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One-Way Audio on a conferencing bridge

I have an interesting one.

Hardware conferencing bridge with 3925

From any IP phone model I get the following:

IP phone to PSTN call G.711  connected

Conference another PSTN call connected G.711 (all audio works)

DSP in use on the bridge verified.

When one of the PSTN caller drops, one way audio occurs.  (PSTN call can hear IP phone, but not vice versa).

Im stumped.  Its the same config I have used just about everywhere for my loopback, Gig, SCCP CCM, binding the interfaces, etc.  Something is happening when the voice call is handed off the DSP back to the router.  You hear multiple disconnect beeps as the first PSTN caller drops.

Where should I be looking next?  It seems fairly odd. 


Everyone's tags (4)
Hall of Fame Super Red

One-Way Audio on a conferencing bridge


Long time my friend

Just curious what version of CUCM?



"Every fool's got a reason to feelin' sorry for himself" - Springsteen

One-Way Audio on a conferencing bridge

8.6.x   Its quite odd.  I guess some traces are needed...    Everything works fine with internal IP phones with the DSP bridge.  Something with the hand off from DSP to T1 port going on.  (or so it seems)  and of course.. bug tool is down.   I have been swamped lately, havent had a chance to play around the forums lately or as much as I would like to.

One-Way Audio on a conferencing bridge

IOS Bug in 15.1.x 

New Member

One-Way Audio on a conferencing bridge

I don't suppose you have the bug reference to hand do you?

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