a major advantage. Multiplexers are normally used in pairs, with one at each end of the communications circuit. The multiplexer connected to the terminals can combine the data and send it over the communications circuit, then the multiplexer on the receiving end would the separate the data and send it to the correct ports. Before I get into multiplexing, a few things need to be said so that the rest of the article is understood. From this point on a multiplexer will be refered to as a mux, as it often is. The low-speed ports of a mux will be refered to as branch ports and the high-speed port as the trunk port. The branch ports of a mux are usually connected to terminals or front end ports and the trunk port to the communications circuit. Two muxes connected by a communications circuit is illustrated below to give you a visual if you had any trouble with that. Mux A Mux B ___________ ___________ | | | | * | | * * #=========================# * * | | * * | | * |___________| |___________| = Communications circuit * Branch port # Trunk Port Note: The two muxes shown in the above diagram are only connected to each other. In a realistic situation the branch ports would probably be connected to terminals on the sending end and a front end processor, or FEP, on the receiving end. Pure Time-Division Multiplexing ------------------------------- When you have a high-speed communications circuit that's being used by several low-speed devices the muxes use a technique known as time- division multiplexing, or TDM. In my first example of TDM, shown in the diagram below, four terminals and front end ports are operating at 1200 bps. The modems between the muxes each operate at 4800 bps. All four terminals and front end ports share the same bandwidth of 4800 bps. Host computer _____________ Terminals | | ___ | | FEP _| | | | ________ Mux Mux | |___| | | | | ______ Modem Modem ______ | ___ | | | |--| | ____ ____ | |-- | | | | | |--| |_|____|_____|____|_| |----|___| | |___| |--| | | |-----___ |_____________| |________|--|______| |______|-- | | | |___| _|_ | | |___| Obviously you can see that if all four terminals were constantly transmitting and receiving data, there would be a total of 4800 bps transmitted and received by the modems. Since there is a 4800 bps connection between the modems and only four terminals and front end ports operating at 1200 bps there will always be enough bandwidth to handle all of the terminals' maximum operations. How does Pure Time-Division Multiplexing Work? ---------------------------------------------- At this point I'll discuss the two most popular methods of pure time-division multiplexing; character interleaving and bit interleaving. In character interleaving, also known as byte interleaving, one character is multiplexed at a time. A diagram will be given below to help you to better understand what's being explained in this section. So things don't get messy, only four terminals (each sending a one word message simulatiously) will be used. Terminal 1 sends "Phreaker," terminal 2 sends "Linux," terminal 3 sends "Fetus," and terminal 4 sends "Ajax"; all words are sent one character at a time by the terminals. The mux connected to the terminals will be mux A, and the mux connected to the front end processor will be mux B. Using character interleaving, mux A scans it's branch ports for characters transmitted by the terminals. Should mux A receive any characters to be sent over the high-speed trunk port, they can be sent over it one at a time. For example, mux A scans it's branch ports and discovers the characters P, L, F, and A. Mux A sends these characters over it's trunk port to mux B. Mux B then sends the characters to each front end port at 2400 bps. The P is sent to port 1, the L to port 2, the F to port 3, and the A to port 4. Next, mux A sends 'hiej' over its trunk port. Mux B then sends h to port 1, i to port 2, e to port 3, and j to port 4. This goes on until every character is sent. Host computer _____________ Terminals | | ___ | | FEP _| 1 | | | ________ Mux B Mux A | |___| | | | | ______ Modem Modem ______ | ___ | | | |--| | ____ ___ _ | |-- | 2 | | | | |--| |_|____|____|____|_*| |----|___| | |___| |--| | | |-----___ |_____________| |________|--|______| |______|-- | 3 | | |___| _|_ | 4 | |___| * Byte