Avaya 3641 Installation, Configuration And Administration page 41

Avaya 3641/3645 Wireless IP Telephone Overview
Ensure that all your APs are attached to the same subnet for proper operation. The
handset can change subnets if DHCP is enabled and the handset is powered off then back
on when within range of APs on the new subnet. Note that the wireless telephones cannot
"roam" across subnets, since they cannot change IP addresses while operational.
TFTP (Trivial File Transfer Protocol) Server
A TFTP server is required in the system to distribute software to the Wireless IP
Telephones and AVPP Server. It may be on a different subnet than the supported Avaya IP
telephony device(s) and APs.
NTP (Network Time Protocol) Server
An NTP server is optional except when using WPA2 Enterprise.
If WPA2 Enterprise security with PEAP authentication is used, the handset will validate
the PEAP certificate has a valid date and time. If the ACM call server specifies the
current time to be used by the handset, that time will be used for PEAP certificate
validation. If an NTP server is also present in the system, the handset will use the NTP
time for validation until handset time is overwritten by the ACM. If an NTP Server is not
available, the certificate will be deemed valid and operate accordingly.
Authentication Server (if using WPA2 Enterprise)
A RADIUS authentication server must be used to provide username/password based
authentication using RSA certificates for PEAPv0/MSCHAPv2 or PAC files for EAP-FAST.
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