Fax with Asterisk 1.8

#1

do i need to modify chan_sip for T.38 fax. i am able to send fax by using spandsp if i use G711, but T.38 fax gives me following error “error initializing channel ‘SIP/channel’ in T.38 mode” and FAXERROR has “T38_NEG_ERROR”. Do i need to get a license? i am using SIP trunk for fax call. please guide

#2

Did you enable T38 fax in sip.conf?

t38pt_udptl=yes,redundancy
faxdetect=yes
t38pt_udptl=yes
#3

yes i have

faxdetect=yes
t38pt_udptl=yes

but the error is T38_NEG_ERROR, which means i am not getting T.38 synched or provider is not sending on T.38

#4

What is your error correction setting? Default setting is FEC, but you can also set Redundancy. You have to ask your provider which type of redundancy its T.38 implementation supports.

#5

Yes you need to modify and correct all the mistakes and then only you will be able to correct all your mistakes and make the device working.