interleaving time slots and their data Time slot: 12341234123412341234123412341234 Data: PLFAhiejrntaeuuxaxs-k---e---r--- Every time a front end port is communicating it's called a time slot. In the example I just gave, terminal 1 had the first time slot, terminal 2 had the second time slot, terminal 3 the third, and terminal 4 the fourth. When the data reaches mux B, the first time slot is sent to front end port 1, the character in the second time slot is sent to front end port 2, and so on. However many devices are used with TDM, there would be that many time slots instead of four. For example, if there were 10 terminals instead of just four, there would be 10 time slots. Time slots aren't always used, as the example of terminal 4 sending the message "Ajax" shows. This just means that bandwidth goes unused. Every terminal is guaranteed enough bandwidth because the speed of the trunk port equals that of the speeds of the terminals combined. The other mentioned method of accomplishing TDM is bit interleaving. As opposed to sending one character from each terminal, this method takes one bit from each terminal and sends it on the trunk port. Imagine that terminal 1 sends the character F (01000110), terminal 2 sends O (01001111), terminal 3 sends N (01001110), and terminal 4 sends a E (01000101). We'll ignore start and stop bits to make it simpler. Since in ASCII the bit on the right is transmitted first, the first bit received from terminal 1 is 0, from terminal 2 is a 1, from terminal 3 is a 0, and from terminal 4 is a 1. 0101 is then sent by mux A over the trunk port. Mux B receives the data and sends the first time slot to front end port 1, the second time slot to front end port 2, the third time slot to front end port 3, and the fourth time slot to front end port 4. Since in bit interleaving, the time slots are shorter, there are eight times as many time slots in a second. In this case too, the speed of the trunk port has to be equal to the speeds of the terminals combined. The two methods function identically, except for the fact that there is a bit in each slot instead of a byte. * Bit interleaving time slots and their data Time slot: 12341234123412341234123412341234 Data: 01011110111101100000000011110000 Statistical Time-Division Multiplexing -------------------------------------- Due to the fact that humans take breaks, screw around on the job, and type slower than their terminals can transmit, users generally don't use all of the available bandwidth. Because of those reasons, character transmission is usually very intermittent. In a situation where this happens more often than not using pure TDM, time slots are left empty. Statistical time-division multiplexing (STDM) takes full advantage of the intermittent nature of terminal users and does it's best to make available bandwidth to each terminal when needed. When using an STDM mux, also called a stat mux, the combined speeds of the terminals in use do not have to equal that of the transmission speed in the trunk port. For example, six terminals at speeds of 2400 bps can use a trunk port transmitting at 9600 bps. This is due to the nature of STDM in that it assumes not all devices are transmitting all the time. Since in STDM, time slots are not sent on a constant basis the question of how the stat mux knows which data goes to which port? Typically, a stat mux sends an address along with the data. When a terminal is not sending any data, other terminals transmitting can use the time slots. Another question comes to mind when speaking of STDM. What happens when all terminal users attempt to transmit data at the same time? Since the data can't all be transmitted at once, a stat mux will generally buffer the data until a terminal user stops sending data so that there would be extra time slots available on the trunk. Closing ------- Obviously you can see which method of TDM would be most efficient in a case of intermittent transmission or in constant transmission. I hope that I was able to shed a little light on what's happening to your data as it's sent. foneman . : | +--> UK Trunking Network <--+ | : +--> hybrid UK Trunking Network Primer. by hybrid Written for F41th and 9x April 2001 ----------------------------------- The Local Distribution Network (Local