Help with SIP one way voice - will Cisco Router solve issue?

[J_Vansen_S]

hi All,

We have subscribed to a SIP provider(Inmarsat). We are supplied with a sip hardphone for voice calls.

We have 5 sip client hardphones connected to an "off-the-shelf" router.

It successfully registers to the SIP provider, but we are getting on way audio call.

We would like to propose a cisco router or ASA firewall, will it solve the issue of one-way audio?

If so what sort of feature are we looking at in the router/firewall

appreciate any advise

[Leo Laohoo]

One way call is a mostly caused by an invalid NAT entry.  

[J_Vansen_S]

is there any cisco product/features that can solve that?

[Leo Laohoo]

No.  This means that your NAT is configured incorrectly.  Throwing money is not a solution.  You'll need to work with your VSP to figure out where your NAT problem lies and fix it.

[J_Vansen_S]

Thanks for the info.

We are going to replace it with a cisco router anyways. Do we just do the normal dynamic PAT on the router? We cant do a static 1-1 nat as we have several of the SIP phones

[Leo Laohoo]

What you are doing is inefficient.  

It is better to configure a call server box, like Cisco CUCM.  

All your phones talk to your call server and your call server talks to your VSP.    What you are planning is all your phones talk to your VSP.  That's inefficient.