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VVX Series - One Way Audio Issues?

Advisor

VVX Series - One Way Audio Issues?

Hi Guys,

 

Polycom's helpful twitterfolk suggested you might be able to push me in the right direction with this odd audio issue... i've tried just about everything I can think of, so any help would be most appreciated!

 

We have a few VVX 500 & 600 handsets that we’re testing in our environment, but I’m really struggling to get them to play nicely :/ Here’s a quick rundown of what we have going on:

 

1 x Standard Edition, Consolidated Skype for Business Front End Server

1 x Skype Edge Server + Reverse Proxy

1x Trunk to Sonus SBC 1000 with SIP and ISDN connectivity to PSTN.

 

All devices (Lync Server, Sonus Gateway and VVX Handsets), are sitting on the same internal subnet, with no firewalls between them. Callflow seems to work as follows:

 

 The Good:

  • An inbound call works fine. (gateway > S4B > VVX). 2 way audio, and all things are good :)
  • An outbound INTERNAL call (where media is effectively direct between endpoints) works fine.
  • Starting a conference from the VVX works fine. External parties can then be added, and audio is 2-way

The Bad:

 

  • An Outbound EXTERNAL call establishes, but then you get 1 way audio. The VVX can hear the external party, but the external party cannot hear audio from the VVX. Audio from the VVX does not appear to reach the gateway.

 

I would normally assume something amiss on the front end, and of course that’s where I started my digging, but everything appears to be ok. :/

 

I thought perhaps media was being directed somewhere other than the front end, but media bypass is disabled on the trunk. Lync SIP logs show the external leg between the gateway & mediation server, and then the internal mediation server and the VVX handset. Candidates offered during the SIP negotiation messages match this observation.

 

A remote PCAP on the VVX handset shows media is flowing between the front end mediation server and the VVX handset in both directions.  A similar trace on the front end shows it is sending and receiving the SRTP packets to and from the VVX. The ports in use line up with those advertised in the SIP negotiations. - Everything looks good.

 

I have tested several other devices: the Polycom CX500, CX600 (tethered and untethered), SNOM 720, SNOM 780, CX5500 (connected via USB – I have not tested the device standalone) – all of which function correctly without issue – which leads me to believe there’s something specific to the VVX UC stack that’s not quite as it should be?

 

Both devices (VVX 500 & 600) are running the latest firmware (version 5.4), and have had a full factory reset applied. We do not use a provisioning server, so I assume all settings are defaults.

 

Funnily enough, i've tested the phones remotely too. we experience exactly the same behaviour through the edge (dial in ok, dial out 1 way only) - again, other handsets behave correctly.

 

I’ve been digging at this for a few days now and I’m running out of ideas :( I suppose log files could be made avilable if they will help? unless of course you’ve seen something like it before and can tell me off the top of your head what the problem is? :D no? ah well… pouring through logs it is :/

 

Any help or even pointers anyone can provide would be greatly appreciated!! 

 

Cheers!

Nat

Message 1 of 12
11 REPLIES 11
Regular Advisor

Re: VVX Series - One Way Audio Issues?

Please make sure you are on 5.4.0A(5.4.0.10182) 5.4.0 is not supported in a Lync/SfB enviroment. 

Message 2 of 12
Advisor

Re: VVX Series - One Way Audio Issues?

I can confirm that the phones are (were) running 5.4.0A.10182 - but I considered that running the very latest and greatest may be part of my problem, so they've been rolled back to 5.3.012074 where the exact same issue persists :(

 

Thanks for your swift response though James, any other ideas?

Message 3 of 12
Polycom Employee & Community Manager

Re: VVX Series - One Way Audio Issues?

Hello NatHazlett,

welcome to the Polycom Community.

 

The only way to resolve this is raising a Polycom support ticket via your reseller so we can investigate this.

 

Please contact them and have them raise it and if the unit has been purchased from some kind of discounter you may want to provide me with the MAC Address of the unit so I can provide you with who you need to work with.


Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services




<======== Signature / Disclaimer ========>
Please be aware:For questions about the type of support to expect please check here

Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's

Please remember, if you see a post that helped you , and it answers your question, please mark it as an "Accept as Solution".

The title Polycom Employee & Community Manager is an automatic setting within the community and any forum reply or post is based upon my personal experience and does not reflect the opinion or view of my employer.
Poly employee participation within this community is not mandatory and any post or FAQ article provided by myself is done either during my working hours or outside working hours, in my private time, and maybe answered on weekends, bank holidays or personal holidays.
Message 4 of 12
Advisor

Re: VVX Series - One Way Audio Issues?

