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VVX 501 phones dropping outbound calls

VAVoipTech
Occasional Contributor

VVX 501 phones dropping outbound calls

We run a hosted platform with our Polycom phones. We have over 1000 phones deployed at several locations, but only one customer is having this issue. We are the carrier also, providing dialtone via a SIP server.

 

The site is using VVX501 phones with 5.8.2 firmware. We were on 6.2.0 but rolled the firmware back hoping it may help the issue......it didn't.

 

Inbound calls work fine. No issues. When a call is placed outbound, usually a long distance 9+1+(number), the call will last 2 minutes or so and then, on the polycom side, you will lose audio. The screen never changes, there is no indication the call is gone other than lost audio. On the receiving side of that conversation, the phone hangs up on the caller. 

 

After call captures and wiresharks, we determined that around the 2 minutes mark, our SIP server sends an '100 info' message to the phone. The phone responds with '481 transaction does not exist'. The server then sends a 'BYE' to the phone. The phone responds again with '481 Transaction does not exist'. So our server sends a 'BYE' to the recieving side and tears down the call. A 'BYE' is send to the polycom as well, but the polycom never responds to the 'BYE'  and doesn't disconnect the call.

 

We have upgraded, downgraded phones, switched out the firewall, triple checked the circuit, changed switch ports, changed phones, swapped phones, defaulted and reprovisioned phones. We are out of options on a physical troubleshooting sense. The customer reported this problem on 1 phone, but as time has gone on, the problem seems to be with all phones and it is very intermittent. We are working to get contracts on the phones so Polycom Tech Support can look into it. Does anyone have any clues, ideas, hail mary passes they could suggest?

Message 1 of 4
3 REPLIES 3
SteffenBaierUK
Polycom Employee & Community Manager

Re: VVX 501 phones dropping outbound calls

Hello @VAVoipTech ,

 

Welcome to the Poly Community.

From our FAQ:

 

Jan 19, 2012 Question: How to troubleshoot Polycom VoIP related Issues?

Resolution: Please check => here <=

 

As you are a service provider you may already familiar with how to look at the logs


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

Best Regards

Steffen Baier

----------------
The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.

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Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 2 of 4
VAVoipTech
Occasional Contributor

Re: VVX 501 phones dropping outbound calls

We have looked at the Wireshark logs. I am waiting to go onsite once we can secure a service contract with Polycom before I look at Polycom logs. The guide is helpful in collecting information. But as we already have collected logs and wiresharks from our SIP server and the customer site, we still need to know what is causing the problem. We understand that the phones seem to be losing the call when they send the '481' message. But what is causing this message to be sent? And out of all the phones we have deployed over our service area, why is this customer the only one experiencing problems?
Message 3 of 4
SteffenBaierUK
Polycom Employee & Community Manager

Re: VVX 501 phones dropping outbound calls

Hello @VAVoipTech ,

 

Well, it should be pretty simple to set up logs on the phone end to understand how we see the call and check the signaling, etc. This way you are prepared and have data to supply to us via our support organization and/or spot the issue and correct it .

 

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

Best Regards

Steffen Baier

----------------
The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.

----------------

Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 4 of 4