Configuring the Cisco SPA8800 IP Telephony Gateway in an Asterisk Environment
© 2009 Cisco Systems, Inc. All rights reserved.
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T.38 Faxing
The SPA8800 supports fax with G.711 pass-through or real-time fax over IP via T.38 fax relay.
The only change from default setting for fax pass-through is to change from the default named
signaling event (NSE) to ReINVITE:
Web-ui > Voice tab > Line N tab > Audio Configuration > FAX Passthru Method: ReINVITE
Optionally, you can change the FAX Line Toggle code from the default of #99. Predialing #99 as a
prefix forces the call to be a fax call. This will case the INVITE to indicate T.38 in the SDP without
relying on a reINVITE to switch to T.38. The default can be changed from #99 with the
web-ui > Voice tab > Regional tab > Vertical Service Activation Codes > FAX Line Toggle Code:
Refer to the
