2.6.14 Routing Over Low power and Lossy networks (roll)

NOTE: This charter is a snapshot of the 78th IETF Meeting in Maastricht, Netherlands. It may now be out-of-date.

Last Modified: 2010-08-23


JP Vasseur <jpv@cisco.com>
David Culler <culler@eecs.berkeley.edu>

Routing Area Director(s):

Stewart Bryant <stbryant@cisco.com>
Adrian Farrel <adrian.farrel@huawei.com>

Routing Area Advisor:

Adrian Farrel <adrian.farrel@huawei.com>

Technical Advisor(s):

Rene Struik <rstruik.ext@gmail.com>

Mailing Lists:

General Discussion: roll@ietf.org
To Subscribe: http://www.ietf.org/mailman/listinfo/roll
Archive: http://www.ietf.org/mail-archive/web/roll/

Description of Working Group:

Low power and Lossy networks (LLNs) are made up of many
embedded devices with limited power, memory, and processing
resources. They are interconnected by a variety of links, such as
IEEE 802.15.4, Bluetooth, Low Power WiFi, wired or other low
power PLC (Powerline Communication) links. LLNs are transitioning
to an end-to-end IP-based solution to avoid the problem of
non-interoperable networks interconnected by protocol translation
gateways and proxies.

Generally speaking, LLNs have at least five distinguishing
- LLNs operate with a hard, very small bound on state.
- In most cases, LLN optimize for saving energy.
- Typical traffic patterns are not simply unicast flows (e.g. in some
cases most if not all traffic can be point to multipoint).
- In most cases, LLNs will be employed over link layers with 
restricted frame-sizes, thus a routing protocol for LLNs should be
adapted for such link layers.
- LLN routing protocols have to be very careful when trading off
efficiency for generality; many LLN nodes do not have resources to 

These specific properties cause LLNs to have specific routing

Existing routing protocols such as OSPF, IS-IS, AODV, and OLSR have 
been evaluated by the working group and have in their current form been 
found to not satisfy all of these specific routing requirements.

The Working Group is focused on routing issues for LLN.

There is a wide scope of application areas for LLNs, including 
industrial monitoring, building automation (HVAC, lighting, access
fire), connected homes, healthcare, environmental monitoring, urban sensor
networks (e.g. Smart Grid), asset tracking. The Working Group focuses
on routing solutions for a subset of these: industrial, connected 
home, building and urban sensor networks for which routing requirements have
been specified. These application-specific routing requirement 
documents will be used for protocol design.

The Working Group focuses only on IPv6 routing architectural framework
for these application scenarios. The Framework will take into 
consideration various aspects including high reliability in the presence
of time 
varying loss characteristics and connectivity while permitting low-power 
operation with very modest memory and CPU pressure in networks
potentially comprising
a very large number (several thousands) of nodes.

The Working Group will pay particular attention to routing security 
and manageability (e.g., self routing configuration) issues. It will 
also need to consider the transport characteristic the routing protocol 
messages will experience. Mechanisms that protect an LLN from congestion
collapse or
that establish some degree of fairness between concurrent 
communication sessions are out of scope of the Working Group. It is
expected that
upper-layer applications utilizing LLNs define appropriate mechanisms.
The solution must include unicast and multicast considerations.

Work Items:

- Specification of routing metrics used in path calculation. This
includes static and dynamic link/node attributes required for routing in

- Provide an architectural framework for routing and path selection at
Layer 3 (Routing for LLN Architecture) that addresses such issues as
whether LLN routing require a distributed and/or centralized path
computation models, whether additional hierarchy is necessary and how it

Manageability will be considered with each approach, along with 
various trade-offs for maintaining low power operation, including the 
presence of non-trivial loss and networks with a very large number of nodes.

- Produce a routing security framework for routing in LLNs.

- Protocol work: The Working Group will consider specific routing 
requirements from the four application documents collectively, and
specify either 
a new protocol or extend an existing routing protocol in cooperation
with the 
relevant Working Group.
If requirements from the four target application areas cannot be met 
with a single protocol, the WG may choose to specify or extend more than
protocol (this will require a recharter of the WG).

- Documentation of applicability statement of ROLL routing protocols.

Goals and Milestones:

Done  Submit Routing requirements for Industrial applications to the IESG to be considered as an Informational RFC.
Done  Submit Routing requirements for Connected Home networks applications to the IESG to be considered as an Informational RFC.
Done  Submit Routing requirements for Building applications to the IESG to be considered as an Informational RFC.
Done  Submit Routing requirements for Urban networks applications to the IESG to be considered as an Informational RFC.
Feb 2009  Submit Protocol Survey to the IESG to be considered as an Informational RFC.
Apr 2009  Submit Security Framework to the IESG to be considered as an Informational RFC
May 2009  Submit the Routing for LLNs Architecture document to the IESG as an Informational RFC.
Jul 2009  Submit Routing metrics for LLNs document to the IESG to be considered as a Proposed Standard.
Done  Submit first draft of ROLL routing protocol specification as Proposed Standard.
Nov 2009  Submit first draft of the MIB module of the ROLL routing protocol specification.
Done  Submit the ROLL routing protocol specification to the IESG as Proposed Standard.
Mar 2010  Submit the MIB module of the ROLL routing protocol specification to the IESG as Proposed Standard.
Apr 2010  Evaluate WG progress, recharter or close.


  • draft-ietf-roll-terminology-04.txt
  • draft-ietf-roll-routing-metrics-09.txt
  • draft-ietf-roll-rpl-12.txt
  • draft-ietf-roll-of0-03.txt
  • draft-ietf-roll-trickle-04.txt
  • draft-ietf-roll-security-framework-01.txt
  • draft-ietf-roll-p2p-rpl-00.txt

    Request For Comments:

    RFC5548 I Routing Requirements for Urban Low-Power and Lossy Networks
    RFC5673 I Industrial Routing Requirements in Low Power and Lossy Networks
    RFC5826 I Home Automation Routing Requirements in Low Power and Lossy Networks
    RFC5867 I Building Automation Routing Requirements in Low-Power and Lossy Networks

    Meeting Minutes


    3) The Minimum Rank Objective Function with Hysteresis
    4) Routing Metrics
    5) The Trickle Algorithm
    6) Multicast Forwarding Using Trickle
    7) Reactive Discovery of Point-to-Point Routes
    RPL Update
    1+2+3- ROLL WG Meeting IETF 78