CSCvb77629 - CTS intermittently fails DTLS negotiation on latest 1.10.15

[SC_Collab]

Does this bug also affect IX 9.1.1? Logs from one of our IX units today after a report of dial failures:

2020-11-23 22:54:47: INFO Local user dialing [removed].[removed]@[removed].webex.com
2020-11-23 22:54:50: INFO Main Video negotiated Frame Rate is 30fps.
2020-11-23 22:54:50: INFO Connected to [removed].[removed]
2020-11-23 22:54:51: INFO Negotiated Media Configuration: LTRP: Disabled GDR: Enabled High Profile: Disabled Cabac: Disabled
2020-11-23 22:54:51: INFO Endpoint used protocol MUX version 8 for this call
2020-11-23 22:54:51: INFO The presentation has been negotiated to 30 & 5 FPS
2020-11-23 22:54:52: INFO BFCP Status: Negotiated
2020-11-23 22:54:52: INFO Active Control Status: Disabled
2020-11-23 22:55:00: INFO Audio DSCP Current Marking: [BE], Previous Marking: [BE]
2020-11-23 22:55:00: INFO Audio COS Current Priority: [0], Previous Priority: [0]
2020-11-23 22:55:00: INFO Video DSCP Current Marking: [BE], Previous Marking: [BE]
2020-11-23 22:55:00: INFO Video COS Current Priority: [0], Previous Priority: [0]
2020-11-23 22:55:02: ERROR Call ended due to bandwidth renegotiation timeout (remote DN: [removed].[removed])

[wuerfelu]

Hello,
i have the same error with an IX 5000 running "IX.9-1-2-9R-K9.P3"
I have this when i dial into CVI Interop with MS Teams.
Any Ideas ?

Thanks Ulli

[gwilkens]

Same here with Hybrid Media node and 9.1.1(16) also.

Have you already opened a TAC Case and got Feedback from Cisco?

[jpenn]

Running into the same exact issue when leveraging VMN's our IX's are on 9.1.0(4).  When routing via Expressway works fine. Anybody else resolve this?

[chris.barlow1]

+1 for issue. Any resolution? 

[UC2]

Hello Everyone,

I am facing this issue as well, calls traversing the video mesh servers are not going further after few second it gets disconnected.

from the IX5000 unit I see in the logs

Looking into the IX5000 logs I can see that there is a renegotiation of bandwidth for audio and video towards the CUCM as per below:

2021-09-13 13:54:14.909 [CTRL] [INFO] [tid 27985] ReNegoNewBandwidth: added security overhead for AV: new_video_offer_br=12600000, new_audio_offer_br=281600

2021-09-13 13:54:14.909 [CTRL] [INFO] [tid 27985] ReNegoNewBandwidth: rmtTPTopo=3, local_video_bw_single=4000000 negotiated_video_bw_single=4000000 new_video_offer_br=12Fabiano20217000

2021-09-13 13:54:14.909 [CTRL] [INFO] [tid 27985] ReNegoNewBandwidth: started bw_nego_timer for 10 secs

Then the SIP bye message is due to timeout or no response on this bandwidth renegotiation.

2021-09-13 13:54:24.973 [CTRL] [ERR ] [tid 28349] BwNegoTimeOutCallback: enter, bw_nego_timer timed out, disconnect the call

Before the bye message from the IX5000 this device is sending notify and update messages to call manager I believe asking for renegotiation of Bandwidth but this doesn’t happen.

I am wondering if this is something call manager can manage to respond to this bandwidth renegotiation because I don’t see forward this messages to the video mesh servers in order to adjust the bandwidth or there is some misconfiguration.

At the end the call is disconnected from the IX5000 with this error.

2021-09-07 11:49:48: ERROR Call ended due to bandwidth renegotiation timeout (remote DN: 1313499950)

We have set the local Region configuration in call manager and Region towards video mesh server to 32000 Kbps to  have enough.

did you get any resolution for this issue?

[chris.barlow1]

Did anyone resolve this issue for their deployment?

[UC2]

Hi.

yes I got sorted this issue. 
it was due to CCM ECDSA installed as self signed in our environment.

I did some research regarding this issue, found that RSA can’t be used alone on this from CUCM version 11.0 and above it must use the CallManager-EC certificate. What happened on our scenario is the video negotiation between CUCM and Mesh server was failing. Endpoint (IX5000) was showing that as a Bandwidth issue because at the same time it was asking for the video negotiation and was getting no response!

So call manager ECDSA as self signed it does not seems to work well for call manager and SIPO trunk towards video mesh servers and makes intermittent issue whilst negotiating bandwidth.  once installed new CCM EC signed certificate issue got sorted.