Routing Sbc; Configuring Classification Rules - AudioCodes Mediant 4000 SBC User Manual

CHAPTER 25 Routing SBC
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Routing SBC

This section describes configuration of call routing for the SBC application.

Configuring Classification Rules

The Classification table lets you configure up to 625 Classification rules. A Classification rule
classifies incoming SIP dialog-initiating requests (e.g., INVITE messages) to a "source" IP Group.
The source IP Group is the SIP entity that sent the SIP dialog request. Once classified, the device
uses the IP Group to process the call (manipulation and routing).
You can also use the Classification table for employing SIP-level access control for successfully
classified calls, by configuring Classification rules with whitelist and blacklist settings. If a
Classification rule is configured as a whitelist ("Allow"), the device accepts the SIP dialog and
processes the call. If the Classification rule is configured as a blacklist ("Deny"), the device rejects
the SIP dialog.
Configuration of Classification rules includes two areas:
■ Match: Defines the matching characteristics of the incoming IP call (e.g, source SIP Interface
and IP address). Classification is primarily based on the SIP Interface (as the matching
characteristics) on which the incoming dialog is received. As Classification rules must first be
assigned with an SRD, the SIP Interface is one that belongs to the SRD. Therefore,
Classification rules are configured per SRD, where multiple SIP Interfaces can be used as
matching characteristics. However, as multiple SRDs are relevant only for multi-tenant
deployments, for most deployments only a single SRD is required. As the device provides a
default SRD ("Default_SRD"), when only one SRD is required, the device automatically
assigns it to the Classification rule.
■ Action: Defines the action that is done if the incoming call matches the characteristics of the
rule (i.e., classifies the call to the specified IP Group).
The device searches the table from top to bottom for the first rule that matches the
characteristics of the incoming call. If it finds a matching rule, it classifies the call to the IP Group
configured for that rule. If you are using source tags to classify incoming calls to IP Groups, then
once the device locates a matching rule (including a match for the source tag), the device searches
the IP Groups table for an IP Group with the matching tag. For more information on classification
based on tags, see
Configure stricter classification rules higher up in the table than less strict rules to
ensure incoming dialogs are classified to the desired IP Group. Strict refers to the
number of matching characteristics configured for the rule. For example, a rule
configured with source host name and destination host name as matching
characteristics is stricter than a rule configured with only source host name. If the rule
configured with only source host name appears higher up in the table, the device
("erroneously") uses the rule to classify incoming dialogs matching this source host
name (even if they also match the rule appearing lower down in the table configured with
the destination host name as well).
If the device doesn't find a matching rule (i.e., classification fails), the device rejects or allows the
call depending on the following configuration:
➢
To configure the action for unclassified calls:
1. Open the SBC General Settings (Setup menu > Signaling & Media tab > SBC folder > SBC
General Settings).
Configuring Classification Based on Tags
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on page 544.