| ==Phrack Inc.== | |
| Issue XIV, File 5 of 9 | |
| _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ | |
| |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| | |
| |_| |_| | |
| |_| Understanding the Digital Multiplexing System |_| | |
| |_| Part II |_| | |
| |_| |_| | |
| |_| by Control C |_| | |
| |_| |_| | |
| |_| An Advanced Telecommunications, Inc. Production |_| | |
| |_|_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _|_| | |
| |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| | |
| DMS switches were first introduced in 1979. Since then it has been modified | |
| to interface with numerous types of switches. DMS has the ability to | |
| interface with SP-1, #5 XBar, 1ESS, 2ESS, 3ESS, 4ESS, NX1D, NX1E, TSD, SXS, | |
| ETS4, NO. 1 EAC, NO. 2 EAX, NO. 3 EAX, TSPS, CAMA/3CL boards, Stromberg | |
| Carlson Turret of ONI and Visual Indicators, Modified North Electric TSD for | |
| ONI, Stomberg Carlson (CAMA operator Position - ONI/ANI), AE #31 Switchboard, | |
| Co-located NT/AE switchboard I/C, O/G, UDC data poller of OM, DACS (Directory | |
| Assistance Charging System), NT #144 LTD, WECO #14 LTD, WECO #16 LTD, CALRS | |
| (Centralized Automated Loop Reporting System), Badger 612A, AE #1 and #21 LTD, | |
| AE #30, SC #14 LTD, Lordel MITS70 line Test System, Porta System Line Test | |
| Unit, Pulsar II IMTS, Teradyne loop test unit, and the WECO MLT 1 (Mechanized | |
| Loop Testing System). | |
| Common Channel Interoffice Signaling | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| Common Channel Interoffice Signaling (CCIS) is a way of signaling and a way of | |
| implementing network level services. CCIS provides reliable, crystal clear | |
| data signaling links between the network and the switching offices. The CCIS | |
| signaling method uses transmission equipment that is separate from voice | |
| trunks. | |
| Common Channel Interoffice Signaling No. 6 | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The basis for the CCIS system is the International Consultative Committee on | |
| Telephone and Telegraph (CCITT) No. 6 international standard, which is brought | |
| to its fullest capacity for use in the Stored Program Control (SPC) network of | |
| AT&T. | |
| The CCIS6 network contains a bunch of signaling regions, each having a pair of | |
| interconnected Signal Transfer Points (STP). The switching systems put into | |
| CCIS6 that connect to STPs are called Serving Offices (SO). | |
| Band Signaling (CCIS-BS) is used on trunk signaling for intertoll-type trunks | |
| using the CCIS network. | |
| Direct Signaling (CCIS-DS) is used for signaling between SPC switching | |
| machines and a Network Control Point (NCP). At the present time, CCIS6 can | |
| handle Enhanced INWATS Originating Screening Office (OSO), Calling Card | |
| Validation (CCV), Mechanized Calling Card Service (MCCS), and Billed Number | |
| Screening (BNS). CCIS6 is available with DMS-100/200, DMS-200, and | |
| DMS-100/200 or DMS-200 with TOPS. | |
| CCIS6 Diagram: | |
| NSB ST | |
| ------------ - - - - - - - - - - - | |
| DTC | | | ------- | | |
| - - - DS30 | IPML | DS30 | - - - | || | | | |
| --------| |------|- - - - - - |------|-| |---| || | | | |
| Digital - - - | | | - - - | || | | | |
| Trunks | | | | || | | | |
| | | | ------- | | |
| | | - - - - - - -|- - - - | |
| DTC | | TM | | |
| DIG - - - DS30 | NUC | DS30 - - - ----- | |
| --------| |------|- - - - - - |--------| |----| | | |
| ^ - - - |Network | - - - ----- | |
| CCIS \ ------------ Modem | |
| Signaling \ | | |
| - - - ----- | |
| AN Links--| | | CCC | | |
| - - - ----- | |
| Channel | |
| Bank | |
| Acronyms: | |
| DIG - Digital | |
| AN - Analog | |
| DTC - Digital Trunk Controller | |
| MSB - Message Switch Buffer | |
| ST - Signaling Terminal | |
| TM - Trunk Module | |
| NUC - Nailed-Up Connection | |
| IPML - Inter-Peripheral Message Link | |
| Common Channel Interoffice Signaling No. 7 | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| Common Channel Signaling (CCS) No. 7 or CCIS7 is a CCS system based on CCITT | |
| No. 7. CCIS7/CCS7 on the DMS switch consists of two parts: the Message | |
| Transfer Part (MTP) and the Interim Telephone user Part. They are compatible | |
