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Soundpoint 501 Dropping Calls

Occasional Contributor

Soundpoint 501 Dropping Calls

I have a soundpoint ip 501 at three remote locations that register to a talkswitch 484 VS.  The phones register to the talkswitch ,get their configs from the talkswitch and even register that they have missed calls.  However, when i call the extension or attempt to call out the phone will ring but when i pick up i get silence and then after a few seconds the call drops out. 


I'm trying to figure out where to look for the issue.  Is it on the talkswitch or the phone?  Have any of you seen this issue before?


Thanks for your help.



Message 1 of 3
Occasional Contributor

Re: Soundpoint 501 Dropping Calls

Just an added note.  It appears that the problem is tracing back to SIP.  My talkswitch pbx registers the phones but it appears that although SIP is permitted through the firewall that the phones cannot get through.  Could it be a setting on the phone it itself?  Again still trying to trace back if this is the phone or the pbx. I'm pretty sure i've removed the firewall out of the equation.



Message 2 of 3
Polycom Employee & Community Manager

Re: Soundpoint 501 Dropping Calls

Hello sbrousse,


you are mixing things up here and I would point you back to check the Firewall.


SIP is a signaling protocol (SOURCE) and is used to setup the call via SIP Messages usually on port 5060


Once the Call is established the Audio is transmitted via SDP on a separate Port.


If that Port is not allowed in your Firewall the Audio cannot pass between the Phone and the PABX.


Please liaise with an IT Specialist or check the Firewall and contact your local Polycom Reseller for further support.


Best Regards


Steffen Baier 



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