3Com MSR 50 Series, Руководство по настройке

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Voice Function Configuration 2239
capabilities, and call policies. The registration server sends the registration
information to the location server for storage.
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SIP endpoints can use the proxy server to set up calls. SIP endpoints send
signaling messages to the proxy server and then the proxy server forwards
them to the next hop. In this process, multiple proxy servers may be involved.
Eventually, channels are established to transfer the upper layer voice service.
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Unlike the proxy server, the SIP redirect server will not forward the received
session request messages, but inform the originating SIP endpoints of the
addresses of the terminating SIP endpoints by returning reply messages. The
originating SIP endpoints directly re-originate a session request message to the
terminating SIP endpoints. The terminating SIP endpoints also directly return a
reply message to the originating SIP endpoints.
As a SIP endpoint, the voice router needs to exchange information with the servers
to accomplish the functions such as registration. For detailed configurations, refer
to
“SIP Overview” on page 2367 .
3
Fax protocol
Fax over IP (FoIP) complies with ITU-T T.30 and T.4 on PSTN and T.38 on the IP
network.
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T.30 defines the procedures necessary for document transmission between
facsimile terminals on PSTN. It gives detailed descriptions and stipulations on
the communication process, signal format, control signaling, and error
correction of Group 3 facsimile terminals on the general switched telephone
network.
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T.4 is a standard protocol used for document transmission between Group 3
facsimile terminals. It standardizes image coding, signaling modulation, rate,
transmission time, error correction, and document transmission of Group 3
facsimile terminals.
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T.38 describes the technical features necessary to transfer facsimile document
in realtime between Group 3 facsimile terminals over the Internet or other
networks by using IP protocols. It gives descriptions and stipulations on
communication mode, message format, error correction, and part of
communication processes.
Before applying the fax service, you need to configure the technical protocols and
physical characteristics. For detailed configurations, refer to
“Fax over IP
Configuration” on page 2343 .
Dial Plan Dial plan configuration is to provide diversified number management functions.
Dial plan configuration involves number substitution and number application.
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Number substitution means establishing some substitution rules and applying
them to calling and called numbers. Number substitution includes number
substitution rules and binding of number substitution rules.
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Number application means matching numbers, controlling the sending of
numbers, and selecting voice entities according to match templates. Number
application includes number match policy, rules in the match order for voice
entity selection, maximum-call-connection set, and number sending mode.