NTP NTP 297-1001-100 PAGE 5 PREL., ISSUE 01D03 79 09 21 3. HARDWARE SYSTEM DESCRIPTION CENTRAL CONTROL COMPLEX (CCC) (Figure 2) 3.01 The duplicated CCC is mounted on two adjacent bays. Each CCC contains a group of four units which act together to evaluate incoming messages, to formulate the proper response and to issue instructions to subsidiary units. The four units and their functions are: (a) Central_Processing_Unit_(CPU) Is the the central processor for the DMS system. The CPU has access to memories where stored programs and network data are located. The processor uses this data to decide what action is required to satisfy the needs of the network and issues the commands to carry them out. (b) Program_Store_(PS)_Memory_Module Is exclusively associated with one CPU and is a repository for the program instructions required by that CPU for call processing, maintenance and administrative tasks. The PS associated with the other CPU contains duplicate program instructions. (c) Data_Store_(DS)_Memory_Module Is associated with one CPU and contains transient information on a per-call basis, as well as customer data and office parameters. The other CPU is also associated with a DS containing duplicate data. (d) Central_Message_Controller_(CMC) Controls the flow and priority of messages between the other units of the CCC and the Network Message Controller (NMC) in the various Network Modules (NM), or the Input/Output Controller (IOC). The sub-group of three units (CPU, DS, PS) excluding the CMC, is referred to as the Central Control (CC). Both CPU have access to either CMC which share the message load to the PM. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 6 PREL., ISSUE 01D03 79 09 21 CENTRAL PROCESSING UNIT (CPU) ³ 3.02 The CPU is a high-speed data processor with a microcycle ³ time of 111 nanoseconds and a word length of 16 bits, plus one ³ parity bit. It has two independent parallel memory ports. One ³ port (Program) interfaces with external memory containing variable-length instructions (PS), while the other port (Data) interfaces with the data store (DS). The CPU normally operates in duplicated matched mode with a mate CPU, but can also operate singly. A 36MHz free-running clock provides the basic CPU timing, controlling register gating and clocking, emergency timers and interrupt logic. The 111-nanosecond extendable microcycle period is derived from this clock. 3.03 The CPU uses a register stack to manipulate data internally as well as to and from the data port. The register stack is a high-speed bipolar store containing frequently-used data. This high-speed store, coupled with stack-oriented instructions, contribute to the fast execution speed of the CPU. The CPU contains the microstore and microsequencing logic necessary to execute the program instructions. 3.04 In addition, the CPU contains the following functions required only for dual processor operation: matching, synchronization, inter-machine communication, fault indication and activity control. A match exchange bus (MEB) between the two CPU enables the operation of one CPU to be continuously compared to that of the other CPU. Any asynchronism between the two CPU is ³ detected by maintenance circuitry and appropriate action is taken ³ to change to the alternative CPU. The configuration of the CPU ³ can be controlled and monitored by manual controls and status ³ indicators which are accessible or visible from the front of the unit. MEMORY MODULES 3.05 The Memory Modules used for the PS and DS functions are available in two configurations. One type provides Random Access Memory (RAM) in increments of 16K (K=1024) 17-bit words, while the other type has larger increments of 64K words. The increments of RAM are in the form of Metallic Oxide Semi-conductor (MOS) memory cards which are plugged into the Memory Module. A maximum of 16 active MOS Memory Cards, plus one spare card, can be accommodated ³ per Memory Module. A Memory Module occupies one shelf in the CCC ³ bay. 3.06 A fully-equipped Memory Module of the type using the 16K MOS memory cards, thus has a maximum memory capability of 256K words. The Memory Module using the 64K MOS memory cards has a maximum memory capability of 1024K words, or 1M word. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 7 PREL., ISSUE 01D03 79 09 21 PROGRAM STORE (PS) ³ 3.07 For PS usage, using 16K MOS memory cards, a maximum of two ³ Memory Modules can be used, occupying both of the available shelf ³ spaces in the lower part of the CCC bay. Total RAM capability it ³ therefore 512K 17-bit words. In this case, the DS is located ³ elsewhere, as described in the next paragraph. For a larger PS, ³ 64K MOS Memory Cards are used, providing a maximum RAM capability ³ of 1M word, and requiring one Memory Module. ³ DATA STORE (DS) ³ 3.08 For DS usage, the Memory Module is equipped with special ³ interface and termination cards, which permit the DS to be located ³ either in the lower shelf of the CCC bay (for a small DMS system), ³ or to be located in additional adjaent bays. These additional DS ³ bays, known as Memory Extension (MEX) bays, have space for up to ³ four Memory Modules per bay. The technology and packaging of the ³ DS Memory Modules is otherwise similar to that of the PS. Maximum ³ RAM capability per MEX bay is 1024K words, using 16K MOS memory ³ cards, or 4M words using