DLEP Latency Range Extension
draft-ietf-manet-dlep-latency-extension-02

Abstract

This document defines an extension to the DLEP protocol to provide the range of latency that may be experienced on a link.

Status of This Memo

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

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This Internet-Draft will expire on August 18, 2018.

Copyright Notice

Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 1.1. Key Words
• 2. Extension Usage and Identification
• 3. Latency Range Data Item
• 4. Security Considerations
• 5. IANA Considerations
• 5.1. Extension Type Value
• 5.2. Data Item Value
• 6. Normative References
• Appendix A. Acknowledgments
• Authors' Addresses

1. Introduction

The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175]. It provides the exchange of link related control information between DLEP peers. DLEP peers are comprised of a modem and a router. DLEP defines a base set of mechanisms as well as support for possible extensions. This document defines one such extension.

The base DLEP specification includes the Latency metric which provides a single latency value on a link, which is implementation dependent. This document adds the ability to relay the minimum and maximum latency range seen on a link. The extension defined in this document is referred to as "Latency Range".

This document defines a new DLEP Extension Type Value in Section 2 which is used to indicate the use of the extension, and one new DLEP Data Item in Section 3.

1.1. Key Words

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. Extension Usage and Identification

The use of the Latency Range Extension SHOULD be configurable. To indicate that the Latency Range Extension is to be used, an implementation MUST include the Latency Range Extension Type Value in the Extensions Supported Data Item. The Extensions Supported Data Item is sent and processed according to [RFC8175].

The Latency Range Extension Type Value is TBA1, see Section 5.

3. Latency Range Data Item

The Latency Range Data Item serves much the same purpose as the Latency Data Item defined in [RFC8175] with the addition of being able to communicate the latency range that may be experienced by traffic on a link. The Latency Range Data Item MAY be carried in the same messages and MUST be processed according to the same rules as the Latency Data Item defined in [RFC8175].

The format of the Latency Range Data Item is:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Data Item Type                | Length                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Maximum Latency                        :
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   :                        Maximum Latency                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Minimum Latency                        :
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   :                        Minimum Latency                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Data Item Type:

TBA2

Length:

16

Maximum Latency:

A 64-bit unsigned integer, representing the longest transmission delay, in microseconds, that a packet encounters as it is transmitted over the link.

Minimum Latency:

A 64-bit unsigned integer, representing the shortest transmission delay, in microseconds, that a packet encounters as it is transmitted over the link.

4. Security Considerations

The extension introduces a new Data Item for the DLEP protocol. The extension does not inherently introduce any additional threats above those documented in [RFC8175]. The approach taken to Security in that document applies equally when running the extension defined in this document.

5. IANA Considerations

This document requests the assignment of 2 values by IANA. All assignments are to registries defined by [RFC8175].

5.1. Extension Type Value

This document requests one new assignment to the DLEP Extensions Registry named "Extension Type Values" in the range with the "Specification Required" policy. The requested value is as follows:

5.2. Data Item Value

This document requests one new assignment to the DLEP Data Item Registry named "Data Item Type Values" in the range with the "Specification Required" policy. The requested values are as follows:

6. Normative References

Appendix A. Acknowledgments

Helpful comments were received from members of the MANET working grouping, including Ronald in 't Velt, Henning Rogge, and Victoria Pritchard.

Authors' Addresses