| with DMS-100, DMS-200, DMS-100/200, and DMS-100/DMS-100/200 with TOPS. | |
| CCIS7 can't tell the difference between banded and direct signaling. CCIS7 | |
| uses Destination/Origination Point Codes (DPC/OPC) to route back to the | |
| switch. | |
| CCIS7 can handle Automatic Calling Card Service (ACCS), Enhanced INWATS, Local | |
| Area Signaling Services, and Direct Service Dialing Capabilities. | |
| Equal Access | |
| ~~~~~~~~~~~~ | |
| The DMS-200 Access Tandem (AT) gives a traffic concentration and distribution | |
| function for interLATA traffic originating and a distribution function for | |
| interLATA traffic origination or terminating inside a Local Access and | |
| Transport Area (LATA). This gives the interLATA Carrier (IC) access to more | |
| that one end office inside the LATA. It can handle InterLATA Carrier access | |
| codes (10xxx), 10xxx and 950-yxxx dialing, Automatic Number Identification | |
| (ANI) on all calls, answer supervision, equal access Automatic Message | |
| Accounting (AMA) for both originating and terminating calls, and operator | |
| service signaling. | |
| The DMS-100 EA gives direct and tandem switched access service inside the LATA | |
| for originating and terminating to interLATA Carriers. It is available in the | |
| following three ways: | |
| Equal Access End Office (EAEO) | |
| ------------------------------ | |
| DMS-100 Equal Access End Office (EAEO) gives a direct interconnection to | |
| interLATA Carriers' (IC) and international Carriers' (INC) Points of Presence | |
| (POP) inside the LATA. | |
| Access Tandem with Equal Access End Office | |
| ------------------------------------------ | |
| The DMS-200 Access Tandem (AT) when used with equal access end office (EAEO) | |
| lets trunk tandem interconnect to ICs/INCs POP inside the LATA. | |
| The connection of the Equal Access End Office (EAEO) to an IC/INC through the | |
| DMS-200 Access Tandem (AT) uses what is called two-stage overlap output | |
| pulsing which makes the time it takes to set up a call quicker. The AT uses | |
| the digits OZZ + XXX out pulsed in the first stage to identify the IC/INC | |
| dialed and to pick out outgoing trunk. Then a connection is established from | |
| the IC/INC to the EAEO through the AT. The second stage digits consist of ANI | |
| and the called numbers are passed through the DMS-200 AT at the IC/INC. | |
| An AMA terminating record in AT&T format is produced by the DMS-200 for all | |
| the EAEOs. A per call terminating AMA record is made for calls that get to | |
| the stage where the trunk from the IC/INC has been seized and a "wink" has | |
| been returned by the DMS-200 AT. | |
| Access Tandem with a Non-Equal Access End Office | |
| ------------------------------------------------ | |
| DMS-200 AT using a non-equal access end office gives trunk tandem connection | |
| to an IC/INC POP within the LATA. To set up a call, connection of Feature | |
| Group B (FGB) or Feature Group C (FGC) End Office to an IC/INC through the | |
| DMS-200 AT uses the standard Bell Central Automatic Message Accounting (CAMA) | |
| signaling. The Access Tandem uses the XXX digits of the access code 950-YXXX | |
| out pulsed from the FGB end office to identify the IC/INC and to connect to an | |
| outgoing trunk. | |
| Mechanized Calling Card Service (MCCS) | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The fraudulent use of calling cards, third number and collect calls and the | |
| increasing movement to automate current operator services has directly led to | |
| the implantation of the Mechanized Calling Card Service (MCCS) to DMS-200/TOPS | |
| and to the remote and host Operator Centralization (OC). | |
| MCCS uses CCIS to relay queries and responses to and from the DMS-200/TOPS. | |
| Operator handled calling card calls and the direct entry by subscribers of | |
| Calling Cards by DTMF (Touch-Tone) telephones are given special provisions by | |
| the MCCS. Both the operator handling and the direct entry of calling card | |
| calls are decreasing the size of the operators. | |
| Billed Number Screening (BNS) gives an enhancement to the operator-handled | |
| collect and third-number billing by using CCIS to screen a number at the | |
