RTP Relay only working 50% of the time

[jb3141592]

Hi All,

I have a very strange issue. When using Mobility/callback (dial in > dial back out). I get audio only 50% of the time with RTP Relay (approx.)

I did a packet capture on our firewall and out of the six calls I made. I can see no difference between the three that worked and the three that didn't. I can even see the RTP streams. The telco also see the same thing on there end - no difference between the calls. Also tested with two different telcos (sip trunks) with the same issue.

The only way I can get it to work 100% of the time is to set the codec preference to G729, then it uses the VCM to translate from G711. This obviously has an effect on call audio quality but works every time.

Anyone had a bug like this before?

J

 

[janni78]

It most likely a configuration issue or the firewall doing something it shouldn't like ALG, but it would be easier to tell if you include a SIP trace.

"Trying is the first step to failure..." - Homer

 

[jb3141592]

I've double/triple checked the firewall. No blocks and no ALG.
Attached the packet capture (link), if you want a look at the SIP trace.... I've checked but didn't see anything.

http://94.177.215.233/packet-c_17042020.zip

See included excel file - orange didnt work - green worked.


I am on an old Avaya 9.0.0.0 build 829. Worth an upgrade maybe?

 

[janni78]

You're sending the internal IP in the INVITE as receiver of RTP.

Do you have Network Topology configured on the trunk?

"Trying is the first step to failure..." - Homer

 

[jb3141592]

Hi Janni78,

Yes sending the Internal IP, the teclo is manipulating that bit on there end. I could never get it to send the public IP when I was setting it up, no matter how much I played with the 'Network Topology' settings.

Thanks J

 

[janni78]

You're still on 9.0 GA?
That release was horrible, you should at least get to a later service pack.

"Trying is the first step to failure..." - Homer

 

[jb3141592]

Yep, its a very old inherited system. I hate it - I'm normally a Cisco call manager guy.
Where is the best place to get the bin files / upgrade files for the newest 9.X I can go to?
Sorry if its obvious - really new at this Avaya system.

 

[jb3141592]

Well, spend the night upgrading to 9.0.11 build 1003
still have the same issue totally confused

 

[jb3141592]

I spun up a test FreePBX with all the same settings (Network/SIP/IP's etc...) and shutdown the Avaya.
All calls working fine with FreePBX and RTP Relay. So nothing on the firewall/network that is causing this issue.
Defiantly something wrong with the Avaya.

Long term will probably migrate to FreePBX and decommission the Avaya Junk.

 

[IPGuru]

keepalives!


Do things on the cheap & it will cost you dear

 

[jb3141592]

Hi IPGuru,

RTP Keepalives was one of the 1st things I checked. They are on. Normal calls are working fine - just RTP Relay via Mobility.

J