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VOIP Audio issue external: Polycom

Occasional Visitor

VOIP Audio issue external: Polycom

The IP phones when connected to Home(Remote users) there is no audio.


We have a VoIP setup across our offices with a switchvox/digum box and Polycom IP phones.

The internal office communication and from office communication to the outside world is excellent.



We decided to give out the IP phones to remote/home users to plug into internet and could use it as inter office communication.

The problem here is when we connec the IP phones at home each pointing to the Server/Digum box external IP the communication doesnot happen:

 - Each phone is programmed manually with extention

 -When the Home phone dials an office extension the Phone rings in office as receiveing a call but there is no audio at all.


Some config explainations:

  The server/digum has a external IP configured on firewall to nat to the internal ip (our internal subnet)

   The Home/Remote IP phones are pointing to the server Public ip when connecting.

   The firewall has the below ports open for Voip and required policy applied:

     UDP:   5060,2234-2237, 4569, 10000-20000

     TCP: 5060,2000, 80,  443



Please advise if you need any more explaination and output. 




Message 1 of 2
Polycom Employee & Community Manager

Re: VOIP Audio issue external: Polycom

Hello PM,


welcome to the Polycom Community.


According to the Admin Guide:


The starting port for RTP packets. Ports will be allocated from a pool starting with this port up to a value of (startport + 47) for a voice-only phone or (start-port + 95) for a video phone.


So your Port 2234-2237 would not cover this.


Best Regards


Steffen Baier


Polycom Global Services

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 2 of 2