Introduction To Dhcp - Nortel Meridian ITG Line 2.0 Description, Installation And Operation Manual

Page 282 of 302

Introduction to DHCP

553-3001-204 Preliminary 0.10 August 2000
In order to understand how the i2004 Internet Telephone acquires the needed
network configuration parameters automatically, the following section
briefly describes the Dynamic Host Configuration Protocol (DHCP) protocol.
It is recommended that readers, unfamiliar with the subject, read this section.
Topics discussed will be helpful for the configuration and future maintenance
of the DHCP server and ensure correct implementation with the i2004
Internet Telephone.
DHCP is an extension of BootP. Like BootP, it operates on the client-server
model. Unlike BootP, DHCP has more message types. DHCP allows the
dynamic allocation of IP addresses to different clients. It can be used to
configure clients by supplying the network configuration parameters such as
gateway or router IP addresses.
In addition, DHCP has a lease system that controls the duration an IP address
is leased to a client. The client can request a specific lease length, or the
administrator can determine the maximum lease length. A lease can range
from one minute to 99 years. When the lease is up or released by the client
the DHCP server automatically retrieves it and reassigns it to other clients if
necessary. This is an efficient and accurate way to configure clients on the fly,
saving the administrator from an otherwise repetitive task. In doing so, IP
addresses can be shared among clients that do not require permanent IP
addresses.