Hi Experts, I've an issue with Clear-Channel codec.
I've a SIP Trunk between an AS5400 HPX and a Cisco 1760. I would use this connection to manage ISDN data modem calls with 64 Kbit/s Unrestricted Digital Information capability.
This is the scenario:
PSTN ---> AS5400 HPX -----------> C1760 ----> ISDN DEVICES
When arrives a call from PSTN, the AS5400 sends a SIP INVITE to C1760 like this:
INVITE sip:****@10.25.100.77:5060 SIP/2.0
Record-Route: <sip:10.35.0.140;lr;ftag=845772525>
Via: SIP/2.0/UDP 10.35.0.140;branch=z9hG4bKc722.c8a3f237.0
Via: SIP/2.0/UDP 10.35.0.10:5060 ;branch=z9hG4bKterm-3da-59144
From: ****<sip:****@10.35.0.10;user=phone>;tag=845772525
To: ****<sip:****@****;user=phone>
Call-ID: 281a96d2-7e24ec0a-43ea514a-1b4@10.35.0.10
CSeq: 1 INVITE
Supported: timer
Session-Expires: 14400
Min-SE: 14400
Contact: <sip:****@10.35.0.10:5060>
Allow: INVITE,ACK,PRACK,SUBSCRIBE,BYE,CANCEL,NOTIFY,INFO,REFER,UPDATE
Max-Forwards: 9
Content-Type: application/sdp
Content-Length: 391
v=0
o=- 1446949 0 IN IP4 10.35.0.122
s=Cisco SDP 0
c=IN IP4 10.35.0.122
t=0 0
m=audio 16542 RTP/AVP 125 101 100
a=rtpmap:125 G.nX64/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194,200-202
a=X-sqn:0
a=X-cap: 1 audio RTP/AVP 100
a=X-cpar: a=rtpmap:100 X-NSE/8000
a=X-cpar: a=fmtp:100 192-194,200-202
a=X-cap: 2 image udptl t38
The call is rejected by C1760 for this reason:
SIP/2.0 488 Not Acceptable Media
Via: SIP/2.0/UDP 10.35.0.140;branch=z9hG4bKc722.c8a3f237.0,SIP/2.0/UDP 10.35.0.10:5060 ;branch=z9hG4bKterm-3da-59144
From: ****<sip:****@10.35.0.10;user=phone>;tag=845772525
To: ****<sip:****@****;user=phone>;tag=9D0542E-1395
Date: Fri, 08 Mar 2002 21:29:32 GMT
Call-ID: 281a96d2-7e24ec0a-43ea514a-1b4@10.35.0.10
Server: Cisco-SIPGateway/IOS-12.x
CSeq: 1 INVITE
Allow-Events: telephone-event
Content-Length: 0
I've noted that the SDP of C1760 uses a different format to indicate clear channel.
AS5400: a=rtpmap:125 G.nX64/8000
C1760: a=rtpmap:125 X-CCD/8000
Is this the issue?
Is there a way to internetworking the problem?
Thanks in advanced.
