Unstrung Feature

Unstrung is an implementation of the IETF ROLL Working Group's RPL - RFC6550 routing protocol. RPL is pronounced Ripple.

Mesh-over networking

RPL is a mesh-over routing protocol. This means that it can run over a variety of different media: 802.11, ethernet, 802.15.4, Bluetooth, SLIP, PPP, etc. It groups a set of diverse links into a single logical (layer-3) subnet.

IPv6 - Internet of Things

RPL is targetted at IPv6, to Internet of Things deployments: Low-power and Lossy Networks (LLNs). RPL is very byte and battery efficient.

Linux gateways

The Unstrung implementation is not intended for the sensors, but rather for the gateway systems, and the wired/ethernet backhaul networks. It can also run in access points, in bigger multipurpose IoT nodes, and in laptops and other diagnostic devices.


Ripple is also a Grateful dead song, and the name "Unstrung", and the name of the daemon, "sunshine" are taken from the song.

If my words did glow with the gold of sunshine
And my tunes were played on the harp unstrung,
Would you hear my voice come through the music?
Would you hold it near as it were your own?

It's a hand-me-down, the thoughts are broken,
Perhaps they're better left unsung.
I don't know, don't really care
Let there be songs to fill the air.

Ripple in still water,
When there is no pebble tossed,
Nor wind to blow.

Reach out your hand if your cup be empty,
If your cup is full may it be again,
Let it be known there is a fountain,
That was not made by the hands of men.

There is a road, no simple highway,
Between the dawn and the dark of night,
And if you go no one may follow,
That path is for your steps alone.

Ripple in still water,
When there is no pebble tossed,
Nor wind to blow.

You, who choose to lead, must follow
But if you fall you fall alone.
If you should stand then who's to guide you?
If I knew the way I would take you home.


Unstrung is hosted on github.com

Version 1.10 was released on October 19, 2015. See CHANGELOG. You can download it here or from github.

Once tested, an ipkg for OpenWRT/RAMIPS is will be available here, or build your own

At this point in development, neither RPM, DPKG, iPKG (openwrt) nor APK (Android) are available, but all are planned


Some unit testing is done by Travis-CI


To report issues please use the github issue tracker

For support contracts, please contact sales@sandelman.ca

Project planning is by CREDIL at http://code.credil.org/projects/unstrung.

Mailing List

A mailing lists exists: unstrung-workers-request@lists.sandelman.ca, subscribe via mailman.

The archives are at: http://lists.sandelman.ca/pipermail/unstrung-hackers/.


Contiki contains a ROLL RPL implementation, and is oriented to sensors. It also has a Google Plus community

Other implementations

As described in this article, there are two other implementations of RPL for Linux. linux-rpl lives in kernel, and SimpleRPL.

IETF Working Group

The IETF ROLL Working is for protocol and interoperability issues.

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