Format Of The Ip Phone 2004 Terminal Dhcp Class Identifier Field; Format Of The Ip Phone 2004 Terminal Dhcp Encapsulated Vendor Specific Option - Avaya Communication Server 1000 Installation And Commissioning Manual

Troubleshooting WLAN IP Telephony installations
The IP Phone 2004 requires a default router to function.
• a Subnet Mask option
• a Vendor Specific option
OR
a Site Specific option
The initial DHCP implementation required only the Vendor Specific encapsulated
suboption. In interop testing with WinNT (up to SR4), it was discovered that WinNT does
not properly adhere to RFC 1541. As a result, it is not possible to use this option. The
implementation was changed to add support for either Vendor Specific subops or Site
Specific options. This new extension is tested and verified to work with WinNT.
The site-specific options are all DHCP options between 128 (0x80) and 254 (0xFE). These
options are reserved for site specific use by the DHCP RFCs.

Format of the IP Phone 2004 Terminal DHCP Class Identifier field

All IP Phone 2004 terminals fill in the Class ID field of the DHCP Discovery and Request
messages with Nortel-i2004-A:
• ASCII-encoded, NULL (0x00) terminated
• unique to IP Phone 2004
• –A uniquely identifies this version
Format of the IP Phone 2004 Terminal DHCP Encapsulated Vendor
Specific option
The following definition describes the IP Phone 2004 specific, Encapsulated Vendor Specific
option. This option must be encapsulated in a DHCP Vendor Specific option (Refer to RFC
1541 and RFC 1533) and returned by the DHCP server as part of each DHCP OFFER and
ACK message for the IP Phone 2004 to accept these messages as valid. The IP Phone 2004
pulls the relevant information out of this option and uses it to configure the primary and
(optionally) secondary TPSs. Either this encapsulated option or a similarly encoded site-
specific option must be present. Configure the DHCP server to send one or the other—but not
both. WinNT implementations must use the Site Specific option. For more information, see
DHCP support for handsets that emulate the IP Phone 2004
The format of the Encapsulated Vendor Specific option field is: Type, Length, Data.
• Type (1 octet): 5 choices: 0x80, 0x90, 0x9d, 0xbf, 0xfb (128, 144, 157, 191, 251)
224 Avaya WLAN IP Telephony Installation and Commissioning
on page 223.
November 2010