Cisco Support Community
Community Member

Desperate for help with PAP2T Linksys

Hi There

I have a PAP2T here and a TG582n Modem

Looking to use Sonetel as a Voip provider. It all works fine on a DSL G604t modem, but with this one, theres only one way sound ( I cant hear the other person ) 

I have tried some port forwarding and all but I am so confused the problem still persists.


I posted some photos here. If someone can please help me, I'd really appreciate it


VIP Blue

One way audio is caused by

One way audio is caused by NAT/firewa//STUN misconfiguration in most cases. Bot PAP2T and your xDSL device needs to be configured in compatible way.

If you can hear no remote side, then icomming RTP stream either doesn't pass trough xDSL into internal network at all, or it such stream is translated an unexpected way so it's missed by PAP2T.


Catch the network communication between xDSL and PAP2T. If you will see no incomming RTP stream the xDSL configuration needs to be modified. If you will see a RTP stream, it's parameter together with catched SIP dialog packets may help you to narrow the issue ...



Community Member

You can also turn on SIP-alg

You can also turn on SIP-alg on the TG582n


or possibly port forward udp 5060-5080 and RTP ports found on the

sip-->RTP Parameters

 I think it's udp 16384 - 16482

to the address of the pap2t



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