Fax / Modem Calls - Cisco UC500 series Configuration Manual

e. Configure transcoding profile and allow specific codecs
dspfarm profile 2 transcode
no codec ilbc
no codec g723r63
no codec g723r53
no codec gsmamr-nb
no codec g729br8
maximum sessions 6
associate application SCCP
no shut
f. Register the transcoder to the UC500
telephony-service
sdspfarm units 3
sdspfarm tag 2 mtp001b8fa84282
sdspfarm transcode sessions 6
sdspfarm unregister force

4.4.4 Fax / Modem Calls

The UC500 can support Fax calls via T.38 (SIP re-Invite) or pass-through (G.711 SIP re-
Invite) over the SIP trunk.
4.4.4.1 If the SP only supports T.38 – then the below changes need to be made to
enable this to work:
• Delete the FXS port where the fax machine is connected from the CCA interface.
• In the CLI – remove sccp configuration for the FXS port in question (in this example
using port 0/0/0):
dial-peer voice 1 pots
no service Remove SCCP control
destination-pattern 4085551010
• Enable T.38 support globally:
voice service voip
fax protocol t38
• Add T.38 support on the inbound & outbound SIP trunk dial-peers (note there may be
more than just 1000 shown below)
dial-peer voice 1000 voip
fax protocol t38
4.4.4.2 If the SP supports fax and modem via G.711 passthrough, then this should
work without any changes if the VOIP codec is G.711. If the VOIP Codec is G.729,
then UC500 can be configured such that only fax calls use G711 codec and VOIP
calls use G.729. Assume in this case the fax is on FXS port 0/0/0 which is extension
301 and this is mapped to PSTN DID 4085551010.
voice service voip
fax protocol none
no fax-relay sg3-to-g3
!
dial-peer cor list call-fax
member PSTN-fax
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Fax DID or PSTN number