Thanks for your reply Steffen,

 

I've send you a DM as it seemed more appropriate.

 

Cheers!

Nat

Message 5 of 12
Regular Advisor

Re: VVX Series - One Way Audio Issues?

 

I would defianly get a support case opened.

 

In the mean time you will want to get some data togather support will want this.

Phone application version

Phone revision - on the label with the serial number 

Phone boot log

Phone app log - clear the current log before recreating the issue.

 

On the phone application log you will want you increase the size of the local log from the default 32KB to the max 180KB.

Some log settings that might be helpful.

 

SRTP = Debug

SIP = Debug

 

If you are using a provisioning server the attached log file will set this and a few more things but will over run the logs on the phone pretty quickly.  So you would need the phones app log off the provisioning server.

 

 

 

Advisor

Re: VVX Series - One Way Audio Issues?

Hi James,

 

I'm doing my best to get a support case opened at the moment :D fingers crossed.

 

Also, thanks for the config files :) We don't currently have a provisioning server, but i'm sure i can spin something up if i need it to collect log files and the like. It's pretty straight forward if I recall correctly :)

 

In a rather sad turn, i've blocked out some time over the weekend to give this another go with a fresh pair of eyes. I'll let you know if i manage to get anywhere.

 

Cheers!

Nat

 

 

Message 7 of 12
Occasional Advisor

Re: VVX Series - One Way Audio Issues?

We had similar issues with our near identical setup. Other model phones worked fine, including the Polycom CX series. We raised a support case but it didn't really go anywhere. We ended up working around the problem.

 

Have you tried consultative and blind transfers, especially:

 

External -> Internal VVX, consult transfer -> another Internal VVX

External -> Internal VVX, blind transfer -> any

 

The above scenarios (among others) weren't working for us either.

 

To resolve the blind transfer issue, we had to add a config entry on our provisioning server (call.BlindTransferSpecialInterop="1") This resolves a known issue with blind transfers involving SBC gateways.

 

To resolve the other calling and one-way audio issues, we had to explicitely disable media bypass on the Lync side (Network Configuration, Untick 'Enable Media Bypass'). We needed to do this, even though it was disabled on the trunk.

 

Our SBC is running firmware v4.1.2 but we tested most versions since 3.2. We also tested a number of VVX versions. We couldn't go back too far with those because we required features from the later releases.

 

 

Message 8 of 12
Polycom Employee & Community Manager

Re: VVX Series - One Way Audio Issues?

Hello adbl,

welcome back to the Polycom Community.

Could you kindly provide the Polycom support reference usually starting with 1- so I can cross reference this post ?


Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services




<======== Signature / Disclaimer ========>
Please be aware:For questions about the type of support to expect please check here

Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's

Please remember, if you see a post that helped you , and it answers your question, please mark it as an "Accept as Solution".

The title Polycom Employee & Community Manager is an automatic setting within the community and any forum reply or post is based upon my personal experience and does not reflect the opinion or view of my employer.
Poly employee participation within this community is not mandatory and any post or FAQ article provided by myself is done either during my working hours or outside working hours, in my private time, and maybe answered on weekends, bank holidays or personal holidays.
Message 9 of 12
Highlighted
Advisor

Re: VVX Series - One Way Audio Issues?

Hi Adbl,

 

Thank you for your reply, it's been very helpful!  I've not yet set the special interop flag, but i was aware it was probably required in our environment. - our work around for that was to set the default transfer type to consultative :) I'll play with that later.

 

Interesting to hear that media bypass needed to be disabled under network config too! that's something i've not testied - i wonder what behaviours change as a result of that setting, given that the trunk was bypass disabled already? That said, we confirmed that all calls were routing through the mediation server as we'd expect using wireshark captures on all three elements- but still had the one way audio issues when dialing outbound from the handsets (even though RTP packets were flowing in both directions between all elements). - we too we running the Sonus SBC on version 4.1.2.

 

In a last ditch effort (as unfortunately polycom wouldnt allow me to open a support ticket) weI upgraded our SBC to the lastest versoin 5.0.1.399 image and this HAS resolved the issue! (blind transfers still require the special interop flag however).

 

I may roll-back our gateway and see if changing the network config media bypass setting fixes things? it's certainly useful to be aware of all of these thigns as it will likely raise its head again sometime.

 

Thanks again for your reply, it was very helpful, and very much appreciated.

 

Cheers!

Nat

Message 10 of 12