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UC500 and Lync Failures (Lync to UC500 only)

Level 1
Level 1

I have an interesting challenge here. I had Lync 2010 and my UC540 working well together. I used SNR to user Lync extensions and then configured call forward/simultaneous ring to their Mobile phones on the Lync client configuration. That way when a call was made to a user's UC540 extension, their Lync client would also ring (no matter if they were in the office or not) and their mobile would also ring (UC500 initiated calls to mobile phones on behalf of Lync). If no one answers Cisco Unity Express answers and forwards voicemail to email. Really neat little solution.

I then started mucking around with Cisco IP Communicator and made the fatal mistake of doing it via CCA. Anyone that has used CCA knows that it continually makes changes under the hood that you don’t know about that impacts other configurations - as well as has the tendency not to show you the actual config on the UC500 i.e modify Generic SIP trunk detail and then suddenly all my inbound dial plan configs are gone - yet they are not gone, but simply not showing in CCA.......smoke and mirrors to make an integrators life easier..... I digress.

I added 3x IP Communicators via CCA and since then interop between my UC500 and Lync failed. I have spent time analysing and identified a few things that CCA added that impacted the interop and I have rectified all of those things manually. I am now back to the point where things are working again except for one thing.

When you dial an extension of a user on the UC540 from the Lync client. There is no audio heard on the Cisco phone originating from the Lync client. Yet, when I make a call from a Cisco extension to a Lync client extension, audio works in both directions? It is important to note that when the Lync to Cisco call is established (with audio only 1 way from Cisco to Lync) after approx. 19 or 20 seconds, the call is terminated.

The debugs indicates the follwing when the call automatically terminates,

%VOICE_IEC-3-GW: SIP: Internal Error (ACK wait timeout): IEC=

When I look at the IEC description I see this

    IEC Version: 1

    Entity: 1 (Gateway)

    Category: 129 (Call setup timeout)

    Subsystem: 7 (SIP)

    Error: 66 (ACK wait timeout)

    Diagnostic Code: 0

This leads me to believe that a connection does not seem to be getting established? Yet the call is correctly initiated and rings?... Any ideas or experience you could share that may assist me in isolating this would be greatly appreciated.

4 Replies 4

Hi briangormley.

Probably you don't have the latest update, you have to upgrade  your device, after you do this the problem will be corrected. And yes, it has to work in both directions.

If this answer was satisfactory for you, please mark the question as Answered.

Thank you

Greetings, Johnnatn Rodriguez Miranda

Running the latest code?

CONFIG (Version=8.6)


Version 8.6

Cant see anything newer than this?

paolo bevilacqua
Hall of Fame
Hall of Fame

Wrong forum, post in "small business voice - UC500". You can move your post using the actions panel on the right.

Level 1
Level 1

Just an update on this.

After doing some debugs and sniffer analysis we determined that the Lync Server itself was not responding with the SIP: ACK message just prior to the RTPs tream being initiatied.

On the Lync logs, we could see an "internal error:400".

We then made some configuration varible changes in the Lync Server Management Shell, these were

EnableSessionTimer was changed from True to False

EnableReferSupport was change from False to True

After these changes all was opetrational.