[Home]

Summary:ASTERISK-17073: Regression - T.38 no longer functions
Reporter:Scott Johnson (globalnetinc)Labels:
Date Opened:2010-12-06 21:43:27.000-0600Date Closed:2011-09-14 08:52:59
Priority:MajorRegression?No
Status:Closed/CompleteComponents:Channels/chan_sip/T.38
Versions:Frequency of
Occurrence
Related
Issues:
Environment:Attachments:( 0) debug.zip
Description:Fax calls fail.  Modems never acan complete the trin.

maxdatagram is ignored

t38pt_udptl=yes,redundancy,maxdatagram=200

is set in the sip.conf file the peers

this is the invite from the ATA
INVITE sip:8884732963@172.16.0.4:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.255.2:5060;branch=z9hG4bK-5e239d89;rport
From: The Johnson Company <sip:4065877430@172.16.0.4>;tag=dc054a6d8968ca5bo1
To: <sip:8884732963@172.16.0.4>;tag=as78c8bd8c
Remote-Party-ID: The Johnson Company <sip:4065877430@172.16.0.4>;screen=yes;party=calling
Call-ID: 5f8ff155-63701093@192.168.255.2
CSeq: 103 INVITE
Max-Forwards: 70
Authorization: Digest username="4065877430",realm="asterisk",nonce="2a864f78",uri="sip:8884732963@172.16.0.4:5060",algorithm=MD5,response="68727e467a7265f353f4528567397463"
Contact: The Johnson Company <sip:4065877430@172.16.0.59:5060>
Expires: 30
User-Agent: Linksys/SPA2102-5.2.10
Content-Length: 265
Content-Type: application/sdp

v=0
o=- 2664756 2664756 IN IP4 172.16.0.59
s=-
c=IN IP4 172.16.0.59
t=0 0
m=image 16446 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxBuffer:200
a=T38FaxMaxDatagram:200
a=T38FaxUdpEC:t38UDPRedundancy


Here is what comes out of Asterisk to the trunk provider

INVITE sip:18884732963@66.62.196.101:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 216.166.168.4:5060;branch=z9hG4bK2ba7f248
Max-Forwards: 70
From: "The Johnson Company" <sip:4065877430@216.166.168.4>;tag=as1474ad27
To: <sip:18884732963@66.62.196.101>;tag=f51b80c154cc3e34cc79c473e7e19ed1
Contact: <sip:4065877430@216.166.168.4:5060>
Call-ID: 2119ea362e8f33da1e22c71623993b59@216.166.168.4:5060
CSeq: 103 INVITE
User-Agent: Asterisk PBX
Require: timer
Session-Expires: 1800;refresher=uac
Min-SE: 90
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH
Supported: replaces, timer
X-asterisk-Info: SIP re-invite (External RTP bridge)
Remote-Party-ID: "The Johnson Company" <sip:4065877430@216.166.168.4>;party=calling;privacy=off;screen=no
Content-Type: application/sdp
Content-Length: 266

v=0
o=root 1572151211 1572151212 IN IP4 216.166.168.4
s=Asterisk PBX
c=IN IP4 216.166.168.4
t=0 0
m=image 14370 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxDatagram:788
a=T38FaxUdpEC:t38UDPRedundancy
Comments:By: Scott Johnson (globalnetinc) 2010-12-07 22:41:24.000-0600

Try again to describe it. This time not late at night so I can truely type.  Modems go through the entire process trying to train on a baud rate then give up.  Also the maxdatagram is ignored.  This has run in the past with pre 1.8.0 release and 1.6.2.9.


By: Scott Johnson (globalnetinc) 2010-12-20 15:59:27.000-0600

What needs to be done so this can be looked at?  No FAX is an issue.  If there is something that has not been provided please let me know.
By: Matthew Nicholson (mnicholson) 2011-07-26 14:40:17.917-0500

The maxdatagram setting that asterisk sends is not configurable. The maxdatagram setting in the sip.conf configuration file is used to override datagram values received from remote hosts that are too small.

Why do you think your failures are caused by maxdatagram problems?

Also the maxdatagram parameter in the SDP packets indicate to the remote host what the sending peer is able to receive, not what the sending peer will be sending.
By: Leif Madsen (lmadsen) 2011-08-11 13:17:10.144-0500

Assigned to reported to provide feedback as requested.
By: Leif Madsen (lmadsen) 2011-09-14 08:52:54.953-0500

Suspended due to lack of activity. Please request a bug marshal in #asterisk-bugs on the IRC network irc.freenode.net to reopen the issue should you have the additional information requested.  Further information can be found at http://www.asterisk.org/developers/bug-guidelines