Technical Summary
Low power and Lossy Networks (LLNs) have specific routing
characteristics compared with traditional wired or ad-hoc networks
that have been spelled out in [RFC5548], [RFC5673], [RFC5826] and
[RFC5867]. These involve selecting routes that optimize for particular
metrics under non-trivial constraints.
Historically, IGP such as OSPF ([RFC2328]) and IS-IS ([RFC1195]) have
used quantitative static link metrics. Other mechanisms such as
Multiprotocol Label Switching (MPLS) Traffic Engineering (TE) (see
[RFC2702] and [RFC3209]) make use of other link attributes such as
the available reserved bandwidth (dynamic) or link affinities (most
of the time static) to compute constrained shortest paths for Traffic
Engineering Label Switched Paths (TE LSPs).
This document specifies routing metrics and constraints to be used in
path calculation by the Routing Protocol for Low Power and Lossy
Networks (RPL) specified in [I-D.ietf-roll-rpl]. It propose a flexible
mechanism for the advertisement of routing metrics and constraints
used by RPL. Some RPL implementations may elect to adopt an
extremely simple approach based on the use of a single metric with no
constraint whereas other implementations may use a larger set of link
and node routing metrics and constraints. This specification
provides a high degree of flexibility and a set of routing metrics
and constraints, including node state and attributes, node energy,
hop-count, estimated transmission count, throughput, latency, link
reliability, mode of operation, or generic 'color'. Extensions are
anticipated should ew routing metrics and constraints be
defined in the future.
Working Group Summary
No issues. It took several iterations before we had a solid technical
document.
Document Quality
Good quality. It is basically defining a type representation, so
implementation is trivial.
Personnel
David Culler (culler@eecs.berkeley.edu) is the Document Shepherd.
Adrian Farrel (adrian.farrel@huawei.com) is the Responsible AD.