Loop) =========================================== At the lowest level in the UK PSTN hierarchy, customers Terminal Equipment (TE) is connected to the Local Loop, which physicaly comprises of cables and copper. The Local Distribution Network provides the TE with access to the Local Exchange either via a standrard copper connection, where the connection to the exchange is analogue, and then conversion from the exchange to the PSTN is digital, or via a direct digital link (FAS Flexible Access Systems) from the TE to the Local Exchange. A Logical Local Distribution Network ==================================== P <--> +----------+ +-------+ Exch Side +-------+ S <--> | Local | +------>| PCP |<---------->| SCP | T <--> | Exchange | | ###| |############+-o-o-o-+ N <--> | MDF | | # +-o-o-o-+ Dist Side | | | +-------+--+ | # | | | | | | CC | | # | | | | | |<------+ # | | | +-------+ # | | +---------+ ############################## | +---------+ | +--------------+ | | | | | | | | +------R+D------+ +------F+T-+ +-O+D------+ | | | | | | | | | | | | | | +--+-+ +--+-+ +--+-+ +--+-+ +--+-+ +--+-+ +--+-+ | TE | | TE | | TE | | TE | | TE | | TE | | TE | +----+ +----+ +----+ +----+ +----+ +----+ +----+ RD = Radial Distribution (Underground Cables) FT = Frontage Tee Distribution OD = Overhead Distribution CC = Cable Chamber PCP = Primary Cross - Connect Point SCP = Secondary Cross - Connect Point MDF = Main Distribution Frame ### = Exchange Side/Distribution Side Barrier UK PSTN Node Hierarchy ====================== The UK PSTN is a complex array of network nodes that operate on a partent-child hirarchy, operating right from the top of the chain (International Exchange Boundarys) down to RCUs and RSSs to customers TE. BT implement a particular system known as System X, which will be covered later in this file. A basic layout of the UK PSN is as follows: +---------------+ | International | | Gateway | +---+---+-------+ DDSSC = Digital Derived | | Services Switching | +-------------------+ Centre | | +---+---+ +---+---+ +---------+ --> D | DMSU O<------------->O DMSU O<-------->O| DDSSC | --> D | | | | | | --> S +-+---+-+ +-+---+-+ +---------+ --> N | | | | | | +---------+ | DMSU = Digital Main | | | | Swithing Unit | | | | (System X) | +-------------------+ | DLE = Digital Local | | | | Exchange (System X | | | | or AXE10) | +---------+ | | RCU = Remote Concentrator | | | | Unit (System X) +-+---+-+ +-+---+-+ RSS = Remote Subscriber | DLE | | DLE | Switch (AXE10) | O<--------+ +-->O | +---+-+-+ | | +---+-+-+ | | | | | | | | | | | +-------------+ | | | | +------------+ | | | +-o-o-----------+ | | | | | Operator | | | | | | Service Centre| | | | | +---------------+ | | | +---------+ +------------+ | | | | +--+ +---+---+ | +---+---+ | | RSS | | | RCU | | | | | | | | +---+---+ | +---+---+ | | | | | | | | | \ TEs / \ TEs / The International Gateway ========================= The International Gateway, or ISC (International Switching Centre) is a switching centre that will handle international traffic to and from other countries. In the UK There are 5 ISCs that implement AXE10, 5ESS and DMS100 switches. As shown in the diagram above, the ISCs are connected to the inland PSN via System X DMSUs. The UK Trunk Network ==================== ISCs are connected to DMSUs (Digital Main Switching Units) which form the backbone of the UK trunking network. There are approximatly 59+ DMSUs in the UK PSTN which are all fully interconnected and switch/route traffic to and from System X catchment areas, along with around 4 Digital Switching Units (DSUs) which route traffic from London to ISCs via partially interconnected links. The DMSUs are interconnected to the "smaller" nodes in the Local network, forming the connection from the national switched PSN to the Local Level. Aswell as being interconnected to the ISCs, the DMSUs are also connected with the DDSN (Digital Derived Services Network) which provides BT LinkLine services, such as 0800s. The UK Local Network ==================== At the top part of the Local Network are the DLSUs (Digital Local Switching Units) which from the local level in the System X network. A zone will normaly contain more than 2 DLSUs (System X) and/or AXE10 Exchanges. From the 2+ Exchanges in the zone, 1 of them is used as a DCCE (Digital Cell Centre Exchange) or