Avaya-Cisco CUBE-Teams Direct Routing Integration

[iisssshhh]

We're trying to integrate our existing Avaya phone system to Cisco CUBE and Teams Direct Routing. We're able to make the Teams outbound calling (Teams to Avaya ext. or external PSTN/mobile) partially work -- we were able to make the callee's phone ring but every time the callee answers the phone, the call disconnects. But this is not the issue I'm asking insights for.

Now, we're trying to make the Teams inbound calling (Avaya to Teams ext.) work, but it keeps failing. The callee's phone (Teams endpoint) doesn't even ring. Looking into the PSTN usage report from Teams admin center, we can see logs that it reached the Teams system, but we cannot find the call ID. Per checking the Cisco SBC logs, we noticed that the SIP logs don't contain any INVITE messages, which we believe will trigger the number lookup in Teams.

Anyone who can provide some insights? We've been in limbo for more than a month now

[Roger Kallberg]

Collect the running configuration of the router and turn on these debugs, debug ccsip messages and debug voip ccapi inout, and collected the output and put this into text files that you attach to your reply. Also please outline called and calling numbers. With that we should be able to have a look at whats going on.

[iisssshhh]

Hi @Roger Kallberg - thank you for your reply. Unfortunately, I cannot share the configuration, and the whole debug logs due to legal agreements. But sifting through the debug logs, I can see these errors:

(1) REASON: Q.850;cause=79;text="78502476-2a0c-4553-b857-bf40d14b7d97;InternalDiagCode: SrtpEncryptionRequired, InternalErrorPhrase: Remote participant did not offer required SRTP support"

(2) posted event:E_STSL_INVALID_PEER_EVENT, reason:4

(3) TCP0: bad seg from xx.xx.xx.xx -- Invalid state: port 1720 seq 2005906823 ack 1733315984 rcvnxt 2005906823 rcvwnd 130714 len 0

(4) TCP0: bad seg from xx.xxx.xxx.x -- outside window: port 54849 seq 2506760945 ack 2503498346 rcvnxt 2506761345 rcvwnd 130672 len 400

I'm open to any insights and suggestions. Thank you so much for your effort and time.

[Roger Kallberg]

Without knowing what the other side is in the debug output that doesn’t offer SRTP it’s hard to give you any advice.

Would it be possible for you to change out any sensitive information in the running configuration and debug output before you post it? It really doesn’t matter if you change out for example called or calling numbers in the debug output as long as you change it consistently. Using search and replace in for example Notepad++ should do that without to much effort.

If this doesn’t work could you at least share the dial peer, voice service voip and SIP profile parts, again obfuscate any sensitive information?

[Jonathan Schulenberg]

If you haven't already reviewed them, Cisco has CUBE interoperability white papers for both of those systems to review as known-working examples.

[iisssshhh]

Hi @Jonathan Schulenberg - thank you for your input. Yes, we followed this guide Direct Routing for Microsoft Phone System with Cisco Unified Border Element (CUBE) but we encountered the issue.

[Guillermo_PY]

Hello @iisssshhh 

As I understand, you have the following scenario:
PSTN --- AVAYA --- CUBE --- MS Teams

From cube perspective you need the following dial-peers:
DP incoming from Avaya
DP Outgoing to Avaya
DP Incoming from MS
DP Outgoing to MS

Looking at the logs, the most relevant error is required SRTP, and the first thing that comes to mind is the command srtp in DP from/to MS.

Could you provide further details while keeping actual IP addresses confidential?

[iisssshhh]

Hi everyone,

Thank you for your time and effort in writing your suggestions to resolve this issue. I'm sorry I took long to respond. Currently, we managed to resolve the SRTP issue in Teams outbound call flow (Teams to Avaya ext. or any external callee) by adding another Cisco SBC that both supported H232 (Avaya) and SIP (Teams) protocols. We're still on ongoing testing and troubleshooting.