AudioCodes Mediant 1000B User Manual page 343

User's Manual
Parameter
ySet]
SBC Client Forking Mode
enable-sbc-client-
forking
[IPGroup_EnableSBCClie
ntForking]
Version 7.0

[1] Enable = (Default) The device searches the Proxy Set table for a
Proxy Set that is configured with the same source IP address as that
of the incoming INVITE (if host name, then according to the
dynamically resolved IP address list). If such a Proxy Set is found,
the device classifies the INVITE as belonging to the IP Group
associated with the Proxy Set.
Note:

The parameter is applicable only to Server-type IP Groups.

For security, it is recommended to classify SIP dialogs based on
Proxy Set only if the IP address of the IP Group is unknown. In other
words, if the Proxy Set associated with the IP Group is configured
with an FQDN. In such cases, the device classifies incoming SIP
dialogs to the IP Group based on the DNS-resolved IP address. If
the IP address is known, it is recommended to use a Classification
rule instead (and disable the Classify by Proxy Set feature), where
the rule is configured with not only the IP address, but also with SIP
message characteristics to increase the strictness of the
classification process (see Configuring Classification Rules on page
635).
The reason for preferring classification based on Proxy Set when the
IP address is unknown is that IP address forgery (commonly known
as IP spoofing) is more difficult than malicious SIP message
tampering and therefore, using a Classification rule without an IP
address offers a weaker form of security. When classification is
based on Proxy Set, the Classification table for the specific IP Group
is ignored.

If you have assigned the same Proxy Set to multiple IP Groups,
disable the parameter and instead, use Classification rules to
classify incoming SIP dialogs to these IP Groups. If the parameter is
enabled, the device is unable to correctly classify incoming INVITEs
to their appropriate IP Groups.

Classification by Proxy Set occurs only if classification based on the
device's registration database fails (i.e., the INVITE is not from a
registered user).
Defines call forking of INVITE messages to up to five separate SIP
outgoing legs for User-type IP Groups. This occurs if multiple contacts
are registered under the same AOR in the device's registration
database.

[0] Sequential = (Default) Sequentially sends the INVITE to each
contact. If there is no answer from the first contact, it sends the
INVITE to the second contact, and so on until a contact answers. If
no contact answers, the call fails or is routed to an alternative
destination, if configured.

[1] Parallel = Sends the INVITE simultaneously to all contacts. The
call is established with the first contact that answers.

[2] Sequential Available Only = Sequentially sends the INVITE only
to available contacts (i.e., not busy). If there is no answer from the
first available contact, it sends the INVITE to the second contact, and
so on until a contact answers. If no contact answers, the call fails or
is routed to an alternative destination, if configured.
Note: The device can also fork INVITE messages received for a
Request-URI of a specific contact (user) registered in the database to
343
Description
Mediant 1000B Gateway and E- SBC
17. Control Network