AudioCodes Mediant 4000 SBC User Manual page 897

User's Manual
Parameter
SBC Survivability Registration Time
configure voip > sbc settings > sbc-surv-
rgstr-time
[SBCSurvivabilityRegistrationTime]
configure voip > sbc settings >
sas-notice
[SBCEnableSurvivabilityNotice]
SBC Dialog-Info Interworking
Version 7.2
60. Configuration Parameters Reference
Description
users may refresh their registration or subscription
simultaneously, thereby causing the device to handle
many such sessions at a given time. This may result
in an overload of the device (reaching maximum
session capacity), thereby preventing the
establishment of new calls or preventing the handling
of some user registration or subscription requests.
When this feature is enabled, the device assigns a
random expiry time to each user registration or
subscription and thus, ensuring future user
registration and subscription requests are more
distributed over time (i.e., do not all occur
simultaneously).
The device takes any random number between 0 and
the value configured by the parameter, and then
subtracts this random number from the original expiry
time value. For example, assume that the original
expiry time is 120 and the parameter is set to 10. If
the device randomly chooses the number 5 (i.e.,
between 0 and 10), the resultant expiry time will be
115 (120 minus 5).
The valid value is 0 to 20. The default is 10. If set to 0,
the device does not change the expiry time.
Note:

The lowest expiry time that the device sends in the
200 OK, regardless of the resultant calculation, is
10 seconds. For example, if the original expiry time
is 12 seconds and the parameter is set to 5,
theoretically, the new expiry time can be less than
10 (e.g., 12 – 4 = 8). However, the expiry time will
be set to 10.

The expiry time received from the user can be
changed by the device before forwarding it to the
proxy. This is configured by the
SBCUserRegistrationTime parameter.
Defines the duration of the periodic registrations
between the user and the device, when the device is
in survivability state (i.e., when REGISTER requests
cannot be forwarded to the proxy and are terminated
by the device). When set to 0, the device uses the
value set by the SBCUserRegistrationTime parameter
for the device's response.
The valid range is 0 to 2,000,000 seconds. The
default is 0.
Enables the device to notify Aastra IP phones that the
device is currently operating in Survivability mode.

[0] = Disable

[1] = Enable
For more information, see ''Enabling Survivability
Display on Aastra IP Phones'' on page 583.
Enables the interworking of dialog information
897 Mediant 4000 SBC