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pj_stun_msg_hdr Struct Reference
[STUN Message Representation and Parsing]

Data Fields

pj_uint16_t type
pj_uint16_t length
pj_uint32_t magic
pj_uint8_t tsx_id [12]

Detailed Description

This structure describes STUN message header. A STUN message has the following format:


        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |0 0|     STUN Message Type     |         Message Length        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         Magic Cookie                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                Transaction ID
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                                                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   

Field Documentation

The message length is the size, in bytes, of the message not including the 20 byte STUN header.

The magic cookie is a fixed value, 0x2112A442 (PJ_STUN_MAGIC constant). In the previous version of this specification [15] this field was part of the transaction ID.

The transaction ID is a 96 bit identifier. STUN transactions are identified by their unique 96-bit transaction ID. For request/ response transactions, the transaction ID is chosen by the STUN client and MUST be unique for each new STUN transaction generated by that STUN client. The transaction ID MUST be uniformly and randomly distributed between 0 and 2**96 - 1.

STUN message type, which the first two bits must be zeroes.


The documentation for this struct was generated from the following file:

 


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