| billing validation data base for billing restrictions (i.e. the third number | |
| is a fortress). This feature naturally will reduce fraudulent use of the | |
| collect call feature. | |
| Common Channel Interoffice Signaling-Direct Signaling (CCIS-DS), which is | |
| the feature that the MCCS is designed around, is used to transmit messages to | |
| and from many possible Billing Validation Centers (BVCs). Messages | |
| transmitted to the BVC about MCCS include the billing number and the Personal | |
| Identification Number (PIN). In BNS the messages have the special billing | |
| number (collect or third number). The return messages from the BVC include | |
| validity (of the number), billing restrictions (if any), and the Revenue | |
| Accounting Office (RAO) code. | |
| Auxiliary Operator Services System | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The DMS-200 Auxiliary Operator Services System (AOSS) is used primarily for | |
| Directory Assistance and the intercept needs that are not included in the TOPS | |
| package. The AOSS is similar to TOPS and co-exists with TOPS on the DMS-200 | |
| Toll system. | |
| Major benefits of the AOSS include: Directory Assistance is provided with a | |
| modern environment, AOSS position administrative activities are performed by | |
| the DMS-200 toll maintenance system, trunking savings are achieved by | |
| combining trunking for 1+, 0+, and Directory Assistance traffic, DA services | |
| are managed by using TOPS methods, creation of a built-in training system | |
| which does not require additional training equipment and reduces training | |
| costs. | |
| Integrated Business Network | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The Integrated Business Network (IBN) is a revenue-producing concept designed | |
| for small and big businesses to offer modernized PBX and Centrex features. | |
| The Operating Company can use the IBN to maintain and enhance its competitive | |
| position on a operational DMS-100 and DMS 100/200 switches. While using the | |
| DMS-100 switch, the Operating Company can support varying business features | |
| along with existing local/toll traffic. | |
| IBN services can be introduced to a Centrex-Central Office (CO) or a | |
| Centrex-Customer Unit (CU) by additional software modules and minor hardware | |
| enhancements. | |
| Current IBN features include: A growing system that can handle 30,000 lines, | |
| networking capabilities, city wide service for DMS-100 switch and remotes for | |
| any one customer Station Message Detail Recording (SMDR), which gives IBN | |
| customers call records. The records can be used for system analysis and | |
| control and station charge-back. SMDR can use LAMA records (if the IBN host | |
| has LAMA equipment), centralized attendant maintenance, and administration | |
| functions and Direct Inward Dialing (DID). | |
| Electronic Switched Network (ESN) | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The Electronic Switched Network is designed to meet the telecommunication | |
| needs of large multi-location corporations. The ESN is made up of a SL-1 or | |
| SL-100 Digital Business Communications System with networking features or a | |
| DMS-100 IBN host. The SL-1 can handle from 30-5000 lines. The SL-100 and the | |
| DMS-100 IBN hosts can hold from a few thousands to 30,000 lines. | |
| A DMS-100 IBN or SL-100 can remotely serve many locations from the host site. | |
| This is done by a connection through digital transmission facilities which are | |
| set up at remote modules at the subscriber's premises. | |
| Here are some diagrams showing the differences between normal private | |
| telecommunications networks and ESN networks. | |
| Normal telecommunications network | |
| ================================= | |
| ----- ------ | |
| [Phone]--| SnS | | SL-1 |-[Phone] | |
| | PBX | | PBX | | |
| ----- ------ | |
| | |DOD/DID DOD/DID| | | |
| | ------- ------- | | |
| |Tie | | Tie| | |
| |Trunk --------- Trunk| | |
| ------| Class-5 |------ | |
| ----| Centrex |---- | |
| | --------- | | |
| | | | |
| | | | |
| | | | |
| ----- Tie Trunk --------- | |
| | SnS | ----------| Class-5 | | |
| | PBX | | Centrex | | |
