Aastra Telecom 53I - Manual (Page 112)

Broadsoft Interoperability Features
106 RN-001029-00, Rev 03, Release 2.1
IP Phone Release Notes 2.1
Broadsoft Interoperability Features
“Hold” Feature Enhancement for Broadsoft Servers
In this release of the Aastra IP phones, the “Hold” feature has been enhanced as
described in RFC3264. The Hold feature allows IP phone users to put an active
call on “hold,” then retrieve the call later. This enhancement is intended for Aastra
IP phones operating with servers that support RFC3264 (for example, Broadsoft).
If a server does not support RFC3264, then the IP phones do not use RFC3264
functionality.
Centralized Conferencing for Broadsoft Servers
For information about this feature, see “Centralized Conferencing for Sylantro
Servers” on page 60 .
Support for the SIP “UPDATE” Message
This release of the Aastra IP phones supports the SIP UPDATE message, as
specified in RFC3311.
Support for SIP Server Blacklist
The server blacklist feature helps to reduce unnecessary delays during proxy/
registrar server failures, caused by the IP phone repeatedly sending SIP messages
to a failed server. If you enable this feature, then whenever the IP phone sends a
SIP message to a server, but does not get a response, the phone automatically adds
the server to the blacklist. The IP phone avoids sending messages to any servers
on the blacklist. If all servers are on the blacklist, then the IP phone attempts to
send the message to the first server on the list.
You can specify how long failed servers remain on the blacklist in the IP phone’s
configuration file. The default setting is 300 seconds. If you set the duration to 0
seconds, then you disable the blacklist feature.