3Com MSR 50 Series, Руководство по настройке

Страница: 571 / 2443

Protocols and Standards 571
Figure 169 Sub-option 1 in verbose padding format
n
In the above figure, except that the VLAN ID field has a fixed length of 2 bytes, all
the other padding contents of sub-option 1 are length variable.
■
sub-option 2: Padded with the MAC address of the interface that received the
client’s request. It has the same format as that in normal padding format, as
shown in
Figure 168 .
Option 184
Option 184 is a reserved option, and parameters in the option can be defined as
needed. The device supports Option 184 carrying the voice related parameters, so
a DHCP client with voice functions can get an IP address along with specified voice
parameters from the DHCP server.
Option 184 involves the following sub-options:
■
Sub-option 1: IP address of the primary network calling processor, which is a
server serving as the network calling control source and providing program
downloads.
■
Sub-option 2: IP address of the backup network calling processor that DHCP
clients will contact when the primary one is unreachable.
■
Sub-option 3: Voice VLAN ID and the result whether DHCP clients take this ID
as the voice VLAN or not.
■
Sub-option 4: Failover route that specifies the destination IP address and the
called number (SIP users use such IP addresses and numbers to communicate
with each other) that a SIP user uses to reach another SIP user when both the
primary and backup calling processors are unreachable.
n
You must define sub-option 1 to make other sub-options take effect.
Protocols and
Standards
■
RFC2131:Dynamic Host Configuration Protocol
■
RFC2132:DHCP Options and BOOTP Vendor Extensions
■
RFC1542:Clarifications and Extensions for the Bootstrap Protocol
Sub-option type (0x01) Length Node identifier
Interface type Interface number
PVC identifier VLAN ID