CME to CME - phone rings but silence on pick up

[ianmair3291]

Hi there,

I have two routers with CME. They are both linked together via Ethernet.

I have 10 phones connected to each router. Making calls between 2 phones on same router is working fine.

I have set up dial peers and can place a call from a phone on router1 to a phone on router2. The phone rings fine but when I pick it up there is silence, I cannot hear audio between calls. When I hang up one phone the other one cuts off, so call setup seems to be working great.

I will post config tomorrow but wondered if there is a straightforward reason for this. Is it a codec issue?

Many thanks

[Chris Deren]

Are all the phones on the same VLAN? If not make sure you have proper IP routing between the VLANs.

Chris

[ianmair3291]

Hi Chris,

All phones on same vlan and subnet

Thanks

Ian

[Jorge Armijo]

Hi Ian,

What protocol are you using between the 2 cme's? H323 or SIP? Can you post the show version from each router. Also, what do you see if you hit "?" mark twice on the phone when the call is connected? Are the RX/TX packets incrementing?

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[Roger Kallberg]

Sound like the phones can't setup the RTP streams that goes directly between the endpoints (phones) when the call is setup. The signaling that goes from/to GW and phone seems to work, that's why the call is ringing and hangs up when the far ends disconnects the call.

Are you sure that the phones hanging off the two GWs can communicate directly with each other?

The RTP steams will be setup like this

Phone 1 (on GW 1) <> GW 1 <> GW 2 <--> Phone 1 (on GW 2)

And the signaling will be setup like this.

Phone 1 (on GW 1) <> GW 1 <> GW 2

GW 1 <> GW 2 <> Phone 1 (on GW 2)

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[ianmair3291]

I have fixed this issue. I had "no ip routing" set in my config.

Changed to "ip routing" and it works!

Thanks for the help though