[asterisk-users] Fax over IP?

[Tim Nelson]

----- Original Message ----- 

> Hi Tim,

> I'm using Asterisk 10 and on Cisco GW the protocol is set for FAX is
> T.38 and when I try to send the fax from a fax machine i.e. HP 3180,
> I'm getting some warnings as listed below;

> -- Executing [4112345678 at default:1] Goto("SIP/192.168.1.69-00000005",
> "fax-detect,fax,1") in new stack
> -- Goto (fax-detect,fax,1)
> -- Executing [fax at fax-detect:1] NoOp("SIP/192.168.1.69-00000005",
> "**** FAX DETECTED ****") in new stack
> -- Executing [fax at fax-detect:2] Goto("SIP/192.168.1.69-00000005",
> "fax-receive,receive,1") in new stack
> -- Goto (fax-receive,receive,1)
> -- Executing [receive at fax-receive:1]
> NoOp("SIP/192.168.1.69-00000005", "**** FAX RECEIVE ****") in new
> stack
> -- Executing [receive at fax-receive:2] Set("SIP/192.168.1.69-00000005",
> "GLOBAL(FAXCOUNT)=5") in new stack
> == Setting global variable 'FAXCOUNT' to '5'
> -- Executing [receive at fax-receive:3] Set("SIP/192.168.1.69-00000005",
> "FAXCOUNT=5") in new stack
> -- Executing [receive at fax-receive:4] Set("SIP/192.168.1.69-00000005",
> "FAXFILE=fax-5-rx.tif") in new stack
> -- Executing [receive at fax-receive:5] Set("SIP/192.168.1.69-00000005",
> "GLOBAL(LASTFAXCALLERNUM)=6461234567") in new stack
> == Setting global variable 'LASTFAXCALLERNUM' to '6461234567'
> -- Executing [receive at fax-receive:6] Set("SIP/192.168.1.69-00000005",
> "GLOBAL(LASTFAXCALLERNAME)=") in new stack
> == Setting global variable 'LASTFAXCALLERNAME' to ''
> -- Executing [receive at fax-receive:7]
> NoOp("SIP/192.168.1.69-00000005", "**** SETTING FAXOPT ****") in new
> stack
> -- Executing [receive at fax-receive:8] Set("SIP/192.168.1.69-00000005",
> "FAXOPT(ecm)=yes") in new stack
> -- Executing [receive at fax-receive:9] Set("SIP/192.168.1.69-00000005",
> "FAXOPT(headerinfo)=MY FAXBACK RX") in new stack
> -- Executing [receive at fax-receive:10]
> Set("SIP/192.168.1.69-00000005",
> "FAXOPT(localstationid)=1234567890") in new stack
> -- Executing [receive at fax-receive:11]
> Set("SIP/192.168.1.69-00000005", "FAXOPT(maxrate)=14400") in new
> stack
> -- Executing [receive at fax-receive:12]
> Set("SIP/192.168.1.69-00000005", "FAXOPT(minrate)=2400") in new
> stack
> -- Executing [receive at fax-receive:13]
> NoOp("SIP/192.168.1.69-00000005", "FAXOPT(ecm) : yes") in new stack
> -- Executing [receive at fax-receive:14]
> NoOp("SIP/192.168.1.69-00000005", "FAXOPT(headerinfo) : MY FAXBACK
> RX") in new stack
> -- Executing [receive at fax-receive:15]
> NoOp("SIP/192.168.1.69-00000005", "FAXOPT(localstationid) :
> 1234567890") in new stack
> -- Executing [receive at fax-receive:16]
> NoOp("SIP/192.168.1.69-00000005", "FAXOPT(maxrate) : 14400") in new
> stack
> -- Executing [receive at fax-receive:17]
> NoOp("SIP/192.168.1.69-00000005", "FAXOPT(minrate) : 2400") in new
> stack
> -- Executing [receive at fax-receive:18]
> NoOp("SIP/192.168.1.69-00000005", "**** RECEIVING FAX : fax-5-rx.tif
> ****") in new stack
> -- Executing [receive at fax-receive:19]
> ReceiveFAX("SIP/192.168.1.69-00000005",
> "/var/spool/asterisk/fax/fax-5-rx.tif") in new stack
> -- Channel 'SIP/192.168.1.69-00000005' receiving FAX
> '/var/spool/asterisk/fax/fax-5-rx.tif'
> == Using UDPTL CoS mark 5
> [Jun 4 12:35:02] NOTICE[10371]: chan_sip.c:7577 sip_read: FAX CNG
> detected but no fax extension
> [Jun 4 12:35:02] WARNING[10072]: res_fax.c:1666 receivefax_t38_init:
> channel 'SIP/192.168.1.69-00000005' refused to negotiate T.38
> [Jun 4 12:35:02] WARNING[10072]: res_fax.c:1687 receivefax_t38_init:
> Audio FAX not allowed on channel 'SIP/192.168.1.69-00000005' and
> T.38 negotiation failed; aborting.
> [Jun 4 12:35:02] ERROR[10072]: res_fax.c:1891 receivefax_exec: error
> initializing channel 'SIP/192.168.1.69-00000005' in T.38 mode
> == Spawn extension (fax-receive, receive, 19) exited non-zero on
> 'SIP/192.168.1.69-00000005'

> In my sip.conf global configuration I enabled 'fax detect' and
> 't38pt_udptl' and added Cisco VGW peer;

> [CiscoVGW-10.70.X.X]
> host=10.70.X.X
> type=friend
> disallow=all
> allow=ulaw
> allow=alaw
> nat=yes
> insecure=port,invite
> context=fax-call
> canreinvite=no
> qualify=yes
> dtmfmode=inband


T.38 failed to negotiate. That means either your Asterisk side, or your Cisco side are not playing nicely together. A packet capture of the call setup would be helpful to determine which side is having the issues.

--Tim