Am trying to convert environment to T.38 faxing with passthrough as a fallback. One sticking point is an internal fax server solution, connected via a T1 crossover cable (Cisco 3845 router <-T1-> Windows Net Satisfaxtion Server). The problem I have is some VG224-connected fax machines are communicating with T.38 to the 3845 router, but then the router wants to communicate with T.38 out its PRI interface. in other words, it doesn't appear to be decoding the T.38 into G711. this is causing fax to fail, since the Net Satisfaxtion Server is not configured for T.38 on this non-IP PRI. Any other advice would be appreciated. thx in advance! The fundamental problem is obviously, im not good enough to configure it correctly. :) But im confused as to why the 3845 router would even think to send T.38 out a non-IP PRI.
fax <-> vg224 OGW <-> CUCM <-> 3845 TGW <-> Satisfaxtion Server
I have played around with the 3845 gateway in call manager, enable/disable t.38 option, but it still communicates with T.38. Doesn't seem like MGCP is smart enough to step down to G711. Also, I'm confused on the whether call manager communicates the fax to the 3845 or hands it off so 3845 communicates directly with VG224.
VG224:
voice service voip
allow-connections sip to sip
fax protocol t38 version 3 ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
dial-peer voice 102 voip ! internal dial peer - only g711ulaw
preference 1
destination-pattern 8.....
rtp payload-type comfort-noise 13
session protocol sipv2
session target ipv4:CiscoCM1
session transport tcp
dtmf-relay sip-notify cisco-rtp rtp-nte
codec g711ulaw
fax-relay ecm disable
fax nsf 000000
fax protocol pass-through g711ulaw ! internal dial peer - only g711ulaw
no vad
!
dial-peer voice 6 voip ! external dial peer - only T.38 & g711ulaw
preference 1
destination-pattern .T
rtp payload-type comfort-noise 13
session protocol sipv2
session target ipv4:CiscoCM1
session transport tcp
dtmf-relay sip-notify cisco-rtp rtp-nte
codec g711ulaw
fax-relay ecm disable
fax nsf 000000
no vad
3845 MGCP Router:
voice service voip ! not sure if I need this with MGCP router
fax protocol t38 version 3 ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
modem passthrough nse codec g711ulaw
!
mgcp
mgcp call-agent CiscoCM1 2427 service-type mgcp version 0.1
mgcp dtmf-relay voip codec all mode out-of-band
mgcp rtp unreachable timeout 1000 action notify
mgcp package-capability rtp-package
mgcp package-capability sst-package
mgcp package-capability pre-package
mgcp default-package fxr-package
no mgcp package-capability res-package
no mgcp timer receive-rtcp
mgcp sdp simple
mgcp fax t38 nsf 000000
mgcp rtp payload-type g726r16 static
mgcp bind control source-interface GigabitEthernet0/0
mgcp bind media source-interface GigabitEthernet0/0
