Avaya 1110 Fundamentals page 376

Features
Parameters requested by IP Deskphone (Option Code 55)
Renewal time — implementation varies according to DHCP
server
Rebinding interval — implementation varies according to DHCP
server
TFTP Server Name
IP Line site-specific or vendor-specific encapsulated or site
options.
The first eight parameters in
page 375 are standard DHCP options and have pre-defined option codes. The last parameter
is for Call Server or TPS information, which do not have a standard DHCP option. The server
administrator must define a vendor-encapsulated or site-specific option or both to transport
this information to the IP Deskphone.
This non-standard information includes the unique string identifying the IP Deskphone and the
Connect Server parameters for the primary and secondary servers. The IP Deskphone must
receive the Connect Server parameters to connect to the IP Telephony node.
The administrator must use one of the site-specific or vendor-encapsulated option codes to
implement the Call Server or TPS information. This user-defined option can then be sent as-
is, or encapsulated in a Vendor Encapsulated option with Option Code 43. The method used
depends on the DHCP server's capabilities and what options are already in use by other
vendors.
The IP Deskphone rejects any DHCPOFFER and DHCPACK messages that do not contain
the following options:
• a router option — IP Deskphone requires a default gateway (router)
• a subnet mask option
• a vendor-specific option or a site-specific option
The vendor-specific option code is 43. A Windows NT DHCP Server (up to SR4) supports
only 16 octets of data for the vendor-specific option, which is insufficient to support the
minimum length of the IP Deskphone-specific string. If you use a Windows NT DHCP
Server, select the Site Specific option to accommodate the IP Deskphone-specific
string.
1
RFC 3942 states that DHCP site-specific options 128 to 223 are hereby reclassified as publicly defined options. The IP
Deskphone supports 9 vendor-specific options in this range and continues to do so for backward compatibility. However,
as suggested in RFC 3942, the use of these options is discouraged to avoid potential future collisions.
376 IP Deskphones Fundamentals
Table 75: IP Deskphone network configuration parameters
Comments? infodev@avaya.com
DHCP server response:
Option Code
58
59
66
43, Footnote., 131, 144,
157, 188, 191, 205,
219,Footnote., 224, 227,
230, 232, 235, 238, 241,
244, 247, 249, 251, and
254
1
February 2013
on