AudioCodes Mediant 4000 SBC User Manual page 380

Parameter
Registrar Stickiness
registrar-stickiness
[Account_RegistrarStickiness]
Registrar Search Mode
registrar-search-mode
[Account_RegistrarSearchMode]
User's Manual
Description
header contains the source party number.
Enables the Registrar Stickiness feature, whereby the
device always routes SIP requests of a registered
Account to the same registrar server to where the last
successful REGISTER request was routed. In other
words, once initial registration of the Account to one of
the IP addresses in the Proxy Set (associated with the
Serving IP Group) is successful (i.e., 200 OK), binding
("stickiness") occurs to this specific address (registrar). All
future SIP requests (INVITEs, SUBSCRIBEs and
REGISTER refreshes) whose source and destination
match the Account are sent to this registrar only. This
applies until the registrar is unreachable or registration
refresh fails, for whatever reason.

[0] Disable = (Default) Disables the Registrar
Stickiness feature. After successful initial registration
of the Account with a registrar (IP address), whenever
the device receives a SIP request or registration
refresh, the device sends the request to whichever IP
address is the currently working registrar. In other
words, there is no binding to a specific IP address in
the Proxy Set and at any given time, requests may be
sent to a different IP address, whichever is the working
one. In the case of proxy load-balancing, there is no
certainty as to which IP address in the Proxy Set the
request is routed.

[1] Enable = Enables the Register Stickiness feature.
Note: The parameter is applicable only if you have
enabled Account registration ('Register' parameter
configured to Regular or GIN).
Defines the method for choosing an IP address (registrar)
in the Proxy Set (associated with the Serving IP Group) to
which the Account initially registers and performs
registration refreshes, when the Register Stickiness
feature is enabled. Once chosen, the Account is binded to
the IP address for subsequent SIP requests.

[0] Current Working Server = (Default) For each initial
and refresh registration request, the device routes to
the currently working server in the list of IP addresses
(configured or DNS-resolved IP addresses) in the
Proxy Set. In the case of proxy load-balancing, the
chosen IP address is according to the load-balancing
mechanism.

[1] According to IMS Specifications = For the initial
registration request, the device performs DNS
resolution if the address of the Proxy Set is configured
as an FQDN. It then attempts to register to one of the
listed DNS-resolved addresses (or configured IP
addresses), starting with the first listed address and
then going down the list sequentially. If an address
results in an unsuccessful registration, the device
immediately tries the next address (without waiting any
retry timeout). The device goes through the list of
addresses until an address results in a successful
380
Mediant 4000 SBC
Document #: LTRT-40203