I seem to be going round in circles and would like some pointers.
We have a SIP provider connected via a VPN (so no SIP authentication), an 2811 acting as CUBE and CUCM 7 with SCCP phones and a SIP trunk to CUBE.
Voice Class Codec on CUBE with G729r8, G711Ulaw & G711Alaw preferenced in that order.
Inter-region CODEC between SIP trunk and Phones set to G729.
Route pattern on CUCM is doing all digit manipulation for outbound (striping predot) so full UK number sent to SIP provider.
Inbound calls work fine and connect at g729 regardless of the inter-region Codec (729 or 711), expected behavior.
Outbound is my problem. Call is routed, end phone rings (maybe) and the call is dropped...regardless of inter-region codec.
SIP tracing and debugging shows that on the 183 session progress sent by SIP provider, the gateway, or trunk sends a cancel with Q.850 disconnect 65 - The equipment sending this cause does not support the bearer capability requested.
In the CCSIP mess debugs you see the SDP message sent to provider and the codec requested is always G711Ulaw, regardless of inter-region codec and or contents of voice class codec.
so it appears to be media negotiation is at fault but i am at a loss to resolve this.
Not sure if i need MTP/Xcode resource so i have made both available on the CUCM to no avail (i think this is DTMF relay stuff, haven't tgot that far yet, plain voice would be nice!!). I have tied the codec down on the dialpeers even tried CODEC TRANSPARENT (even though docs say for h323 only), nothing.
Now for the funny, if I configure a gatekeeper controlled trunk on CUCM and configure the CUBE to register to GATEKEEPER and use the GK trunk for outbound calls it works with inter-region of G711, but again not with G729 although the failure this time is that teh call is dropped when remote end answers!!!!
So does anyone please have an idea of where i can look next, i can't be far off as inbound works
IOS is SPSERVICES 12.4.24.T1
A few things:
In CUCM 7.0, this was the first version that allowed outgoing SIP trunks to use G.729 with an MTP. It sounds like you don't have it enabled so you're doing delayed offer.
The suggestion is to use DO-EO conversion with CUBE with the 'early offer forced' configuration on the outgoing dial peer.
Then on your dial peer you can set the codec there. I would check a few things:
1) Codec g729r8 is higher on your voice class codec list
2) Your outgoing and incoming dial peers have the same voice class codec defined
You can also try 'codec transparent' on both dial peers. Note: you cannot use EO-DO with codec transparent.