AudioCodes Mediant 4000 SBC User Manual page 569

CHAPTER 25 Routing SBC
2. From the 'Unclassified Calls' drop-down list, select Reject to reject unclassified calls or Allow
to accept unclassified calls:
3. Click Apply.
If you configure the parameter to Allow, the incoming SIP dialog is assigned to an IP Group as
follows:
1. The device determines on which SIP listening port (e.g., 5061) the incoming SIP dialog request
was received and the SIP Interface configured with this port (in the SIP Interfaces table).
2. The device determines the SRD associated with this SIP Interface (in the SIP Interfaces table)
and then classifies the SIP dialog to the first IP Group in the IP Groups table that is associated
with the SRD. For example, if IP Groups 3 and 4 belong to the same SRD, the device
classifies the call to IP Group 3.
The Classification table is used to classify incoming SIP dialog requests only if the following
classification stages fail:
1. Classification Stage 1 - Based on User Registration Database: The device searches its
users registration database to check whether the incoming SIP dialog arrived from a registered
user. The device searches the database for a user that matches the address-of-record (AOR)
and Contact of the incoming SIP message:
● Compares the SIP Contact header to the contact value in the database.
● Compares the URL in the SIP P-Asserted-Identity/From header to the registered AOR in
the database.
If the device finds a matching registered user, it classifies the user to the IP Group associated
with the user in the database. If this classification stage fails, the device proceeds to
classification based on Proxy Set.
2. Classification Stage 2 - Based on Proxy Set: If the database search fails, the device
performs classification based on Proxy Set. This classification is applicable only to Server-
type IP Groups and is done only if classification based on Proxy Set is enabled (see the
'Classify By Proxy Set' parameter in the IP Groups table in
checks whether the incoming INVITE's IP address (if host name, then according to the
dynamically resolved IP address list) is configured for a Proxy Set (in the Proxy Sets table). If
such a Proxy Set exists, the device classifies the INVITE to the IP Group that is associated
with the Proxy Set. The Proxy Set is assigned to the IP Group in the IP Groups table.
If more than one Proxy Set is configured with the same IP address and associated with the
same SIP Interface, the device may classify and route the SIP dialog to an incorrect IP Group.
In such a scenario, a warning is generated in the Syslog message. However, if some Proxy
Sets are configured with the same IP address but different ports (e.g., 10.1.1.1:5060 and
10.1.1.1:5070) and the 'Classification Input' parameter is configured to IP Address, Port &
Transport Type, classification (based on IP address and port combination) to the correct IP
Group is achieved. Therefore, when classification is by Proxy Set, pay attention to the
configured IP addresses and the 'Classification Input' parameter of your Proxy Sets. When
more than one Proxy Set is configured with the same IP address, the device selects the
matching Proxy Set in the following precedence order:
a. Selects the Proxy Set whose IP address, port, and transport type match the source of the
incoming dialog.
b. If no match is found for a), it selects the Proxy Set whose IP address and transport type
match the source of the incoming dialog (if the 'Classification Input' parameter is
configured to IP Address Only).
c. If no match is found for b), it selects the Proxy Set whose IP address match the source of
the incoming dialog (if the 'Classification Input' parameter is configured to IP Address
Only).
Configuring IP
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Mediant 4000 SBC | User's Manual
Groups). The device