3Com VCX V7111, Руководство пользователя

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3Com
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VCX V7111 VoIP Gateway User Guide
FaxTransportMode = 2 (Bypass)
V34ModemTransportType = 2 (Modem bypass)
V32ModemTransportType = 2
V23ModemTransportType = 2
V22ModemTransportType = 2
In this configuration, both T.30 and V.34 faxes work in Bypass mode.
Or
FaxTransportMode = 1 (Relay)
V34ModemTransportType = 2 (Modem bypass)
V32ModemTransportType = 2
V23ModemTransportType = 2
V22ModemTransportType = 2
In this configuration, T.30 fax uses T.38 Relay mode while V.34 fax uses Bypass mode.
Using Relay mode for both T.30 and V.34 faxes
In this scenario, V.34 fax machines are compelled to use their backward compatibility with
T.30 faxes; as a T.30 machine, the V.34 fax can use T.38 Relay mode.
See the following configuration:
FaxTransportMode = 1 (Relay)
V34ModemTransportType = 0 (Transparent)
V32ModemTransportType = 0
V23ModemTransportType = 0
V22ModemTransportType = 0
Both T.30 and V.34 faxes use T.38 Relay mode. This configuration forces the V.34 fax
machine to operate in the slower T.30 mode.
Supporting V.152 Implementation
The gateway supports the ITU-T recommendation V.152 (Procedures for Supporting Voice-
Band Data over IP Networks). Voice-band data (VBD) is the transport of modem, facsimile,
and text telephony signals over a voice channel of a packet network with a codec appropriate
for such signals.
For V.152 capability, the gateway supports T.38 as well as VBD codecs (that is, G.711 A-law
and G.711
μ -law). The selection of capabilities is performed using the coders table.
When in VBD mode for V.152 implementation, support is negotiated between the gateway
and the remote endpoint at the establishment of the call. During this time, initial exchange of
call capabilities is exchanged in the outgoing SDP. These capabilities include whether VBD