a DLE (Digital Local Exchange). So a DLSU will either be a DLE or a DCCE coupled with a non System X (AXE10 Exchange), Otherwise known as System Y. The DCCE has access to its parent (the DMSU) via its DDF (Digital Distribution Frame). Any other Exchange on this network level, such as AXE10 must also implement the DCCEs Digital Distribution Frame as a means of access to and from the parent DMSU. The DCCE performs variopus functions at a local level, including call charging and Tandem Traffic Switching between other DLSUs on the local network level. The DLSU acts as a parent node for the next type of local exchange, the RCUs (Remote Concentrator Units). In cases where older ALEs (Analouge Local Exchanges) have been replaced with RCUs a DLE will replace the DCCE and and act as a parent for the collection of replaced ALEs forming an RCC (Remote Concentrator Centre). When there are more than one Concentrators in an RCC, this will form an RMCC (Remote Multi Concentrator Unit) Because older ALEs such as TXE4 have no direct interconnection with the main DMSUs, the DCCE will provide them with the function to communicate with the DMSU. It is possible to determine your own Local Exchange type from your TE (Terminal Equipment(Phone)) via Testing the Exchange for Offered Services: System X: A System X type is the only Digital Exchange to offer "Charge Advise Per Call" *40*[DN]#. Also "Regular Reminder Call" *56*[hh/mm]*9# so if your Excahnge excepts these 2 services, it is most likely System X. System Y: "Charge Advice Per Call" this time, *40#[DN] will determine the System Y Exchange Type. If neither of these work, there is a possiblilty that your exchange type is UXD5(Non C7 or Enhanced). In some high call density zones in London, a DJSU (Digital Junction Switching Unit) to handle the high concentration. The TE Customers are connected to a RCU/RSS/ALE via the Local Loop, and the RCU is connected to the DLSU via digital links. The opposite of this is Low density rural areas whereas UXD5 is used. ######TRUNKING#LEVEL################################# ... <------>ISCs<------><----------->DDSSCs-----> ... ... <------>DMSU<------->DMSU<------>DMSU<------> ... | | | | | | ######LOCAL#LEVEL#################################### | | | DLSU DLSU DLSU<---> Other DMSU DCCE DLE DCCE | | | RCU RCU RCU (or RSS AXE10) ALE RCU ALE PCM === Pulse Code Modulation forms the backbone of the UK digital network, including direct links to and from digital Exchanges. One of the main functions of PCM is to convert reproduced analouge voice signals into a digitaly pulsed form, which can then be transmitted over the UK digital Trunking Network. The first part of the PCM proccess is to sample the origional transmission into PAM (Pulse Amplitude Modulation) Signals. This is done by sampling the voice pattern at fast intervals (8kHz on the UK network) into real-time PAM signals which are then encoded into the PCM signal. In order for the PAM pulses to be encoded, they must be treated as strings/samples, and then injected with a standard 8 bit binary string. When the 8 bit binary strings arive at the other side, ie: the destination of the decoder on the network, the binary samples can be decoded back into origional form, where the reconstruction of the PAM signals takes place. Now, because of the time intervals in the sampling rate of conversion, this will leave Spaces for other signals to be injected into the transmission, thus multiplexing occurs. This is more commonly known as TDM (Time Division Multiplexing), where each sample will take a Timeslot. In PCM the samples are converted at a rate of 8kHz, thus creating 32 Timeslots. BT implements a 30 CHANNEL Timeslot system, in which the remnaining 2 CHANNELS are used for Network Syncronisation (TIMESLOT 0) and Network Signalling (TIMESLOT 16), ((Loop Disconnect (LD) type signalling)). During each frame two sets of four signalling bits, (a,b,c,d) are allocated to carry signalling information for 2 traffic channels. Frame Signalling Codes: ======================= a b c d -------------------------------------------------------------------- 1 1 1 1 Circuit Idle Circuit Busy 0 0 1 1 Circuit Seized Answer 1 0 1 1 Dial Break Not Used 0 1 1 1 Not Used Circuit Free 0 0 0 1 Operator Override Not Used (The Operator Override