Hello Everyone,
I am sending outbound fax to fax provider and when the provider send RE-INVITE ( transmit data ) it offer T38 udptl, but SEMS rejects with 488. I can provide call trace privately .
Yeti version 1.11
INVITE from provider
2023/10/03 13:35:57.974705:5080 ->:5060
INVITE sip::5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 8.34.182.111:5080;branch=z9hG4bK-524287-1---9b087fbf44801de94df283fd6a85677f;rport
Via: SIP/2.0/UDP :5060;branch=z9hG4bK-524287-1---13d5ffd89c8104fbc2f2016c90ed8778;rport=5060
Via: SIP/2.0/UDP :5071;rport=5071;branch=z9hG4bK-b5voq24mkgxgokis
Max-Forwards: 68
Contact: sip::5071
To: "AustenTel" <sip:@>;tag=8-59FD04B6-651C5F0B00080D9D-89165700
From: <sip:18553922666@sip.t38fax.com:5080>;tag=BAKFZOQTXIAWGLV5NFNA____.i
Call-ID: 8-0BF19C75-651C5F0B00080D9F-89165700
CSeq: 338 INVITE
Expires: 300
Allow: INVITE, ACK, BYE, CANCEL, INFO, SUBSCRIBE, NOTIFY, REFER, MESSAGE, OPTIONS, UPDATE
Content-Disposition: session
Content-Type: application/sdp
User-Agent: PortaSIP
cisco-GUID: 3225567282-2229990007-75036265-2395768298
h323-conf-id: 3225567282-2229990007-75036265-2395768298
Content-Length: 308
v=0
o=PortaSIP 2253496717237690269 2 IN IP4
s=T38FAX
t=0 0
m=image 28752 udptl t38
c=IN IP4
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxFillBitRemoval
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxBuffer:2000
a=T38FaxMaxDatagram:400
a=T38FaxUdpEC:t38UDPRedundancy