Avaya 1600 Series Administrator's Manual page 48

The 1600 Series IP Deskphones do not support Regular Expression Matching, and therefore, do not
use wildcards. For more information, see
page 65.
In configurations where the upgrade script and application files are in the default directory on the HTTP
server, do not use the HTTPDIR=<path>.
You do not have to use Option 242. If you do not use this option, you must ensure that the key
information, especially HTTPSRVR and MCIPADD, is administered appropriately elsewhere.
Avaya recommends that you administer DHCP servers to deliver only the options specified in this
document. Administering additional, unexpected options might have unexpected results, including
causing the IP deskphone to ignore the DHCP server.
The media server name and HTTP server name must each be no more than 32 characters in length.
Examples of good DNS administration include:
- Option 6: "aaa.aaa.aaa.aaa"
- Option 15: "dnsexample.yourco.com,zzz.zzz.zzz.zzz"
- Option 242: "MCIPADD=xxxx.xxx.xxx.xxx"
Depending on the DHCP application you choose, be aware that the application most likely
does not immediately recycle expired DHCP leases. An expired lease might remain reserved
for the original client a day or more. For example, Windows NT
leases for about one day. This reservation period protects a lease for a short time. If the client
and the DHCP server are in two different time zones, the clocks of the computers are not in
sync, or the client is not on the network when the lease expires, there is time to correct the
situation.
The following example shows the implication of having a reservation period: Assume two IP
addresses, therefore two possible DHCP leases. Assume three IP deskphones, two of which
are using the two available IP addresses. When the lease for the first two deskphones
expires, the third deskphone cannot get a lease until the reservation period expires. Even if
the other two deskphones are removed from the network, the third deskphone remains
without a lease until the reservation period expires.
Administering Options for the 1600 Series IP Deskphones
DHCP Server Administration
®
DHCP reserves expired
Issue 6 August 2014
on
41