A DODAG Metric Used for DODAG Selection in Low-Power and Lossy Networks
draft-hushe-roll-dodag-metric-00
ROLL H. She
Internet-Draft L. Zhao
Intended status: Standards Track P. Thubert
Expires: 21 June 2021 Cisco Systems
18 December 2020
A DODAG Metric Used for DODAG Selection in Low-Power and Lossy Networks
draft-hushe-roll-dodag-metric-00
Abstract
This document extends [RFC6551] by defining a new DODAG metric called
DODAG size, which can be used for DODAG selection in Low-Power and
Lossy Networks (LLNs). DODAG size is an important metric for nodes
to decide which DODAG to join, or which DODAG to migrate. This
document proposes methods to disseminate DODAG size from the Root to
all nodes in the DODAG, so that the DODAG size can be advertised to
new joining nodes.
Status of This Memo
This Internet-Draft is submitted 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 https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 21 June 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
She, et al. Expires 21 June 2021 [Page 1]
Internet-Draft DODAG size December 2020
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://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. Code Components
extracted from this document must 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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. References . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3. Requirements Language . . . . . . . . . . . . . . . . . . 4
3. Disseminating DODAG size . . . . . . . . . . . . . . . . . . 4
3.1. DODAG Size Object . . . . . . . . . . . . . . . . . . . . 4
3.2. Disserminating DODAG size through DIO . . . . . . . . . . 5
3.3. Disserminating DODAG size through DAO-ACK . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
7. Normative References . . . . . . . . . . . . . . . . . . . . 6
8. Informative References . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Low-power and Lossy Networks (LLNs) typically consist of large number
of nodes connected by lossy and unstable links. Such networks are
typically compised of nodes that are constrained in CPU power,
memory, and energy.
RPL, the "Routing Protocol for LLNs" [RFC6550], is an IPv6 routing
procotol with specific optimizations for such networks. RPL builds
routes proactively but maintains them on-demand based on their
utilization. Point-to-multipoint (P2MP) and multipoint-to-point
(MP2P) routes to and from the Root are optimized, but other point-to-
point (P2P) routes are stretched to minimize the control traffic and
the state in every node.
When used in conjunction with IEEE Std. 802.15.4 [IEEE802154], RPL
can be used to form a Personal Area Network (PAN) composed by a
6LoWPAN Border Router (6LBR) that is typically collocated with the
DODAG Root, and multiple 6LoWPAN Nodes (6LN), that can be RPL routers
of leaves.
She, et al. Expires 21 June 2021 [Page 2]
Internet-Draft DODAG size December 2020
The PAN formation process starts from a DODAG Root. Before a node
joins a PAN, it has no information regarding available neighbors or
PANs. To discover available PANs, a joining node transmits PAN
Advertisement Solicits and listens for PAN Advertisements from either
Show full document text