GTP Tunnel Request for Mobile IPv6
draft-perkins-mext-gtpdata-01.txt

Abstract

Widely deployed mobility management systems for wireless communications use GTP for transmitting packets to mobility agents serving the mobile node. In order to enable use of Proxy Mobile IPv6 in such telecommunication systems, GTP should be allowed as a tunneling choice for packets between the LMA and the MAG. This specification allocates a new bit (the 'G' bit) in the Proxy Binding Update for the purpose of enabling GTP tunneling.

Status of this Memo

This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/.

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This Internet-Draft will expire on February 02, 2012.

Copyright Notice

Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document.

1. Introduction

Widely deployed mobility management systems for wireless communications use GTP [TS_29-060] for transmitting packets to mobility agents serving the mobile node. In order to enable use of Proxy Mobile IPv6 in such telecommunication systems, GTP [RFC5213] should be allowed as a tunneling choice for packets between the LMA and the MAG. This specification allocates a new bit (the 'G' bit) in the Proxy Binding Update for the purpose of enabling GTP tunneling. This specification does not introduce any modifications to GTP. Considerations about the use of GTP-C for establishing binding updates is outside the scope of this specification.

2. GTP tunneling bit in Binding Update

In order to request GTP tunneling, the 'G' bit is set in the Binding Update. This is also useful when the 'P' bit is set, so that the MAG can indicate that the LMA should use GTP as the tunneling protocol for proxy packet delivery.

	                            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	                            |          Sequence #           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |A|H|L|K|M|R|P|G|    Reserved   |           Lifetime            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                                                               |
    .                                                               .
    .                        Mobility options                       .
    .                                                               .
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

G

The 'G' bit is allocated from the previously reserved bits in the Binding Update header.

3. New Status Code for GTP tunneling rejection

The Status is an 8-bit unsigned integer field in a Binding Acknowledgement message, indicating the disposition of the Binding Update. Values of the Status field less than 128 indicate that the Binding Update was accepted by the receiving node. Values greater than or equal to 128 indicate that the Binding Update was rejected by the receiving node. The following new Status value is specified for use when the receiving node cannot provide GTP as a tunneling option.

TBD

Invalid Tunnel Format

4. Security Considerations

This document does not introduce any security mechanisms, and does not have any impact on existing security mechanisms. Tunneling of data via GTP does not introduce any known security vulnerabilities.

5. IANA Considerations

This document allocates a new bit from the reserved field of the Binding Update message header. The new bit is denoted the 'G' bit. This document also creates a new "Status Code" for the Status field in the Binding Acknowledgement message. The new status code, "Invalid Tunnel Format", indicates rejection of the requested tunneling mode in the Binding Update, and is needed if the receiver of the Binding Update does not offer GTP encapsulation. The new Status Code is required to be allocated from the values larger than 128 in order to indicate that the Binding Update was rejected.

6. References

Author's Address

Table of Contents

• 1. Introduction
• 2. GTP tunneling bit in Binding Update
• 3. New Status Code for GTP tunneling rejection
• 4. Security Considerations
• 5. IANA Considerations
• 6. References
• Author's Address