NTP NTP 297-1001-100 PAGE 19 PREL., ISSUE 01D03 79 09 21 10. ABBREVIATIONS CC - Central Control CCC - Central Control Complex CCS - One hundred call seconds per hour CDM - Customer Data Modifications CMC - Central Message Controller CPS - Circuit Pack Storage CPU - Central Processing Unit CSM - Channel Supervision Message CDE - Digital Carrier Equipment DCM - Digital Carrier Module DMS - Digital Multiplex System DNI - Digital Network Interconnecting DP - Dial Pulse DS - Data Store DS1 - Primary digital carrier, 24 channels, 1.544 Mb/sec bit rate I/O - Input/Output IOC - Input/Output Controller LM - Line Module LME - Line Module Equipment LMC - Line Module Controller MAP - Maintenance and Administration Position MF - Multifrequency MFR - Multifrequency receiver MIS - Miscellaneous Equipment MS - Message System MTC - Magnetic Tape Center NET - Network NM - Network Module NMC - Network Message Controller ODM - Office Data Modification PCM - Pulse Code Modulated PDC - Power Distribution Center PM - Peripheral Module PP - Peripheral Processor PROTEL - Procedure Oriented Typoe Enforing Language PS - Program Store RAM - Random Access Memory ROM - Read Only Memory TM - Trunk Module TME - Trunk Module Equipment TTY - Teletype VDU - Visual Display Unit VF - Voice Frequency TDM - Time Divison Multiplex DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 20 PREL., ISSUE 01D03 79 09 21 TABLE_A o Frame - Single type of frame for use in the core and peripheral area Dimensions: Width 27 in. (686 mm) Depth 18 in. (457 mm) Height 84 in. (2.1 m) o Shelf Provides 24 in. (610 mm) of usable space between its side plates. Dimensions: Width 26 in. (660 mm) Depth 12.5 in. (318 mm) Height 35.6 cm (14 in.) o Ambient Temperature (~C) Normal: 10 to 30~C Extreme: 5 to 49~C o Relative Humidity Normal: 20 to 50% Extreme: 20 to 80% o Power Nominal: -48 volt battery power plant Normal: -49 to -53.5 volts Extreme: -44.75 to -55.8 volts Note: Extreme conditions may exist for up to 72 hours. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 NTP 297-1001-100 PAGE 21 PREL., ISSUE 01D03 79 09 21 TABLE_B o Call Capacity: 350,000 attempts per Average Busy Season Busy Hour (ABSBH) o Reliability: Less than 2 hours downtime in 40 years. o Grade of Service Local ABSBH 10_HDBH HDBH* Dial tone delay > 3 secs 1.5% max 8% 20% Originating Matching loss (ML) 1.0% max Incoming ML 2.0% max Tandem ML 1.0% 20% Toll 10HDBH HDBH Inc. digit receiver delay 0.5% 2% Tandem ML 0.5% 2% * High Day Busy Hour (HDBH) DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 APPENDIX 1 TO PAGE 1 NTP 297-1001-100 PREL., ISSUE 01D03 79 09 21 CALL DESCRIPTION DMS-100 (INTRA-OFFICE CONNECTION) 1.01 The main components of the DMS switching system and the means by which they communicate are described in NTP 297-1001-100. The way that these components interact in the system is described by following an inter-office call (line to line) from origination to termination. Figures 1 through 5 illustrate the sequence of events in chronological order, starting at the top of each figure. 1.02 Refer to Figure 1. Each line module (LM) has a Peripheral Processor (PP), which continually scans the lines in the module for a change of state. When the PP detects a change of circuit state indicating an OFF-HOOK, a message is sent via the message channel to the Central Control (CC) informing it of the event. 1.03 Upon receiving the OFF-HOOK message, the CC assigns a voice channel on the speech link between the originating LM and the network and assigns an integrity message to the calling line. The CC then begins building a message for the calling LM. This consists of a number of commands, i.e., associate the assigned voice channel with the calling line, begin sending and checking integrity, give dial tone, start receiving digits (assume a DP -dial pulse- origination), and report to the CC after the first digit. (Integrity is a continuity check message, which is transmitted over the voice channel. If a discontinuity in transmission of the integrity message is detected, the connection is automatically switched over to the other network plane.) 1.04 When the first digit has been reported, the CC determines the total number of digits required (7 in this case). A message is then sent to the calling LM to report after 7 digits. When the digits have been reported, the CC translates the digits to determine the location of the called line. Upon reception of all the necessary digits, the CC sends a message to the originating LM to stop receiving digits. 1.05 Refer to Figure 2. The CC determines the location of the called line and assigns a voice channel on the speech link bet called LM and the network. It then sets up a network connection in both planes between the calling and called LM . A message is sent to the called LM telling it to stop looking for an OFF-HOOK on the called line, associate the assigned voice channel, and begin sending and checking integrity. In case the called LM has already reported an OFF-HOOK, the CC commands it to disregard the message. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 APPENDIX 1 TO PAGE 2 NTP 297-1001-100 PREL., ISSUE 01D03 79 09 21 1.06 When the CC receives a message from both LM indicating reception of integrity, the CC sends two messages. It sends a message to the calling LM to start audible ringing and begin scanning for an ON-HOOK, and a message to the called LM to start ringing the called line and begin sending the Channel Supervision Message (CSM) to the calling LM . [The CSM is a digital signal multiplexed over the voice channel which reflects changes of state (answer supervision).] 1.07 Refer to Figure 3. When the called line goes OFF-HOOK, the CSM signal changes state indicating to the calling LM that the called line has gone OFF-HOOK. The calling LM sends a message to the CC that the called party has answered. The CC then sends a message to the called LM to stop ringing the called line. The two parties are now in the talking state. 1.08 Refer to Figure 4. Suppose the calling line goes ON-HOOK. The calling LM sends an ON-HOOK message to the CC. The CC responds with a message to both the calling and the called LM to stop sending and checking integrity. When the CC receives messages from both LM indicating that integrity is stopped, the CC releases the network connection. It then sends a message to the called LM to release the voice channel and start looking for an OFF-HOOK after the called party goes ON-HOOK. The same message is then sent to the calling LM. 1.09 Refer to Figure 5. The disconnect is handled similarly, when the called line goes ON-HOOK first. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 APPENDIX 2 TO PAGE 1 NTP 297-1001-100 PREL., ISSUE 01D03 79 09 21 CALL DESCRIPTION DMS-200 (INTER-OFFICE CONNECTION) 1.01 The main components of the DMS switching system and the means by which they communicate are described in NTP 297-1001-100. The way that these components interact in the system is described by following an inter-office trunk connection from origination to termination. Figures 1 through 4 illustrate the sequence of events in chronological order, starting at the top of each figure. 1.02 Refer to Figure 1. Each Trunk Module (TM) has a Peripheral Processor (PP) which continually scans the trunks in the module for state changes. When the PP detects a seizure, a message is sent via the signalling channel to the Central Control (CC) informing it of the event. 1.03 Upon receiving the seizure message, the CC determines the trunk group type. Suppose the originating trunk is a Multifrequency (MF) trunk. The CC then selects an MF receiver (MFR), assigns an integrity message and voice channels on the speech links between the MFR TM, and the network, and between the seized originating trunk TM and the network. The CC establishes a connection in both network planes between the originating TM and the TM associated with the MFR (MFR TM). It then sends a message to both the originating TM and MFR TM to associate the voice channel and start sending and checking integrity. 1.04 Refer to Figure 2. Once the CC has received acknowledgement from both TM that they are receiving integrity, thus ensuring that the network connection is complete, the CC sends a message to the originating TM to send the start dial signal to the originating office. The received frequencies from the originating office are transmitted over the voice channel to the MFR, where they are translated into digits and stored in the MFR TM. Upon reception and translation of all the digits the MFR TM sends the digits via the message channel to the CC. The CC then sends a message to the originating TM and the MFR TM to stop sending and checking integrity. Once the TM have responded with messages indicating that integrity is stopped, the CC releases the network connection. The CC then sends a message to the MFR TM to idle the MFR receiver. The CC translates the digits from the MFR, determines that a terminating trunk is required, and then finds an idle trunk in a trunk group to the terminating office. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978 APPENDIX 2 TO PAGE 2 NTP 297-1001-100 PREL., ISSUE 01D03 79 09 21 1.05 Refer to Figure 3. The CC assigns an integrity message, and assigns a voice channel on the speech link between the network and the terminating TM. The CC sets up a network connection through both network planes between the originating and terminating TM. Two messages are sent, one to the terminating TM to associate the voice channel, to send and check integrity, and to send the CSM, the other to the originating TM to send and check integrity and to look for the CSM. When both TM respond with messages confirming reception of integrity, the connection through the office is complete. 1.06 The CC then sends a message to the outgoing TM to send the seizure message to the far end office and to look for the start dial signal. When the terminating TM receives the start dial signal, it sends a message to the CC indicating that it has received it. The CC responds by sending the necessary digits over the message channel to the terminating TM. 1.07 Refer to Figure 4. When a disconnect is detected on the originating trunk, the TM sends a message to the CC. The CC sends a message to both TM to stop sending and checking integrity. Upon reception of messages from both TM, indicating that integrity is stopped, the CC releases the network connection. A message is then sent to the outgoing TM to idle the outgoing trunk, followed by a message to the originating TM to idle the originating trunk. DMS-100 FAMILY SYSTEM DESCRIPTION (c) NORTHERN TELECOM LIMITED, 1978