code is a forward signal used to allow an operator to monitor a busy line) 1 0 0 1 Not Used Not Used 1 1 0 1 Not Used Not Used 0 1 0 1 Not Used Not Used 0 0 0 0 Not Used Not Used -------------------------------------------------------------------- +-------+ |TS 0 |< Network | |< Synchronisation +-------+<-----+ |TS 1 | | +-------+ | |TS 2 | | +-------+ | |TS 3 | +- Speech Channels | . | | 1 to 15 | . | | |TS 14 | | +-------+ | |TS 15 | | +-------+<-----+ |TS 16 |< Network | |< Signalling + Allignment Signals +-------+<-----+ |TS 17 | | +-------+ | |TS 18 | | | . | | | . | +- Speech Channels |TS 29 | | 16 to 30 +-------+ | |TS 30 | | CAS (Channel Associated Signalling) +-------+ | =================================== |TS 31 | | +-------+<-----+ Timeslot 0 is injected with allignment signals in the transmission path of the PCM signal, the PCM decoder will then be able to know if the synchronisation rate is correct. The following is a diagram of a PCM encoder/decoder circuit which is implemented in this proccess: PCM CIRCUIT =========== +<-- Ch (4) +---+ | | |-------------->+|<-- Ch (3) +---+ || Low Pass Filters || +---+ || | |------------->+||<-- Ch (2) Receive End ---------> +---+ ||| +--> Ch (16) Ch (1) ||| | +---+ || ||| +-----------------------+ +|--> No Channel #-#-->| |-||--->+||+->O | || Connected AUDIO +---+ || ||+-->O | +||--> Ch (15) |+--->O | ||| ------------------+---->O<----------+<-TS (0) O<----+|| Reconstructed +------->O | TS (16)->O<-----+| PAM Samples |+------>O | O<------+ || +-----------|-----------+ ---------------+| Ch (1)----->| Recognised Signals No Channel | Ch (3)----->|<---- Ch (2) Connected | |<---- Ch (4) | |<---------------------+ ----------------+ +-----------|-----------+ | C Ch (30) | | | o | DECODER | | m | | | m +-------------|---------+ | o . .+........................... . +---+ B P | n . Ch | 1 | i A | . +---+ n M | P . Ch | 2 | a | a Line +---+ r S | t System Ch | 3 | y i | h . +---+ g | . Ch | 4 | n <----------+ F . +---+ a | o . | | l | r . .+........................... . +---+ s | +-------------|---------+ | A | | | l | ENCODER | | l | | | +-----------|-----------+ | C Ch (1)----->| PAM Samples | h Ch (3)----->|<---- Ch (2) | a +<-- No Channel |<---- Ch (4) | n | Connected |<---------------------+ n | +-----------|-----------+ e | Ch (30) ---------->O | | l +---------------------->O | | s +--------------->O<----------+<-- TS (0) | | +--->O O<------+ | |+-->O Channel Sampling O<-----+|<-- TS (16) =A====== ||+->O Switch O<----+|| ==U===== ||| +-----------------------+ ||| ===D==== ||| ||| ====I=== ||| Transmit ||| =====O== ||| End ||| ======|= ||+-> Ch (4) ||| | |+--> Ch (3) Ch (16) <----||+ | +---> Ch (2) No Ch <----|+ +---------------> Ch (1) Ch (15) <----+ Timeslot 16 and CCS (Common Channel Signalling) =============================================== As with CAS, in CCS Timeslot 16 is used for network signalling information such as binary sieze codes etc. In CCS, Timeslot 16 is a 64/kbit channel, (8 bits x 8 kHz), as are the other channels. Digital Exchanges implement CCS for signalling between various other Exchanges, and is based on CCITT7. In System X, the 30 Channel PCM system forms the link between the customer and the Exchange switch (DS3), and from the Excahnge switch to Junction Access. At the Concentrator Unit in the RCC, subscribers lines are concentrated into PCM Channels, upto 2048 lines consentrated to the 8 x 30 PCM channels in each unit. DSSS Subscriber Line Units at the Concentrator: Sub 0 +-------+ Speech +-------+ ------->O O<------------->O L C | | SLU 0 | | i o | ------->O O<------------->O n n | Sun 7 +-------+ Signals | e t | +---------------+ | r | 32TS's| Concentrator | | o O<----->O Switch | | l | | | | l | | | Sub 24 +-------+ Speech | e | +---------------+ ------->O O<------------->O r O<--+ | SLU 3 | | | | ------->O O<------------->O | | Sub 31 +-------+ Signals +-------+ +--> Concentrator Control If the Remote Concentrator becomes Isolated from the Exchange, ie: unable to communicate with the Exchange, Subscribers are still able to set up calls, although calls made in this period of isolation will not be charged due to the charging equipment in the Exchange dependancy on the concentrator. Review ====== IAM Initial Address Message IFAM Initial and Final Address