Avaya 1110 Fundamentals page 375

unique class identifier and requested network configuration and Connect Server parameters
for automatic configuration.
IP Deskphone class identifier
The IP Deskphone is designed with a unique class identifier that the DHCP server can use to
identify the telephone. All IP Deskphones use the text string Nortel-i2004-A or Nortel-i2004-B.
The ASCII string is sent inside the Class Identifier option of the IP Deskphone DHCP
messages.
The DHCP server also includes the string in its responses to the IP Deskphone DHCP client.
This makes it possible to notify the IP Deskphone that the server is IP Deskphone-aware, and
that it is safe to accept the server's offer. This string appears in the beginning of a list of specific
Call Server or TPS information that the IP Deskphone DHCP client requests.
When the DHCP server is configured to recognize the IP Deskphone as a special class, the
DHCP server can treat the IP Deskphone differently than other DHCP clients. DHCP host
configuration parameters can then be grouped by class to supply only information relevant to
the IP Deskphone DHCP client, such as the Connect Server parameters. The administrator
can also design the network according to the client's class, if necessary, making maintenance
easier.
Depending on the capabilities and limitations of the DHCP server used and the design of the
network, some of these advanced functions are not available.
Requested network configuration parameters
In full DHCP mode, an IP Deskphone-aware DHCP server can automatically configure IP
Deskphones by requesting a list of Connect Server configuration parameters. The IP
Deskphone uses DHCP to request and receive the information.
Table 75: IP Deskphone network configuration parameters
configuration parameters requested by the IP Phone in the Parameter Request List option
(Option Code 55) in the DHCPDISCOVER and DHCPREQUEST messages. The
DHCPOFFER and the DHCPACK reply messages from the DHCP server must contain the
options in Table 75: IP Deskphone network configuration parameters
Table 75: IP Deskphone network configuration parameters
Parameters requested by IP Deskphone (Option Code 55)
Subnet mask — the client IP subnet mask
Router/gateway(s) — the client default gateway IP address (not
required in DHCPOFFER in IP Deskphone Firmware 1.25 and
later for compatibility with Novell DHCP server)
DNS Server IP
DNS domain
Lease time — implementation varies according to DHCP server
IP Deskphones Fundamentals
Network features
on page 375 lists the network
on page 375.
DHCP server response:
Option Code
1
3
6
15
51
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