Channel stall when it receives reinvite while in conference


I have noticed some stalled calls (could not be ended with uuid_kill or hupall). From signaling, channel/leg is being originated from FS to telco GW and to a conference on FS (originate … &conference(name)). What is interesting, telco replay with 183/SDP early media (PCMU), and when answering with 200/SDP (PCMU), they do one reinvite to PCMA, then immediately after another one reinvite back to (PCMU). No idea why…

FS - telco
← 100
← 183 (PCMU)
← 200 (PCMU)
← INVITE (PCMA) 1st reinvite
→ 100
→ 200 (PCMA)
← INVITE (PCMA) 2nd reinvite
→ 100

  • it stall here

I have managed to reproduce this with SIPp. What is interesting:

  • if I originate and &park(), there is no problem
  • if I do &conference(name), call stall
  • without a codec change in reinvite, the channel is ok
  • there is no pause between reinvites, they are generated by telco almost immediately. If I add 100ms pause in SIPp between two reinvites, signaling go fine.

I’m running 11.10.8-dev git 98d2e62

Please file a bug report via github, with the SIPP scenario, I think maybe this was fixed already and is in process of heading to the OSS repo… but we need to double check.

Please file the issue.


Hi Brian,

I have opened the issue. Any new info on this?

What is the bug number on github?


Hi Brian,

Sorry to ping you again… Did you get time to check this? Is it case you suspect to be?

No its being looked at today or tomorrow.



I almost forgot about this, but we recently had same/similar issue. FS receive couple 183,180,181,183 and then 200 OK for INVITE but never issue ACK.