AudioCodes Mediant 500L User Manual page 1225

User's Manual
Parameter
configure voip > sbc settings > sbc-
max-fwd-limit
[SBCMaxForwardsLimit]
SBC Session-Expires
configure voip > sbc settings > sbc-
sess-exp-time
[SBCSessionExpires]
Minimum Session-Expires
configure voip > sbc settings > min-
session-expires
[SBCMinSE]
configure voip > sbc settings > sbc-
session-refresh-policy
[SBCSessionRefreshingPolicy]
Version 7.2
Defines the Max-Forwards SIP header value. The Max-
Forwards header is used to limit the number of servers (such
as proxies) that can forward the SIP request. The Max-
Forwards value indicates the remaining number of times this
request message is allowed to be forwarded. This count is
decremented by each server that forwards the request.
The parameter affects the Max-Forwards header in the
received message as follows:

If the received header's original value is 0, the message is
not passed on and is rejected.

If the received header's original value is less than the
parameter's value, the header's value is decremented
before being sent on.

If the received header's original value is greater than the
parameter's value, the header's value is replaced by the
user-defined parameter's value.
The valid value range is 1-70. The default is 10.
Defines the SBC session refresh timer (in seconds) in the
Session-Expires header of outgoing INVITE messages.
The valid value range is 90 (according to RFC 4028) to 86400.
The default is 180.
Defines the minimum amount of time (in seconds) between
session refresh requests in a dialog before the session is
considered timed out. This value is conveyed in the SIP Min-
SE header.
The valid range is 0 (default) to 1,000,000, where 0 means that
the device does not limit Session-Expires.
Defines the SIP user agent responsible for periodically sending
refresh requests for established sessions (active calls). The
session refresh allows SIP UAs or proxies to determine the
status of the SIP session. When a session expires, the session
is considered terminated by the UAs, regardless of whether a
SIP BYE was sent by one of the UAs.
The SIP Session-Expires header conveys the lifetime of the
session, which is sent in re-INVITE or UPDATE requests
(session refresh requests). The 'refresher=' parameter in the
Session-Expires header (sent in the initial INVITE or
subsequent 2xx response) indicates who sends the session
refresh requests. If the parameter contains the value 'uac', the
device performs the refreshes; if the parameter contains the
value 'uas', the remote proxy performs the refreshes. An
example of the Session-Expires header is shown below:
Session-Expires: 4000;refresher=uac
Thus, the parameter is useful when a UA does not support
session refresh requests or does not support the indication of
who performs session refresh requests. In such a scenario, the
device can be configured to perform the session refresh
requests.

[0] Remote Refresher = (Default) The UA (proxy) performs
the session refresh requests. The device indicates this to
1225
69. Configuration Parameters Reference
Description
Mediant 500L Gateway & E-SBC