Configuring Sip Message Policy Rules - AudioCodes Mediant 3000 User Manual

User's Manual
Parameter
19.5

Configuring SIP Message Policy Rules

The Message Policy table lets you configure up to 5 SIP Message Policy rules. SIP
Message Policy rules are used to block (blacklist) unwanted incoming SIP messages or
permit (whitelist) receipt of desired SIP messages. You can configure legal and illegal
characteristics of a SIP message. This feature is helpful against VoIP fuzzing (also known
as robustness testing), which sends different types of packets to its "victims" for finding
bugs and vulnerabilities. For example, the attacker might try sending a SIP message
containing either an oversized parameter or too many occurrences of a parameter.
To apply SIP Message Policy rules, you need to assign them to SIP Interfaces associated
with the relevant IP Groups (see ''Configuring SIP Interfaces'' on page 337).
Each Message Policy rule can be configured with the following:

Maximum message length

Maximum header length

Maximum message body length

Maximum number of headers

Maximum number of bodies

Option to send 400 "Bad Request" response if message request is rejected

Blacklist and whitelist for defined methods (e.g., INVITE)

Blacklist and whitelist for defined bodies
The following procedure describes how to configure Message Policy rules through the Web
interface. You can also configure it through ini file (MessagePolicy).

To configure SIP Message Policy rules:
1. Open the Message Policy table (Configuration tab > VoIP menu > SIP Definitions >
Msg Policy & Manipulation > Message Policy Table).
Version 7.0
example is shown in the beginning of this section. The option allows
you to use the same condition for multiple manipulation rules.
Notes:

When configured to Use Previous Condition, the 'Message Type' and
'Condition' parameters are not applicable and if configured are
ignored.

When multiple manipulation rules apply to the same header, the next
rule applies to the resultant string of the previous rule.
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Description
19. SIP Definitions
Mediant 3000