Avaya 03-300430 User Manual

Page of 2574
TDM-BUS (TDM Bus)
Issue 1 June 2005
2237
 
TDM-BUS (TDM Bus)
S8700 | 8710
 / 
S8500
 
Description
Each port network has a pair of TDM buses, designated TDM bus A and TDM bus B, each with 
256 time slots. This division allows for duplication of control channels and dedicated tone time 
slots. The first five time slots on each bus are reserved for the control channel, which is active 
on only one bus at a time in each port network. The next 17 time slots are reserved for system 
tones such as dial tone, busy tone and so on. As with the control channel, these time slots are 
active on only one bus, A or B, at a time. The rest of the time slots on each bus are for general 
system use such as carrying call-associated voice data. The 17 dedicated tone time slots that 
are inactive can also be used for call processing when every other available time slot is in use.
When the system initializes, the control channel is on TDM bus A and the dedicated tones on 
TDM bus B in each port network. If a failure occurs on one of the two buses, the system will 
switch any control, tone and traffic channels to the other bus. Service will still be provided, 
though at a reduced capacity.
The set tdm PC command has the effect of putting both the control channel and tone time 
slots on a specified bus, A or B. P specifies the port network’s number, and C specifies the TDM 
bus, A or B. Throughout this discussion, PC refers to a specific TDM bus. References to port 
circuit packs
 include every circuit pack that terminates on the TDM bus, including the Expansion 
Interface TN570, and the following service circuit port boards: Call Classifier (TN744), 
Integrated Announcement (TN750), Maintenance/Test (TN771), Speech Synthesizer (TN725B), 
Tone Detector (TN748 or TN420). Other terms used are:
Control Channel Bus: the TDM bus carrying the active control channel
Non-Control Channel Bus: the TDM bus with the inactive control channel
Tone Bus: the TDM bus carrying the active tone time slots
Non-Tone Bus: the TDM bus with the inactive tone time slots
MO Name
Alarm Level
Initial Command to Run
1
1. P is the port network number. Use list cabinet to find the port network(s) 
contained in a cabinet.
Full Name of MO
TDM-BUS
MAJ
test tdm P
TDM bus
TDM-BUS
MIN
test tdm P
TDM bus
TDM-BUS
WRN
test tdm P
TDM bus