User`s manual

MediaPack SIP User’s Manual 7. Using BootP / DHCP
Version 4.6 165 June 2005
7 Using BootP / DHCP
The MediaPack uses the Bootstrap Protocol (BootP) and the Dynamic Host Configuration
Protocol (DHCP) to obtain its networking parameters and configuration automatically after it is
reset. BootP and DHCP are also used to provide the IP address of a TFTP server on the network,
and files (cmp and ini) to be loaded into memory.
DHCP is a communication protocol that automatically assigns IP addresses from a central point.
BootP is a protocol that enables a device to discover its own IP address. Both protocols have
been extended to enable the configuration of additional parameters specific to the MediaPack.
A BootP/DHCP request is issued after a power reset (refer to the flow chart in Figure
10-3 on
page 205), or after a device exception.
Note: BootP is normally used to initially configure the MediaPack. Thereafter,
BootP is no longer required as all parameters can be stored in the gateway’s
non-volatile memory and used when BootP is inaccessible. BootP can be
used again to change the IP address of the MediaPack (for example).
7.1 BootP/DHCP Server Parameters
BootP/DHCP can be used to provision the following parameters (included in the BootP/DHCP
reply). Note that only the IP address and subnet mask are mandatory:
• IP address, subnet mask - These mandatory parameters are sent to the MediaPack every
time a BootP/DHCP process occurs.
• Default gateway IP address - An optional parameter that is sent to the MediaPack only if
configured in the BootP/DHCP server.
• TFTP server IP address - An optional parameter that contains the address of the TFTP
server from which the firmware (cmp) and ini files are loaded.
• DNS server IP address (primary and secondary) - Optional parameters that contain the IP
addresses of the primary and secondary DNS servers. These parameters are available only
in DHCP and from Boot version 1.92.
• Syslog server IP address - An optional parameter that is sent to the MediaPack only if
configured. This parameter is available only in DHCP.
• SIP server IP address – Two optional parameters that are sent to the MediaPack only if
configured. These parameters are available only in DHCP.
• Firmware file name – An optional parameter that contains the name of the firmware file to be
loaded to the gateway via TFTP.
• ini file name - An optional parameter that contains the name of the ini file to be loaded to the
gateway via TFTP.
7.2 Using DHCP
When the gateway is configured to use DHCP (DHCPEnable = 1), it attempts to contact the
enterprise’s DHCP server to obtain the networking parameters (IP address, subnet mask, default
gateway, primary/secondary DNS server and two SIP server addresses). These network
parameters have a ‘time limit’. After the time limit expires, the gateway must ‘renew’ its lease from
the DHCP server.
Note that if the DHCP server denies the use of the gateway's current IP address and specifies a
different IP address (according to RFC 1541), the gateway must change its networking
parameters. If this happens while calls are in progress, they are not automatically rerouted to the