Mobile IP Vendor/Organization-Specific Extensions
obsoleted by
- rfc-3115 — Mobile IP Vendor/Organization-Specific Extensions
Extracted elements (20)
The CVSE uses a 2-octet Length field while the NVSE uses a 1-octet Length field. This distinction supports the CVSE's critical nature requiring more potential data, while keeping the NVSE format compact for non-critical optional extensions.
The Vendor/Org-ID uses the SMI Network Management Private Enterprise Code (high-order octet=0, low-order 3 octets = enterprise code in network byte order) to uniquely identify vendors/organizations without requiring a new registry, leveraging the existing IANA enterprise number assignment.
Per RFC 2002, extensions numbered 0-127 that are unrecognized in a registration message must be silently discarded. CVSE-TYPE-NUMBER (37) falls in this range, so the RFC clarifies that the CVSE-specific error handling applies when the type is recognized but the vendor ID or vendor type is not supported.
If a transit node for a registration reply receives a recognized CVSE with an unknown/unsupported vendor ID or Vendor-CVSE-Type, a registration reject MUST be sent with the appropriate error code. For example, an FA receiving an unknown CVSE in a reply from the HA must send a registration reject to the MN.
Implementations that silently discard datagrams SHOULD provide the capability of logging the error including the discarded datagram contents, and SHOULD record the event in a statistics counter.
Multiple TLVs with types CVSE-TYPE-NUMBER and NVSE-TYPE-NUMBER can be included in a message and can be placed anywhere after the fixed portion of the Mobile IP message; they are expected to be protected by the corresponding authenticator as necessary.
Ordering of CVSE and NVSE TLVs MUST NOT be modified by intermediate nodes.
The Reserved field in the CVSE MUST be set to 0 on sending and MUST be ignored on reception.
When a CVSE is encountered but not recognized, the message containing the extension MUST be silently discarded.
When a Mobile IP entity receives a message with a recognized NVSE but unknown/unsupported vendor ID or Vendor-NVSE-Type, the entire extension is skipped (not the message).
When a Mobile IP entity receives a registration request with a recognized CVSE but an unknown/unsupported vendor ID or Vendor-CVSE-Type, a registration reject MUST be sent with an error code indicating rejection due to unknown CVSE.
When a NVSE is encountered but not recognized, the extension SHOULD be ignored, but the rest of the extensions and message data MUST still be processed.
Four new error codes are defined: ERROR-FA-1 (100) and ERROR-FA-2 (101) for Foreign Agent rejection due to unsupported Vendor-ID or Vendor-CVSE-Type in CVSE from MN or HA respectively; ERROR-HA-1 (140) and ERROR-HA-2 (141) for Home Agent rejection due to unsupported Vendor-ID or Vendor-CVSE-Type in CVSE from MN or FA respectively.
The Critical Vendor/Organization Specific Extension (CVSE) is a Mobile IP extension with Type=37, a 1-octet Reserved field, a 2-octet Length field, a 4-octet Vendor/Org-ID (high-order octet 0, low-order 3 octets are SMI Network Management Private Enterprise Code), a 2-octet Vendor-CVSE-Type, and variable-length Vendor-CVSE-Value.
The Normal Vendor/Organization Specific Extension (NVSE) is a Mobile IP extension with Type=133, a 1-octet Length field, a 2-octet Reserved field, a 4-octet Vendor/Org-ID, a 2-octet Vendor-NVSE-Type, and variable-length Vendor-NVSE-Value.
IANA assigned new Foreign Agent error codes ERROR-FA-1 (100) and ERROR-FA-2 (101) and new Home Agent error codes ERROR-HA-1 (140) and ERROR-HA-2 (141), all taken from the Mobile IP error code numbering spaces.
IANA assigned Type value 37 (CVSE-TYPE-NUMBER) for the Critical Vendor/Organization Specific Extension and Type value 133 (NVSE-TYPE-NUMBER) for the Normal Vendor/Organization Specific Extension, both from the Mobile IP registration extensions numbering space.
This document assumes Mobile IP messages are authenticated using methods defined by the Mobile IP protocol and imposes no additional security requirements. The vendor-specific extensions are expected to be protected by the corresponding Mobile IP authenticators.
CVSE wire format: Type (1 octet, value 37), Reserved (1 octet), Length (2 octets), Vendor/Org-ID (4 octets, high-order octet=0 + 3-octet SMI enterprise code in network byte order), Vendor-CVSE-Type (2 octets), Vendor-CVSE-Value (variable).
NVSE wire format: Type (1 octet, value 133), Length (1 octet), Reserved (2 octets), Vendor/Org-ID (4 octets, high-order octet=0 + 3-octet SMI enterprise code in network byte order), Vendor-NVSE-Type (2 octets), Vendor-NVSE-Value (variable).