Snom ONE IP Technical Manual page 70

Deploying the snom ONE IP Telephone System
50
•
Max. number of concurrent registrations per extension: This setting con-
trols how many user agents (i.e., phones) can be registered against an exten-
sion. This feature is useful if you want to restrict the number of phones that
can be registered to an extension. If this field is left blank, the extension will
have no limit.
•
Minimum Registration Time (s): In a SIP environment, the registrar deter-
mines how long a user agent may be registered. Short registration times have
a negative impact on the performance; however, it is critical that user agents
stabilize quickly once they've lost their connection to the system. This setting
defines the lower limit for the registration time. The default is 30 seconds.
•
Maximum Registration Time (s): This setting is used to define the upper
limit for the registration time. The default value is 360 seconds. See also Ap-
pendix B, "SIP Overview."
•
UDP NAT Refresh (s): If the registering user agent is behind NAT, the
system uses this setting to control the registration. The system registers agents
that use the UDP transport layer only for a short time so that the user agents
will re-register quickly and keep the NAT bindings alive. Typically, the settings
for UDP should be from 15 to 45 seconds since most NAT routers close ports
after 60 seconds of inactivity. The default for this setting is 30 seconds.
•
TCP/TLS NAT Refresh (s): This is similar to the UDP NAT refresh setting.
Since TCP/TLS connections do not need to refresh the bindings as often, a
value of a few minutes is okay in most situations. The default is set to 180
seconds (3 minutes).
•
Maximum call duration: This setting establishes an upper limit for the call
duration. By default, the setting is 2 hours (7200 seconds), but you can in-
crease this setting if you lean toward longer phone calls. This setting is crucial
for keeping your call list clean; for example, if one mailbox talks to another
mailbox or if a call does not drop properly, the system can automatically clean
this up.
•
Maximum ring duration (s): This setting determines the length of time the
system will wait before it disconnects a call.