SIP Options Tag Handling
This section explains how to configure SIP options on a global or per-realm level and how to specify whether the feature treatment applies to traffic inbound to or outbound from a realm, or both.
SIP extensions that require specific behavior by UAs or proxies are identified by option tags. Option tags are unique identifiers used to designate new options (for example, extensions) in SIP. These option tags appear in the Require, Proxy-Require, and Supported headers of SIP messages.
Option tags are compatibility mechanisms for extensions and are used in header fields such as Require, Supported, Proxy-Require, and Unsupported in support of SIP.
The option tag itself is a string that is associated with a particular SIP option (i.e., an extension). It identifies this option to SIP endpoints.
Overview
The SIP specification (RFC 3261) requires that the Oracle® Enterprise Session Border Controller B2BUA reject any request that contains a Require header with an option tag the Oracle® Enterprise Session Border Controller does not support. However, many of these extensions operate transparently through the Oracle® Enterprise Session Border Controller's B2BUA. You can configure how SIP defines the Oracle® Enterprise Session Border Controllers B2BUA treatment of specific option tags.
Also, there might be certain extensions that an endpoint indicates support for by including the option tag in a Supported header. If you do not want a given extension used in your network, the you can configure SIP option tag handling to remove the undesired option tag from the Supported header. You can also specify how option tags in Proxy-Require headers are to be treated.
Configuration Overview
You configure the SIP feature element to define option tag names and their treatment by the Oracle® Enterprise Session Border Controller when the option tag appears in a Supported header, a Require header, and a Proxy-Require header. If an option tag is encountered that is not configured as a SIP feature, the default treatments apply. You only need to configure option tag handling in the SIP feature element when non-default treatment is required.
You can specify whether a SIP feature should be applied to a specific realm or globally across realms. You can also specify the treatment for an option based on whether it appears in an inbound or outbound packet. Inbound packets are those that are coming from a realm to the Oracle® Enterprise Session Border Controller and outbound packets are those which are going from the Oracle® Enterprise Session Border Controller to the realm.
The following tables lists the SIP option tag parameters you must configure.
Parameter | Description |
---|---|
name | SIP feature tag name |
realm | Realm name with which the feature will be associated. To make the feature global, leave the field empty. |
support mode inbound | Action for tag in Supported header in an inbound packet. |
require mode inbound | Action for tag in Require header in an inbound packet |
proxy require mode inbound | Action for tag in Proxy-Require header in an inbound packet |
support mode outbound | Action for tag in Supported header in an outbound packet |
require mode outbound | Action for tag in Require header in an outbound packet |
proxy require mode outbound | Action for tag in Proxy-Require header in an outbound packet |