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Help With Unique Voice-Port Connection

Level 1
Level 1

We have a sort of unique application with a mobile radio system.  We are using Tait radios, with a Tait DAS (Digital Audio Switch) connected with T1 to a VWIC in order for the router to convert a radio call coming in on TDM to a multicast session to Console units.  The radio calls works most of the time, but for some unknown reason the router is periodically dropping connections from the TDM.  I am trying to find debugs that will tell me what is going on, and ideas as to why the router is dropping audio.  Here is the corresponding configurations:

card type t1 0 0


network-clock-participate wic 0


voice-card 0


controller T1 0/0/0
cablelength short 110
ds0-group 0 timeslots 1 type e&m-immediate-start
ds0-group 1 timeslots 2 type e&m-immediate-start
ds0-group 2 timeslots 3 type e&m-immediate-start
ds0-group 3 timeslots 4 type e&m-immediate-start
ds0-group 4 timeslots 5 type e&m-immediate-start
ds0-group 5 timeslots 6 type e&m-immediate-start

! continues through ds0-group 23


voice-port 0/0/0:4
voice-class permanent 1
input gain 1
echo-cancel coverage 32
no comfort-noise
timeouts call-disconnect 3
connection trunk 1115


dial-peer voice 1115 voip
destination-pattern 1115
session protocol multicast
session target ipv4:
codec g711ulaw
vad aggressive

3 Replies 3

Level 1
Level 1

I forgot to include the following as part of the configuration:

voice class permanent 1
signal timing idle suppress-voice 1
signal timing oos timeout disabled
signal keepalive disabled
signal sequence oos no-action

Felipe Garrido
Cisco Employee
Cisco Employee

The channels should be trunked at all times. can you elaborate on what you see when the connection is "dropped from the TDM" side? Are you seeing the trunks go down? What do you do to get the system back up?


sorry, i have been on the phone with Cisco all day.  My original configurations

were based on configurations supplied to me by the console maker, TPS, and looks to be somewhat old.  The ds0 groups were configured at E&M Immediate-start, and Cisco changed them to e&m lmr.  This seems to have fixed the problem.