Dynamic Link Exchange Protocol (DLEP)
RFC 8175
Internet Engineering Task Force (IETF) S. Ratliff
Request for Comments: 8175 VT iDirect
Category: Standards Track S. Jury
ISSN: 2070-1721 Cisco Systems
D. Satterwhite
Broadcom
R. Taylor
Airbus Defence & Space
B. Berry
June 2017
Dynamic Link Exchange Protocol (DLEP)
Abstract
When routing devices rely on modems to effect communications over
wireless links, they need timely and accurate knowledge of the
characteristics of the link (speed, state, etc.) in order to make
routing decisions. In mobile or other environments where these
characteristics change frequently, manual configurations or the
inference of state through routing or transport protocols does not
allow the router to make the best decisions. This document
introduces a new protocol called the Dynamic Link Exchange Protocol
(DLEP), which provides a bidirectional, event-driven communication
channel between the router and the modem to facilitate communication
of changing link characteristics.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8175.
Ratliff, et al. Standards Track [Page 1]
RFC 8175 Dynamic Link Exchange Protocol (DLEP) June 2017
Copyright Notice
Copyright (c) 2017 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
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................4
2. Protocol Overview ...............................................7
2.1. Destinations ...............................................8
2.2. Conventions and Terminology ................................9
3. Requirements ....................................................9
4. Implementation Scenarios .......................................10
5. Assumptions ....................................................10
6. Metrics ........................................................11
7. DLEP Session Flow ..............................................12
7.1. Peer Discovery State ......................................12
7.2. Session Initialization State ..............................14
7.3. In-Session State ..........................................14
7.3.1. Heartbeats .........................................15
7.4. Session Termination State .................................15
7.5. Session Reset State .......................................16
7.5.1. Unexpected TCP Connection Termination ..............16
8. Transaction Model ..............................................16
9. Extensions .....................................................17
9.1. Experiments ...............................................18
10. Scalability ...................................................18
11. DLEP Signal and Message Structure .............................18
11.1. DLEP Signal Header .......................................19
11.2. DLEP Message Header ......................................20
11.3. DLEP Generic Data Item ...................................20
12. DLEP Signals and Messages .....................................21
12.1. General Processing Rules .................................21
12.2. Status Code Processing ...................................22
12.3. Peer Discovery Signal ....................................22
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