Aastra 480i Administrator's Manual page 47

Aastra Web UI
Note: You can configure Advanced SIP
settings on a global-basis only.
1. Click on Advanced
Settings->Global SIP
->Advanced SIP Settings.
2. Enable the "Explicit MWI Sub-
scription" field by checking the
check box. (Disable this field by
unchecking the check box).
If the IP phone has a message
waiting subscription with the
Service Provider, a Message
Waiting Indicator (MWI) (LED
or display icon) tells the user
there is a message on the IP
Phone.
3. In the "Session Timer" field,
enter the time, in seconds, that
the IP phone uses to send peri-
odic re-INVITE requests to keep
a session alive. The proxy uses
these re-INVITE requests to
maintain the status' of the con-
nected sessions. See RFC4028
for details.
4. In the "Timer 1 and Timer 2"
fields, enter a time, in
milliseconds, that will apply to
an IP phone session. These tim-
ers are SIP transaction layer
timers defined in RFC 3261.
Timer 1 is an estimate of the
round-trip time (RTT). Default
is 500 msec.
Timer 2 represents the amount
of time a non-INVITE server
transaction takes to respond to a
request. Default is 4 seconds.
5. In the "Transaction Timer" field,
enter the amount of time, in mil-
liseconds, that the phone allows
the callserver (registrar/proxy)
to respond to SIP messages that
it sends. Valid values are 4000 to
64000. Default is 4000.
Note: If the phone does not receive a
response in the amount of time
designated for this parameter,
the phone assumes the message
has timed out.
6. In the "Transport Protocol"
field, select a transport protocol
to use when sending SIP Real-
time Transport Protocol (RTP)
packets. Valid values are User
Datagram Protocol (UDP),
Transmission Control Protocol
(TCP), or both.
7. Click
changes.
IP Phone SIP Admin Guide
to save your
39