Forcing V.34 fax terminals to fallback to legacy G3 modulations over voice over intrnet protocol networks

Abstract

Gracefully forcing two V.34 fax devices to use legacy G3 modulations (e,g., V.21, V.27ter, V.29, V.17) when communicating over a packet network (e.g, voice over Internet Protocol (VoIP)network). To force an originating fax terminal 10 and receiving fax terminal 18 to fallback to legacy modulation procedures, transmission of a Call Menu (CM) “FAX” signal 54 transmitted by the originating fax device 10 is suppressed S38 at either the originating VoIP/FoIP gateway 12 or answering VoIP/FoIP gateway 16. The suppression of the CM signal 54 forces the answering V.34 fax device 18 to timeout and fallback to non-V.34 fax modulations S40 as if the calling terminal 10 was not V.34-capable. Likewise, upon detecting the non-V.34 fax signals, the originating V.34 fax device 10 will fallback to non-V.34 fax procedures S42. The two V.34 fax terminals will continue the fax transmission using non-V.34 modulations S44.

Dependencies are inferred from the claim text.