Considerations For Ip Phones Supported By A Local Survivable Processor - Avaya G700 Installation Manual

Installing a New G700 with an S8300
Considerations for IP Phones Supported by a Local
Survivable Processor
A DHCP server assigns IP addresses to IP endpoints dynamically. Avaya IP phones perform a
DHCP discover request to receive an IP address, as well as receive parameters necessary to
function correctly. These parameters include the location of the call control server, the location
of the TFTP server, as well as the directory on the TFTP server from which the phone receives
its upgrades.
When preparing a DHCP server to work with Avaya IP phones, there is an option that must be
administered to allow the Avaya phone to receive the DHCP offer. This option is
"site-specific-option-number" (sson) 176. Different DHCP servers allow for this administration in
different ways, but the sson option must be mapped to 176. Then the option can be set up to
send the information desired to the Avaya phones for the intended activity.
The sson option sends a string that includes the IP address of the Avaya Call Controller with
which the phone will register ("MCIPADD=www.xxx.yyy.zzz"). In an S8500 or S8700 system,
this is a CLAN address; in an S8300 system, this is the IP address of the S8300. Multiple
addresses can be administered to allow for LSP failover. The second address in the MCIPADD
list may be an IP address for a second S8700 CLAN board or an LSP. If a second CLAN board
is used, then the third address must be the LSP, and any subsequent addresses should be
alternate LSPs. Local LSPs should appear first in the list, with remote LSPs later in the list as
possible back ups.
If an IP phone looses its connection to the primary controller, it will try to register with an LSP
associated with its network region (as defined on page 3 of the IP Network Region form).
However, if the phone resets, it looses this information and goes to the DHCP server for a
controller. If the only controller in the MCIPADD list is the primary controller, and if the
connection to the primary controller is down, the phone cannot register. Having an LSP in the
MCIPADD list gives the IP phones an alternate controller in this situation.
Note:
It is strongly recommended that at least one LSP be administered in the
Note:
MCIPADD list.
Also included in the sson option string is the "MCPORT=1719". This is the port the phone will
listen on for signalling traffic to the call controller. Next is the tftp server field. This field indicates
to the phone where it is to receive firmware updates, along with the tftp directory field.
186 Installation and Upgrades for Avaya G700 Media Gateway and Avaya S8300 Media Server