RFC 8757
Dynamic Link Exchange Protocol (DLEP) Latency Range Extension
RFC 8757: Dynamic Link Exchange Protocol (DLEP) Latency Range Extension 💖
okay bestie, the header is giving us the basics ✨ This is RFC 8757, published by the Internet Engineering Task Force (IETF) in March 2020. It's a Standards Track doc, so it's an official Internet standard, not just a vibe. It's written by B. Cheng (MIT Lincoln Laboratory) and L. Berger, Ed. (LabN Consulting, L.L.C.), and it's published under ISSN 2070-1721. It doesn't list anything it obsoletes or updates in the header, so it's its own little main character 💅
Abstract
this doc adds an extension to DLEP (Dynamic Link Exchange Protocol) that tells you the range of latency you can experience on a link 🦋
Status of This Memo
this is an Internet Standards Track document 🎀
it's a product of the IETF, so it represents the consensus of the IETF community. it got public review and was approved for publication by the Internet Engineering Steering Group (IESG). if you want more info on Internet Standards, check Section 2 of RFC 7841 🌸
for info on the current status of this doc, any errata, and how to give feedback, go to https://www.rfc-editor.org/info/rfc8757. 🧚
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. 💜
this doc is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) as they're in effect on the publication date. please actually read these, bestie, because they explain your rights and restrictions for this doc 🙈
one important bit: any Code Components pulled out of this doc must include Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions. they come without warranty, as described in the Simplified BSD License ⚠️
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. References
6.1. Normative References
6.2. Informative References
Acknowledgments
Authors' Addresses1. Introduction ✨
okay so DLEP is defined in [RFC8175] and it's the protocol where link-related control info gets swapped between DLEP peers 🔥 A DLEP peer is made of a modem and a router. DLEP has a base set of mechanisms plus room for extensions, and this doc is one of those extensions 💅
the base DLEP spec has the Latency Data Item, which gives you a single, implementation-dependent latency value on a link. this doc levels that up by letting you relay the minimum and maximum latency range seen on a link. the extension is called "Latency Range" 🌈
this doc defines a brand new DLEP Extension Type Value, which tells everyone the extension is in use (see Section 2). it also defines a new DLEP Data Item (see 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 doc 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 Latency Range Extension SHOULD be configurable 💖 To say the extension is being used, an implementation MUST include the Latency Range Extension Type Value in the Extensions Supported Data Item. the Extensions Supported Data Item gets sent and processed according to [RFC8175] 🫶
Note: using the extension defined here does not impact any processing tied to the Latency Data Item defined in [RFC8175]. no drama there 🙈
the Latency Range Extension Type Value is 4 (see Section 5) 🦋
3. Latency Range Data Item
the Latency Range Data Item does basically the same job as the Latency Data Item from [RFC8175], but it can also tell you the latency range that traffic can experience on a link 🌸 The Latency Range Data Item MUST be included in the Session Initialization Response Message, with default values used session-wide. it also MAY be carried in any message where the Latency Data Item [RFC8175] is allowed, as an additional data item 🧚 When it's present, the Latency Range Data Item MUST be processed under the same rules as the Latency Data Item defined in [RFC8175] 👑
here's the format, bestie 🍓
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+the fields, serve-able in order 💅
- Data Item Type:
28🎀 - 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. the longest possible wait, bestie 😭
- Minimum Latency: a 64-bit unsigned integer, representing the shortest transmission delay, in microseconds, that a packet can encounter as it is transmitted over the link. the shortest possible wait, and it's giving precision ✨
4. Security Considerations
okay this part is SERIOUS, so pay attention 🚨 The extension introduces a new Data Item for DLEP. It does not inherently introduce any additional vulnerabilities beyond the ones documented in [RFC8175]. The approach to security taken in that document applies equally when you run the extension defined in this document 🔐 no new security drama, but the old drama still applies, so keep it locked down 💀
5. IANA Considerations
here's the IANA situation 🌈 As described below, IANA has assigned two values per this document. Both assignments are to registries defined by [RFC8175] 🦋
5.1. Extension Type Value
IANA has assigned the following value in the "Extension Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy 🎀
+------+---------------+
| Code | Description |
+======+===============+
| 4 | Latency Range |
+------+---------------+
Table 1: New Extension
Type Value5.2. Data Item Value
IANA has assigned the following value in the "Data Item Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy 💜
+-----------+---------------+
| Type Code | Description |
+===========+===============+
| 28 | Latency Range |
+-----------+---------------+
Table 2: New Data Item Value6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B.
Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175,
DOI 10.17487/RFC8175, June 2017,
<https://www.rfc-editor.org/info/rfc8175>.6.2. Informative References
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.Acknowledgments
big thank-you to the members of the MANET working group for their helpful comments, especially Ronald in 't Velt, Henning Rogge, and Victoria Pritchard 🫶🌸
Authors' Addresses
Bow-Nan Cheng
MIT Lincoln Laboratory
Massachusetts Institute of Technology
244 Wood Street
Lexington, MA 02421-6426
United States of America
Email: bcheng@ll.mit.edu
Lou Berger (editor)
LabN Consulting, L.L.C.
Email: lberger@labn.netthat's the whole doc, bestie 👑 we love a well-specified protocol 🧚
📦 where this page comes from
- ietf: rfc8757 2020-03
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms