Layer Two Tunneling Protocol - Version 3 (L2TPv3) - ICRQ

Incoming-Call-Request (ICRQ)

Incoming-Call-Request (ICRQ) is the control message sent by an LCCE to a peer when an incoming call is detected (although the ICRQ may also be sent as a result of a local event).  It is the first in a three-message exchange used for establishing a session via an L2TP control connection.

The ICRQ is used to indicate that a session is to be established between an LCCE and a peer.  The sender of an ICRQ provides the peer with parameter information for the session.  However, the sender makes no demands about how the session is terminated at the peer (i.e., whether the L2 traffic is processed locally, forwarded, etc.).

   The following AVPs MUST be present in the ICRQ:

•     Message Type
•     Local Session ID
•     Remote Session ID
•     Serial Number
•     Pseudowire Type
•     Remote End ID
•     Circuit Status