the 64K memory cards. CENTRAL MESSAGE CONTROLLER 3.09 The Central Message Controller (CMC) acts as a collector/distributor unit for message buffering and routing between the CPU and the Network Message Controllers (NMC) or IOC. As such, it reduces the real time load that the CPU would otherwise incur. The CMC is duplicated and appears on both data port busses allowing access from either CPU. The two CMC operate in load-sharing mode. The side of the CMC which interfaces with the NMC and IOC is referred to as the "peripheral side" (P-side), while the side interfacing with the CPU is referred to as the "CC-side" (C-side). ³ 3.10 Included in each CMC is a system clock which is the source ³ of timing for the network, PM and IOC. The stability of the ³ system clocl is one part in 10-6. The 8KHz framing signal ³ controlling the 32-channel time-division multiplexing is derived ³ from the same source. The clock contains two independent ³ synchronized timing sources derived from 10.24 MHz crystal ³ oscillators. Only one CMC provides timing for the system; the ³ other is in synchronized standby mode. 3.11 Up to 64 Network Message Controllers (NMC) (32 in each plane of the duplicated network) and up to 6 IOC, which drive visual display units, teletypewriters, consoles, magnetic tape units, etc., are connected to the P-side of each CMC. The message links from the CMC to these peripherals are two-way, 2.56 Mb/s asynchronous ac, data channels over which the control and signalling messages flow. The CMC distributes timing to the Network Modules (NM) and, via the NM, to the Peripheral Modules. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 8 PREL., ISSUE 01D03 79 09 21 This ensures that the various components of the system operate at the same rate or a multiple thereof. SWITCHING NETWORK (Figure 3) 3.12 The switching network employs four stages of time switching for each voice connection between the originating PM and the terminating PM. The paths for each connection through the network are assigned under the control of the Central Processing Unit (CPU). The network also distributes the control messages to and from the PM and the CPU. The network is fully duplicated, i.e., Plane 0 and Plane 1, from the originating PM to the terminating PM to achieve the necessary reliability. 3.13 Plane 0 and Plane 1 of the network each consist of a set of up to 32 Network Modules (NM), identified as NM-0 through NM-31, each set of NM forming an identical and independent half of the Network. The NM is the major building block of the plane, and each NM has two sides, as follows: (a) "Receive", Side A (incoming paths from the PM) (b) "Transmit", Side B (outgoing paths to the PM) The separate receive and transmit paths give the network its inherent 4-wire characteristic. 3.14 Each side of an NM provides two stages of time switching, the first stage performed by an incoming crosspoint (IC-XPT) time switch and the second stage by an outgoing crosspoint (OG-XPT) time switch. Each time switch has eight ports (ports 0 through 7), each port handling 32 channels (30 voice + 2 message) between the NM and PM. Each side of an NM contains eight IC-XPT time switches and eight OG-XPT time switches, usually referred to as an 8X8 time switch arrangement. The full capability of an NM is therefore as follows: (a) Number of channels per port = 32 (30 voice + 2 message). (b) Number of ports per time switch = 8. (c) Number of time switches per side = 16 (8 x 8). (d) Total number of ports per side = 64 incoming and outgoing. (e) Total number of channels per time switch = 256 (8 x 32) (f) Total number of channels per side = 2048 (32 X 64). Actually 1920 (30 X 64) voice, and 128 (2 X 64) messages. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 9 PREL., ISSUE 01D03 79 09 21 3.15 Since each side of an NM performs two stages of time switching, the four stages of switching through the network are accomplished by connecting the outgoing ports of the OG-XPT switches in the receive side of an NM to the incoming ports of the IC-XPT switches in the transmit side of the same, or another NM. The connections between receive and transmit sides are called "junctors", and the pattern of connections between NM is dependent on traffic calculations. NETWORK SIZE AND GROWTH 3.16 Since Plane 0 and Plane 1 each require a separate frame, each duplicated network occupies at least two frames. Growth of the network is accomplished by the addition of NM in each plane and rearrangements of the junctors. The full network consists of 32 NM in each plane and occupies 64 frames. It provides 61,440 voice channels in each direction in each plane (1920 channels X 32 NM per plane = 61,440). NETWORK CONTROL 3.17 Each NM contains a Network Message Controller (NMC) which exchanges messages with the Central Control Complex (CCC) and the Peripheral Modules (PM) via the Central Message Controller (CMC). Inputs to the NMC from the CCC come in the form of commands to locate appropriate paths through the network, to establish or release network connections, or to send a maintenance code. Path selection is done under control of software residing in the CCC, based on a network map kept in the Data Store (DS). In the event of loss of the network map in the DS, the map can be reconstructed from information stored in the NMC. A fully-equipped network contains 32 NMC per plane (NMC-0 through NMC-31), or 64 NMC total for both planes. DIGITAL CARRIER MODULE 3.18 The Digital Carrier Module (DCM) provides a direct interface between the DMS digital switching network and digital carrier signals referred to as DS1, which in North America consists of 24 2-way voice frequency channels, time division multiplexed onto a 1.544 Mb/sec bit stream. The DCM extracts and inserts signalling information for interfacing DS1 signals with the DMS-100 Family 32-channel, 2.56 Mb/sec speech links. The DCM is a self-contained shelf having the capability to interface a maximum of five DS1 links (5 X 24 = 120 voice channels) with four 30 voice channel (4 X 30 = 120) speech links. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 10 PREL., ISSUE 01D03 79 09 21 TRUNK MODULE 3.19 The Trunk Module (TM) encodes and multiplexes incoming speech from a maximum of 30 analog trunks into 8-bit PCM speech samples. The TM combines the samples with internal control messages, as well as the trunk supervisory and control signals, for transmission at 2.56 Mb/sec to the network. In the other direction of transmission, the 30 digital speech signals and the two control channel signals received from the network, are demultiplexed and decoded by the TM into 30 individual channels of analog speech and associated signalling. The TM also accommodates service circuits such as MF receivers, announcement trunks, etc., ³ either on dedicated TM or in common with analog trunks. ³ MAINTENANCE TRUNK MODULE, OFFICE ALARM UNIT ³ 3.20 Test circuits are accommodated on a special type of TM, ³ referred to as a Maintenance Trunk Module (MTM). Another module, ³ similar to the MTM, accommodates alarm interface circuits and is ³ referred to as the Office Alarm Unit (OAU). Both MTM and OAU have ³ the capability of interfacing 30 test or alarm circuits with one ³ 32-channel, 2.56 Mb/sec speech link to the network. LINE MODULE 3.21 For local applications, the Line Module (LM) provides voice and signalling interfaces between 2, 3, or 4, 32-channel 2.56 Mb/sec speech links and a concentration of up to 640 analog subscriber lines. LM are installed in pairs on a double-bay frame, with one LM on each bay. LM Controllers (LMC) on adjacent bays operate as reliability mates with separate battery feeds. The LMC contains the PP function. Each LM has access to its own LMC and to the mating LMC to increase reliability. One LM occupies a single bay and has four line shelves and one LMC shelf. Each line shelf contains five line drawers which accommodate 32 line cards each for a total of 640 (4 shelves X 5 drawers X 32 line cards = 640) line cards per LM. ³ REMOTE LINE MODULE ³ 3.22 The Remote Line Modules (RLM) consist of specially-equipped ³ LM which are located remotely, but which operate as peripheral ³ modules of the DMS-100 Family office via DS1 carrier links. ³ Special interface circuits in the RLM transform the usual ³ 32-channel speech link format at the remote end to 24-channel DS1 ³ format for transmission to the office. The office end is equipped ³ with DCM which transform the DS1 signals back to DMS-100 Family ³ speech link format. The RLM provides an economical and efficient ³ method of increasing the serving area of a DMS-100 Local or ³ DMS-100/200 Local/Toll office. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 11 PREL., ISSUE 01D03 79 09 21 PERIPHERAL PROCESSORS 3.21 The Peripheral Processors in the PM (DCM, TM or LM) each consist of a microprocessor with associated Read-Only Memory (ROM), Random-Access Memory (RAM) and Arithmetic and Logic Unit (ALU). The ROM contains "firmware" (fixed instructions) which control the microprocessor as it performs the following local tasks: (a) Scanning the trunk or line interface circuits and detecting a change of state on the associated trunk or line transmission facility. (b) Timing of call processing functions. (c) Collecting and storing dialled digits. (d) Generating digital tones. (e) Sending and receiving signalling and control information to aid from the CCC. (f) Providing integrity checking of network paths between connected PM. INPUT/OUTPUT CONTROLLER 3.22 The Input/Output Controller (IOC) operates similarly to a PM, but its PP communicates directly with the CMC instead of via the NMC. Each IOC accommodates up to nine device controllers (DC), each of which has its own subsidiary PP. There are two types of DC, one provides an interface to one magnetic tape unit on which system data such as Automatic Message Accounting (AMA), or Operational Measurements (OM) are recorded. The other type of DC is a multi-purpose controller capable of handling interfaces with up to four I/O devices. The configurations of the four ports on the multi-purpose DC can be set, via software commands, to match the characteristics of the I/O devices (TTY, VDU, etc.) connected to the ports. 3.23 A special type of IOC is used for the DMS-300 (International) switch application, in addition to the regular type of IOC. This special IOC provides an interface to handle signalling messages in No. 6 CCITT format. The common circuitry and PP of this type of IOC are the same as the regular IOC, but instead of DC, the IOC is equipped with No. 6 Signalling Interface cards. In this configuration, the IOC is referred to as a No. 6 Signalling Shelf. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978