Bootp Preferences; Tftp Preferences - 3Com VCX V7122 User Manual

BootP Preferences

ARP is a common acronym for Address Resolution Protocol, and is the method used by all
Internet devices to determine the link layer address, such as the Ethernet MAC address, in
order to route Datagrams to devices that are on the same subnet.
When ARP Manipulation is enabled on this screen, the BootP Tool creates an ARP cache
entry on your computer when it receives a BootP BootRequest from the VoIP gateway. Your
computer uses this information to send messages to the VoIP gateway without using ARP
again. This is particularly useful when the gateway does not yet have an IP address and,
therefore, cannot respond to an ARP.
Because this feature creates an entry in the computer ARP cache, Administrator Privileges
are required. If the computer is not set to allow administrator privileges, ARP Manipulation
cannot be enabled.
ARP Manipulation Enabled: Enable ARP Manipulation to remotely reset a gateway that
does not yet have a valid IP address.
If ARP Manipulation is enabled, the following two commands are available.
Reply Type: Reply to a BootRequest can be either Broadcast or Unicast. The default
for the BootP Tool is Broadcast. In order for the reply to be set to Unicast, ARP
Manipulation must first be enabled. This then enables the BootP Tool to find the MAC
address for the client in the ARP cache so that it can send a message directly to the
requesting device. Normally, this setting can be left at Broadcast.
ARP Type: The type of entry made into the ARP cache on the computer, once ARP
Manipulation is enabled, can be either Dynamic or Static. Dynamic entries expire after
a period of time, keeping the cache clean so that stale entries do not consume computer
resources. The Dynamic setting is the default setting and the setting most often used.
Static entries do not expire.
Number of Timed Replies: This feature is useful for communicating to VoIP gateways
that are located behind a firewall that would block their BootRequest messages from
getting through to the computer that is running the BootP Tool. You can set this value to
any whole digit. Once set, the BootP Tool can send that number of BootReply messages
to the destination immediately after you send a remote reset to a VoIP gateway at a valid
IP address. This enables the replies to get through to the VoIP gateway even if the
BootRequest is blocked by the firewall. To turn off this feature, set the Number of Timed
Replies = 0.

TFTP Preferences

Enabled: To enable the TFTP functionality of the BootP Tool, check the box beside this
heading. If you want to use another TFTP application, other than the one included with
the BootP Tool, unselect the box.
On Interface: This pull down menu displays all network interfaces currently available on
the computer. Select the interface that you want to use for the TFTP. Normally, there is
only one choice.
Directory: This option is enabled only when the TFTP is enabled. Use this parameter to
specify the folder that contains the files for the TFTP utility to manage (cmp, ini, Call
Progress Tones, etc.).
198 3Com VCX V7122 SIP VoIP Gateway User Manual