Message ISC International Switching Centre |--> Handle traffic to and from other countries |--> 5 ISCs in the UK: |--> Keybridge | |--> AXE10 |--> Kelvin | |--> AXE10 |--> Mondial | |--> 5ESS |--> Madley(A) | |--> AXE10 |--> Madley(B) | |--> DMS100 |--> Connected to Inland PSTN via DMSUs ISDN Intergrated Services Digital Network |--> ISDN lines tested from dedicated OMC line test system ISUP ISDN User Part IUP Interconnect User Part MTP Message Transfer Part PNO Public Network Operator PSTN Public Switched Telephony Network SCCP Signalling Connection Control Part TUP Telephony User Part ETSI European Technical Standards Institute NCRS Non Circuit Related Signalling GSM Global Systems for Mobile DSU Digital Switching Unit |--> DSUs are found in London |--> Trunk and Network traffic switched to London Boundrys |--> DSUs are only connected to DMSUs in London DMSU Digital Main Switching Unit |--> Parent of DLSU |--> Fully Integrated Trunk Network |--> Switch Traffic to and from Catchment Area |--> System X |--> Manufactured by GEC/Plessey (GPT) DLSU Digital Local Switching Unit |--> Digital Local Processor Exchange |--> Either a DCCE (+) DLE |--> System X (+) AXE10 DCCE Digital Cell Centre Exchange |--> Acts as parent for RCUs |--> Acts as parent for Analouge Exchanges | |--> Terminates Analouge Line plants | |--> Executes call charging |--> Switches Tandem traffic between DLSUs |--> Access to DMSU via DDF (Digital Distribution Frame) DJSU Digital Junction Switching Unit |--> Used in High Density Telecom Areas |--> Tandem Switching Functions |--> No Direct Customer Connections |--> Only in London |--> System X Exchange Type DSSS Digital Subscribers Switching Subsystem |--> Refered to as "DS3" or "D triple S" |--> Consists of Several Concentrators |--> P-Switch (Part of DSSS) DDSN Digital Derived Services Network |--> Connected to the PSTN |--> Provides LinkLine Services 0800/0345 etc |--> Controled by DDSSCs | (Digital Derived Services Switching Centre) | |--> which in turn are controled by: | |--> INDB (Intelligent Network Database) |--> Connects Service Providers to PSTN via DMSUs ALSU Analogue Local Switching Unit |--> Analogue Switched Functions to Customers | |--> Strowger (TXS) | |--> Crossbar (TXK1) | |--> Electronic (TXE2, TXE4) |--> TXE4 system enhanced to implement digital |--> CCS (Common Channel Signalling) ALE Analouge Local Exchange |--> No direct DMSU Links |--> Traffic Forwarded to DMSUs via DCCE DLE Digital Local Exchange |--> A DLSU that hosts RCU on a hierarchial relationship |--> Parent of ALEs replaced by RCUs RCU Remote Concentrator Unit |--> Part of the DLSU via connection |--> System X Concentrator | |--> Concentates large number of lines | |--> Lesser number of PCM channels |--> Maximum number of Terminated lines: 2048 (0-2047) |--> MUST be connected to DLSU RSS Remote Subscriber Switch |--> Same as RCU, but AXE10 RCC Remote Concentrator Centre |--> Multiple RCUs (+) RSSs at one location |--> (RMCC) Remote Multi Concentrator Unit UXD5 CDSS1 (Monarch PABX) Derived Digital Exchange |--> Some depraved Rural areas (being phased out) 5ESS Used in DDSN Network and International Gateway Exchanges DMS Used in International Gateway Exchanges and BT Featurenet AXE10 System Y |--> IOG (Input Output Group) | |--> SPS (Support Processor Subsystem) | |--> MCS (Man-Machine Communication Subsystems | | |--> Alarm Panels, Terminals etc | |--> DCS (Data Communications Subsystem) | | |--> Communications over digital links | | | |--> OMC | | |--> Same as AUS/NIS in System X | |--> FMS (File Management Subsystem) |--> APT | |--> SSS (Subscriber Switching Subsystem) | | |--> Same Concentrator function as DSSS | | |--> LSS Local Subscriber Switch | | |--> RSS Remote Subscriber Switch | |--> TSS (Trunk and Signalling Subsystem) | | |--> Handles connections to other nodes | |--> GSS (Group Switching Subsystem) | | |--> Connects speech paths like DSS | |--> CCS (Common Channel Subsystem CCITT7) |--> APZ |--> RPS (Regional Processing Subsystem) | |--> Scan subscriber lines | |--> Operation of Switches |--> CPS (Central Processing Subsystem) |--> 2 Central Processors (like PUS) TE Terminating Equipment |--> Terminate Customer Line, isolate Exchange |--> Terminating point for each junction OMC Operations and Maintenance Centre |--> Serves Partitioned Digital Exhanges |--> Data collected from Exchages and served to users |--> OMU |--> Traffic OMU Operations and Maintenance Unit |--> Office with engineers monitoring Exchanges | |--> Recieving data from the OMC |--> Multiple OMUs connected to 1 OMC |--> Connected to UXD5 Exchanges via stand-alone terminal |--> Terminals directly connected to the OMC | |--> Control over Exchanges connected to the OMC |--> Bottom of hierarchy |--> System Manager |--> UM (Operations and Maintenance Unit Manager) |--> MCO (Maintenance Control Officer) | |--> TCD (Task Co-ordinating Duty) |--> MO (Maintenance Officer) |--> MOA (Maintenance Officer A) |--> MOB (Maintenance Officer B) DSG District Support Group |--> Bellow PSG |--> BT District Staff PSG Product Support Group |--> Bellow ISOS |--> BT Headquaters ISOS In Service Operational Support |--> Top of hierarchy |--> Manufactures EIR Exchange Incident Report database SLU Subscriber Line Unit TNS Test Network Subsystem LCP Local Control Point GPA General Purpose Test Auxiliaries |--> Monitor |--> Looping and Ring Trip P-Switch Part of DSSS. Analouge switch for concentrating physical test access from the subscriber line to the: Q-Switch Second Switching Stage for subscriber access |--> built from 8x8 2 wire reed switch SIUs R-Switch Access to short handeling time access auxilaries |--> built from 3x3 2 wire reed switch SIUs D-Switch Connects the user into the Test Network |--> Access gained via dedicated DIAL BACK circuit MTN Mini Test Network |--> Test subscriber lines and equipment TAC Test Access Connection PLA Per Line Auxiliarys MDF Main Distribution Frame TOS Temporarily Out Of Service |--> Will still give dialtone when siezed | |--> only 999 and 151 calls can be made |--> To confirm line has been TOS'd make test call to TOS'd line and listen to message, or from the TOS'd line call an un-charged number and await NU tone FT Failure Tone |--> 600Hz at 260Ms on, 260Ms off, 1400Hz at 260Ms off) CPI Cable Pair Identification PCP Primary Cross connect Point |--> SCP (Secondary Cross connect Point) FAS Flexible Access System TRS Transmission Repeater Station PSN Public Switched Network OSC Operator Services Centre VPN Virtual Private Network |--> BT Featurenet PC Private Circuit Network ACE Automatic Cross-connection Equipment PDN Public Data Network |--> PSS (Packet Switch Stream) OLO Other Licenced Operator VAN Value Added Network |--> BT Cellnet PCM Pulse Code Modulation |--> CAS (Channel Associated Signalling) |--> CCS (Common Channel Signalling) PAM Pulse Amplitude Modulation TDM Time Division Multiplexing MML Man Machine Language PUS Processor Utility Subsystem (System X main Processor) DSS Digital Switching Subsystem (Main System X Switch) MTS Message Transmission System (C7 Messages) SIS Signalling Internetworking Subsystem (Analouge) AUS Access Utility Subsystem (System X) NIS Network Interworking Subsystem (OMC Access and Admin) COU Central Operations Unit |--> National Operational functions are performed here |--> Network Traffic Managment NOU Network Operations Unit |--> UK Network is divided into 9 zones | |--> Scotland | |--> North East | |--> North West | |--> N.Ireland | |--> Midlands | |--> Wales and West | |--> Southern Home Counties | |--> Northern Home Counties | |--> London |--> Remote Manipulation of the Network |--> Circuit Provisioning |--> Control of work between NOU and NFU boundarys NFU Network Field Unit |--> Physical Network access (Engineers etc) NACC Network Administration Computer Center |--> 11 in NOU Zones around the UK |--> 1 in Martlesham for emergency fallback |--> NOMS (Network Operations Managment Systems) |--> CSS (Customer Services System) CTU BT Circuit Termination Unit |--> located within the building housing the Operator |--> G703 interface on two 75 ohm coaxial cables direct to either the Operator Switch or an Operator Digital Distribution Frame (DDF) which is co-located with the Operator Switch. ----------------------------------------------------------------------- Shouts to Night, Datawar, Substance, Zomba, Psyclone, Monty, Crypt, grip, euk.... ----------------------------------------------------------------------- EOF D4RKCYDE 1997,1998,1999,2000,2001 F41th Magazine http://www.f41th.com #darkcyde Efnet. mailto: hybrid@f41th.com.