[Freeswitch-users] T38 unsuccessful: result (48) Disconnected after permitted retries

Tue Jun 15 10:17:48 PDT 2010

Hi,

That png looks like an RTP packet being interpreted as if it were UDPTL. 
This is quite normal during switchover, as the two ends never switch at 
the same moment. If you see nothing arriving after those three packets, 
it looks like no T.38 packets arrive at all.

Steve

On 06/15/2010 11:41 PM, samuel wrote:
> I got a pcap file and after the T.38 renegotiation, wireshark reports 
> T.38 Malformed packet from the "originator" A.B.C.D. It sends 3 of 
> these packets and then stops. From freeswitch I just see "Unknown RTP 
> version 0" packets going to A.B.C.D
>
> I attach a png containing the wireshark malformed packet 
> "capture"..apologies in advanced but it's a few Kb and it's the 
> fastest way not to replace all "sensitive" information (IPs, 
> hostnames,etc...). Hope it passes the list filter..
>
>
> On 15 June 2010 17:12, Anthony Minessale <anthony.minessale at gmail.com 
> <mailto:anthony.minessale at gmail.com>> wrote:
>
>     did you watch it in a pcap?
>     Maybe it's one way audio.
>
>
>
>     On Tue, Jun 15, 2010 at 7:03 AM, samuel <samu60 at gmail.com
>     <mailto:samu60 at gmail.com>> wrote:
>
>         hi all,
>
>         recently testing T.38 unsuccesfully with freeswitch head
>         version (FreeSWITCH Version 1.0.head (git-) ) on a testing
>         server (2.6.26-2-xen-amd64)
>
>         remote SDP:
>
>         v=0
>         o=root 6039 6040 IN IP4 A.B.C.D
>         s=session
>         c=IN IP4 A.B.C.D
>         t=0 0
>         m=image 19423 udptl t38
>         a=T38FaxVersion:0
>         a=T38MaxBitRate:9600
>         a=T38FaxFillBitRemoval:0
>         a=T38FaxTranscodingMMR:0
>         a=T38FaxTranscodingJBIG:0
>         a=T38FaxRateManagement:transferredTCF
>         a=T38FaxMaxBuffer:72
>         a=T38FaxMaxDatagram:72
>         a=T38FaxUdpEC:t38UDPRedundancy
>
>         freeswitch answer:
>         v=0
>         o=FreeSWITCH 1276579579 1276579581 IN IP4 W.X.Y.Z
>         s=FreeSWITCH
>         c=IN IP4 W.X.Y.Z
>         t=0 0
>         m=image 22230 udptl t38
>         a=T38FaxVersion:0
>         a=T38MaxBitRate:14400
>         a=T38FaxFillBitRemoval
>         a=T38FaxRateManagement:transferredTCF
>         a=T38FaxMaxBuffer:2000
>         a=T38FaxMaxDatagram:400
>         a=T38FaxUdpEC:t38UDPRedundancy
>         a=T38VendorInfo:0 0 0
>
>
>         some debug:
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 T4 expired in phase T30_PHASE_B_RX, state 17
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Too many retries. Giving up.
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Changing from phase T30_PHASE_B_RX to T30_PHASE_D_TX
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.38T Set rx type 0
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.38T Set tx type 4
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Changing from state 17 to 3
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Tx:  DCN with final frame tag
>         2010-06-15 13:37:13.234961 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Tx:  ff 13 fa
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Send complete in phase T30_PHASE_D_TX, state 3
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Send complete in phase T30_PHASE_D_TX, state 3
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Disconnecting
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Changing from phase T30_PHASE_D_TX to T30_PHASE_E
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.38T Set rx type 0
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.38T Set tx type 1
>         2010-06-15 13:37:14.406960 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Changing from state 3 to 2
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:271 FLOW
>         T.30 Send complete in phase T30_PHASE_E, state 2
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:301
>         ==============================================================================
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:313 Fax
>         processing not successful - result (48) Disconnected after
>         permitted retries.
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:318
>         Remote station id:
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:319 Local
>         station id:  SpanDSP Fax Ident
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:320 Pages
>         transferred: 0
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:322 Total
>         fax pages:   0
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:323 Image
>         resolution:  0x0
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:324
>         Transfer Rate:     14400
>         2010-06-15 13:37:15.634931 [DEBUG] mod_spandsp_fax.c:326 ECM
>         status         off
>
>         I've starting learning about T3X and freswitch so I would like
>         whether someone can point me to any doc or any configuration
>         parameter that can solve the issue or at least debug it.
>
>         Thanks in advance,
>
>         Samuel
>