0x295B SIP Subject Header

The subject header is also supported in the INFO message. The CSP allows the host for read and write access to the Subject header. The Subject Header TLV (0x295B) reports the Subject header within the PPL Event Indication for an inbound INFO message. This reporting of the Subject header in the INFO message is not configurable.

The Subject Header TLV (0x295B) is used in the PPL Event Request for outbound INFO to include the subject header. This TLV is also used in the PPL Event Request message for an outbound INFO message to include the subject header.

PPL Event Request message
PPL Event Indication message

Byte | Description
0, 1 | Tag 0x002B
2, 3 | Length Variable (Maximum of 250)
4-n | Value Null terminated ASCII string

Tag-Length-Value block. A standardized block that allows data to inserted in a standard way into API messages.
See Programmable Protocol Language.
A condition that, when met, drives a state machine from one state to another. A condition that drives a Component out of its current state by invoking an associated primitive.
American Standard Code for Information Interchange