3Com VCX V7000, Руководство по установке и обслуживанию

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ERVER
Overview
RFC 2132 (DHCP Options and BOOTP Vendor Extensions) allows for
vendor-specific extensions to the DHCP protocol. It defines that option
codes in the range 128 through 254 are set aside for vendor-specific
extensions.
3Com telephones can receive their IP configuration from a DHCP server.
However, 3Com telephones need configuration information that is not
part of a standard DHCP response. You can use DHCP option 184 to
specify this extended information:
■
NCP IP Address — Each telephone must receive a download of
operating settings from the VCX Downloader task, which typically
resides on the same server as the VCX Network Call Processor (NCP).
■
Alternate Server IP Address — Specifies a second location from
which a telephone can receive its download. Typically, this is the IP
address of the other VCX NCP in a dual-server configuration.
■
Voice VLAN Configuration — If you configure any of your 3Com
telephones or your VCX system on Virtual LANs, you can configure
your DHCP server to specify VLAN ID numbers for each scope. You can
also enable and disable VLAN operation for each DHCP scope.
■
Fail-Over Call Route Point — You can define a single fail-over route
point (IP address) and an associated dial string for SIP devices such as
telephones to use.
If a failure occurs on the primary VCX NCP, the telephone switches to
the secondary VCX NCP. If both are unavailable, the telephone
switches to peer-to-peer SIP operation and attempts to connect to the
IP address of the fail-over route point. The dial string controls the
types of calls that can be made while the telephone is in peer-to-peer
mode.