Hi Anthony,
I got successful transmission working.  
I'm testing like this:
Fax Machine --> Linksys SPA-3102 --t.38-- > FS1 --audio --> FS2 (rxfax)
In analyzing the logs its seems FS2 was reporting the ECM was negotiated where the t38 side from was negotiating ECM off because the Linksys adapter doesn't do ECM.  By explicitly disabling ECM on the receiving end (FS2) everything is working.  Should it not negotiate ECM off all the way through?

Also, I'm still seeing late re-invites so I tried to do:
<action application="set" data="execute_on_answer=t38_gateway self nocng"/>

That fails with:
2012-12-21 17:00:19.617866 [WARNING] mod_spandsp_fax.c:1578 sofia/default/1002@10.59.1.195 Cannot locate channel with uuid f4b7afd8-4bd2-11e2-b9db-2fac9796034a

I took a look at mod_spandsp.c and can find any reason why that wouldn't work.  Am I missing something or should I file a jira?  The strange thing is that I use nocng with sip_execute_on_image and it works fine.


On Dec 21, 2012, at 2:34 PM, Anthony Minessale wrote:

if you dont need actual detection you can skip it with nocng and jump right into the processing,  
You'll have to eyeball it but it should detect it right away, take note of it by watching the logs.



On Fri, Dec 21, 2012 at 4:22 PM, Spencer Thomason <spencer@5ninesolutions.com> wrote:
I tried tweaking this and it didn't seem to have any effect.  I'm calling t38_gateway like this:
<action application="set" data="execute_on_answer=t38_gateway self"/>
before the bridge.

Is there anything I should be doing to speed up the detection?  I should note that is on the receiving end.

The re-invite from rxfax worked without a hitch.  Would this suggest the default req_counter value is ok?


On Dec 21, 2012, at 9:12 AM, Anthony Minessale wrote:

you can tweak mod_spandsp_fax.c:1391

req_counter is how many packets to wait before sending re-invite.

You can play with reducing this number and if its effective it could be made into a configurable param.



On Fri, Dec 21, 2012 at 10:42 AM, Spencer Thomason <spencer@5ninesolutions.com> wrote:
Hi Steve,
That was my take as well.   I've posted packet captures and logs here:
http://jira.freeswitch.org/browse/FS-4957

Is there any way to speed up the ReINVITE?

Thanks,
Spencer


-----Original message-----
From: Steve Underwood <steveu@coppice.org>
To: freeswitch-users@lists.freeswitch.org
Sent: Fri, Dec 21, 2012 09:57:07 GMT+00:00
Subject: Re: [Freeswitch-users] t.38 Call Flow Information

Hi,

It looks like your reinvite occurred extremely late, and the FAX was
already deep in progress as an audio exchange.

Steve


On 12/21/2012 03:14 AM, Spencer Thomason wrote:
> Hello,
> I've been analyzing some Wireshark traces to get a better grasp on the t.38 gateway process. I'm using t38_gateway to convert SIP t38 to TDM audio on the receiving end. I'm struggling to understand the following call flow. I've excluded the audio portion for brevity but t38 is negotiated correctly by both endpoints (FS on our end and Acme on the other). Note the absence of a DIS message and the PPS prior to CFR. Can anyone shed any light on this?
>
> Thanks in advance,
> Spencer
>
>
> Acme FreeSWITCH
> |1716.691635| INVITE SDP (t38) | |SIP Request
> | |(5060) <------------------ (5070) | |
> |1716.719556| 100 trying -- your call is important to us | |SIP Status
> | |(5060) ------------------> (5070) | |
> |1716.830431| | no-signal | |t38:t30 Ind:no-signal
> | | |(21440) <------------------ (15876) |
> |1716.906132| 200 OK SDP (t38) | |SIP Status
> | |(5060) ------------------> (5070) | |
> |1716.912839| ACK | | |SIP Request
> | |(5060) <------------------ (5070) | |
> |1716.973011| | no-signal | |t38:t30 Ind:no-signal
> | | |(21440) ------------------> (15876) |
> |1717.450595| | v21-preamble |t38:t30 Ind:v21-preamble
> | | |(21440) <------------------ (15876) |
> |1717.730869| | PPS | |t38:v21:HDLC:Partial Page Signal
> | | |(21440) <------------------ (15876) |
> |1717.780811| | no-signal | |t38:t30 Ind:no-signal
> | | |(21440) <------------------ (15876) |
> |1718.130798| | v17-14400-long-training |t38:t30 Ind:v17-14400-long-training
> | | |(21440) <------------------ (15876) |
> |1719.541095| | t4-non-ecm-data:v17-14400 |t38:t4-non-ecm-data:v17-14400 Duration: 1.51s No packet lost
> | | |(21440) <------------------ (15876) |
> |1721.060850| | no-signal | |t38:t30 Ind:no-signal
> | | |(21440) <------------------ (15876) |
> |1722.573572| | v21-preamble |t38:t30 Ind:v21-preamble
> | | |(21440) ------------------> (15876) |
> |1723.593652| | CFR | |t38:v21:HDLC:Confirmation To Receive
> _________________________________________________________________________
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> consulting@freeswitch.org
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>
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_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
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http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
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http://www.freeswitch.org


_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
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--
Anthony Minessale II

FreeSWITCH http://www.freeswitch.org/
ClueCon http://www.cluecon.com/
Twitter: http://twitter.com/FreeSWITCH_wire

AIM: anthm
MSN:anthony_minessale@hotmail.com
GTALK/JABBER/PAYPAL:anthony.minessale@gmail.com
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FreeSWITCH Developer Conference
sip:888@conference.freeswitch.org
googletalk:conf+888@conference.freeswitch.org
pstn:+19193869900
_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
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UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org


_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org




--
Anthony Minessale II

FreeSWITCH http://www.freeswitch.org/
ClueCon http://www.cluecon.com/
Twitter: http://twitter.com/FreeSWITCH_wire

AIM: anthm
MSN:anthony_minessale@hotmail.com
GTALK/JABBER/PAYPAL:anthony.minessale@gmail.com
IRC: irc.freenode.net #freeswitch

FreeSWITCH Developer Conference
sip:888@conference.freeswitch.org
googletalk:conf+888@conference.freeswitch.org
pstn:+19193869900
_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org