| ----- --------- | |
| | | | |
| | | | |
| | | | |
| | | | |
| ------- ------ | |
| [Phone]-| Small | | SL-1 |-[Phone] | |
| | PBX | | | | |
| ------- ------ | |
| ESN Network | |
| =========== | |
| -------- ---------- | |
| [phone]--| Remote | | SL-1 PBX |--[phone] | |
| | Module | | ESN Main | | |
| -------- ---------- | |
| | | | |
| | DS-1 Facility | DS-1 Facility | |
| | -------------- | | |
| --------> | Local Class 5| <--------- | |
| [phone]---------| DMS-100 | | |
| ----| IBN/ESN |------------- | |
| 2W Loop MFIDP | -------------- | ESN Trunk Group | |
| or DS-1 | | | or DS-1 | |
| | ----- --------------- | |
| | | CSC | | Local Class 5 | | |
| -------- ----- | DMS-100 | | |
| | SL-100 | <--- DS-1 ----> | IBN/ESN | | |
| -------- Facility --------------- | |
| | | | |
| | | | |
| | DS-1 Facility | DS-1 Facility | |
| | | | |
| -------- ---------- | |
| [phone]--| Remote | | SL-1 PBX |--[phone] | |
| | Module | | ESN Main | | |
| -------- ---------- | |
| Specialized Common Carrier Service (SCCS) | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| The DMS-250 Specialized Common Carrier Service (SCCS) provides the capability | |
| of Analog to Digital (A/D) and Digital to Analog (D/A) conversions which are | |
| necessary with analog circuits. The DMS-250 can also switch voice and data | |
| circuits. | |
| The DMS-250 takes either analog or digitally encoded info and by using time | |
| slot interchange, switches it from any input port to a temporary addressed and | |
| connected exit port. The info may or may not be converted back to analog. | |
| Cellular Mobile Radio Service | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| A cellular system consists of two main parts: a cellular switch and cell site | |
| equipment. | |
| Cellular Switching Systems | |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| A cellular switch performs three main functions: audio switching, cell site | |
| control, and system administration. | |
| The DMS switches provide three basic implementations for cellular switching: | |
| Stand-alone, Combined, and Remote. | |
| Stand-alone switching is done by a Mobile Telephone Exchange (MTX) which is | |
| interfaced with one or more class 5 end offices. The connection is made by | |
| DID/DOD trunks. Depending on the needs of the area, the MTX can be divided as | |
| follows: MTX which serves urban areas, MTXC which handles suburban areas, and | |
| MTXM which is used for rural areas. | |
| Combined switching is incorporated into a DMS-100 by some hardware additions | |
| and cellular software. Combined switching is designed to give an easy, | |
| cost-effective way to install cellular services to an existing host. | |
| Remote Switching is done by combining Remote Switching Center (RSC) with a | |
| Cell Site Controller (CSC). This combination is hosted by either a | |
| stand-alone or a combined switch. Remote Switching is designed for serving | |
| suburban centers, remote areas, or a small community and it gives extra | |
| flexibility for a growing system. | |
| All of these cellular switches have the ability to balance the workload among | |
| various cell sites. For example, if one site's workload reaches the | |
| programmable level of congestion, calls would be routed to nearby sites that | |
| can handle the extra calls. | |
| Cell Site Equipment | |
| ~~~~~~~~~~~~~~~~~~~ | |
| Cell site equipment consists of a CSC and radio equipment. The CSC is | |
| controlled by the cellular switch and it controls radio equipment and | |
| maintenance tasks. The CSC will work on any MTX cellular switch because of | |
| the Remote Cluster Controller (RCC). | |
| The radio equipment consists of self-contained Radio Channel Units (RCU), | |
| antennas, transmitter multi-couplers, and receiver combiners. | |
| By different program software, an RCU can perform voice, control locating, and | |
| test functions. The self contained nature allows the RCU be remotely located | |
| to the CSC. A RCU has built-in circuitry for extended testing of the radio | |
| part of the system. | |
| Control C | |
| <End of File> | |
| <May 1987> | |
| ______________________________________________________________________________ | |