Outbound calling issue from analog lines

[jchristman2002]

We have an AX controller with 4 24 port boards in it with 88ish analog lines.  The system is using NexVortex SIP trunks. We can call from the desk sets (6930s) with out any issues but when we call from the analog lines if the call goes outside of the NexVortex system we get a busy not available. 

We opened a ticket with NexVortex and we were told their outbound gateway is rejecting the calls. They asked us first to set the codec to only G.711u which I did in the SIP Peer Profile. Nothing changed. They then said they saw a SDP Media error in the invite "m=image 0 udptl 0" and asked if we could remove the media attribute from the SDP. I haven't located a setting for this but I am not sure I am looking in the right place. 

It is odd that this only happens on the analog extensions and not from the desk phones.  Another install which is almost identical does not have any issues and the only difference is that it is an CX II controller with only a handful of analog extensions. 

[jchristman2002]

This is what I am getting from NexVortex.

The issue at hand remains the SDP offering from the Cisco. I looked at the last outbound attempt, and it is still sending an invalid media mapping via the m= header. See the example below:

2022-11-22 12:54:25 -0500 : 147.0.29.51:5060 -> 104.219.163.73:5060
INVITE sip:xxxxxxxxxx@nexvortex.com:5060;transport=UDP SIP/2.0
Contact: "Fax #2"<sip:xxxxxxxxxxx@XXX.xx.xx.xx:5060;transport=UDP>
To: <sip:xxxxxxxxxx@nexvortex.com>
From: "Fax #2"<sip:xxxxxxxxxxx@xxx.xx.xx.xx:5060>;tag=0_3705435581-798620795
Call-ID: 3705434516-798620793X
CSeq: 1 INVITE
Session-Expires: 90;Refresher=uas
Min-SE: 90
User-Agent: Mitel-3300-ICP 20.4.1.34 Mitel Border GW(MBG/11.4.0.247 TUG/4.15.0.155-01)
P-Asserted-Identity: "Fax #2"<sip:xxxxxxxxxxx@xxx.xx.xx.xx:5060;transport=UDP>


v=0
o=- 6437 6437 IN IP4 xxx.xx.xx.xx
s=NSTREAMING
c=IN IP4 xxx.xx.xx.xx
t=0 0
m=audio 20212 RTP/AVP 0 8 18 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
m=image 0 udptl 0
a=rtpmap:0 PCMU/8000



m=image 0 udptl 0 is not a valid media mapping supported by any of the upstream carriers networks we have tried to route to.
It doesn't appear to be valid per the RFC either. Can you send calls without this image codec mapping?

[jchristman2002]

We have discovered the issue is when the COS for the faxes (4) has FAX capable set to yet the phones.   This COS was a direct copy of the Phones COS  (2) with only the FAX capable setting causing the dial out failure.

[johnp]

That relates to T.38