User`s manual

H.323 User's Manual 11. Advanced System Capabilities
Version 5.0 301 December 2006
11.4 Startup Process
The startup process (illustrated in Figure 11-3 on page 302) begins when the gateway is
reset (physically or from the Web / SNMP) and ends when the operational software is
running. In the startup process, the network parameters, software and configuration files
are obtained.
After the gateway powers up or after it is physically reset, it broadcasts a BootRequest
message to the network. If it receives a reply (from a BootP server), it changes its network
parameters (IP address, subnet mask and default gateway address) to the values
provided. If there is no reply from a BootP server and if DHCP is enabled (DHCPEnable =
1), the gateway initiates a standard DHCP procedure to configure its network parameters.
After changing the network parameters, the gateway attempts to load the cmp and various
configuration files from the TFTP server’s IP address, received from the BootP/DHCP
servers. If a TFTP server’s IP address isn’t received, the gateway attempts to load the
software (cmp) file and / or configuration files from a preconfigured TFTP server (refer to
Section 11.3 on page 298). Thus, the gateway can obtain its network parameters from
BootP or DHCP servers and its software and configuration files from a different TFTP
server (preconfigured in ini file).
If BootP/DHCP servers are not found or when the gateway is reset from the Web / SNMP,
it retains its network parameters and attempts to load the software (cmp) file and / or
configuration files from a preconfigured TFTP server.
If a preconfigured TFTP server doesn’t exist, the gateway operates using the existing
software and configuration files loaded on its non-volatile memory.
Notes:
• After the operational software runs, if DHCP is configured, the
gateway attempts to renew its lease with the DHCP server.
• Though DHCP and BootP servers are very similar in operation, the
DHCP server includes some differences that could prevent its
operation with BootP clients. However, many DHCP servers, such as
Windows
™
NT DHCP server, are backward-compatible with BootP
protocol and can be used for gateway configuration.
• The time duration between BootP/DHCP requests is set to 1 second
by default. This can be changed by the BootPDelay ini file parameter.
Also, the number of requests is 3 by default and can be changed by
BootPRetries ini file parameter (both parameters can also be set using
the BootP command line switches).