RFC 3145 (rfc3145) - Page 2 of 10
L2TP Disconnect Cause Information
Alternative Format: Original Text Document
RFC 3145 L2TP Disconnect Cause Information July 2001 disconnect information to its peer. This AVP should be used in conjunction with, and not as a replacement for, the L2TP Result and Error Code AVPs. The PPP Disconnect Cause Code AVP can also be used to provide a human-readable disconnect reason to the user. This AVP should not have any effect on either the functioning of the tunnel or the functioning of the PPP session; it is for informational and logging purposes only. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [2]. 2. PPP Disconnect Cause Code AVP The AVP is valid in the L2TP Call-Disconnect-Notify (CDN) message only, and it MUST NOT be marked Mandatory. The PPP Disconnect Cause Code AVP is encoded with Vendor ID 0 and an Attribute Type of PPP Disconnect Cause Code (46). The length of the Value field MUST be at least 11 octets. If the length is more than 11 octets, the additional octets MUST contain a descriptive text in UTF-8 [3] format that can be displayed to the user or in a log file. The format of the AVP is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |M|H| rsvd | Length | Vendor ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attribute Type | Disconnect Code | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Control Protocol Number | Direction | Message... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Figure 1: PPP Disconnect Cause Code AVP Mandatory (M) bit: MUST be 0. Hidden (H) bit: MAY be 1 if the attribute is hidden. Length: The length of the entire attribute in octets, expressed as a single octet. The length MUST be at least 11. Vendor ID: A two octet value in network byte order; set to 0 to indicate that this is an IETF-assigned attribute. Verma, et al. Standards Track



