Linux WPAN and Contiki NG

Linux WPAN and Contiki NG

[Marek Küthe]

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Hello dear Mailling list,

I would like to try Linux WPAN with Contriki NG and have some questions
(I am new to the topic, so the questions may be quite stupid): Contiki
NG, as I understand it, implements various 6lowpan standards -
including 6TiSCH, TSCH and 6TOP. Which of these are also implemented in
Linux WPAN and how can they be used? As I understand it, TSCH is
implemented. Is that correct? The use of it is explained on
https://linux-wpan.org/documentation.html.
Is there anything special I need to consider when connecting Linux and
Contiki NG?

I hope it's okay if I post my questions here on the Mailling list.

Greetings
Marek Küthe

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Re: Linux WPAN and Contiki NG

[Stefan Schmidt]

Hello Marek,

On 08.01.24 18:09, Marek Küthe wrote:
> Hello dear Mailling list,
> 
> I would like to try Linux WPAN with Contriki NG and have some questions
> (I am new to the topic, so the questions may be quite stupid): Contiki
> NG, as I understand it, implements various 6lowpan standards -
> including 6TiSCH, TSCH and 6TOP. Which of these are also implemented in
> Linux WPAN and how can they be used? As I understand it, TSCH is
> implemented. Is that correct?

I fear none of these advanced mechanisms (mostly for packet scheduling) 
are implemented. Linux wpan offers the basics in 802.15.4 and 6lowpan. 
PHY and MAC access and encapsulations and compression with 6lowpan.

  The use of it is explained on
> https://linux-wpan.org/documentation.html.
> Is there anything special I need to consider when connecting Linux and
> Contiki NG?

I have not looked at Contiki in years to be fair. In general the main 
1.4 and 6lowpan communication should work. If you enable advanced 
techniques for packet scheduling and timing you will surely run into 
problems. Would be happy to hear findings when you tried it. :-)

> I hope it's okay if I post my questions here on the Mailling list.

Its the perfect place for them. :-)

regards
Stefan Schmidt

Re: Linux WPAN and Contiki NG

[Michael Richardson]

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Marek Küthe <m-k-mailling-list@mk16.de> wrote:
    > I would like to try Linux WPAN with Contriki NG and have some questions
    > (I am new to the topic, so the questions may be quite stupid): Contiki
    > NG, as I understand it, implements various 6lowpan standards -
    > including 6TiSCH, TSCH and 6TOP. Which of these are also implemented in

As Stefan said, you can not yet run TSCH on Linux.
Many of us would like to make it happen, and a few (Alex!) are writing code,
but there hasn't been a resources to allow anyone to spend real time on it.
Typically, people combine a Linux host (like a openwrt router) with a USB
connection to a Contiki or RIOTOS (or maybe Zephyr now) device that acts as
the 6TISCH device.


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Re: Linux WPAN and Contiki NG

[Marek Küthe]

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On Tue, 9 Jan 2024 08:34:47 +0100
Stefan Schmidt <stefan@datenfreihafen.org> wrote:

Thanks for the answer!

> Would be happy to hear findings when you tried it. :-)

I have written a small blog entry about my configuration. It may not be
particularly beautiful (written) - but I think you can understand it.

TLDR: Linux and Contriki NG only work together when Contriki NG is in
CSMA mode.

English: https://mk16.de/blog/contiki-ng-linux-wpan-6lowpan-en/
German: https://mk16.de/blog/contiki-ng-linux-wpan-6lowpan-de/

-- 
Marek Küthe
m.k@mk16.de
er/ihm he/him

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Re: Linux WPAN and Contiki NG

[Marek Küthe]

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On Tue, 09 Jan 2024 08:57:09 -0500
Michael Richardson <mcr@sandelman.ca> wrote:

> As Stefan said, you can not yet run TSCH on Linux.
> Many of us would like to make it happen, and a few (Alex!) are writing code,
> but there hasn't been a resources to allow anyone to spend real time on it.
> Typically, people combine a Linux host (like a openwrt router) with a USB
> connection to a Contiki or RIOTOS (or maybe Zephyr now) device that acts as
> the 6TISCH device.
> 

Thanks for the answer! However, when I create a new wpan0 interface,
`coordinator` also appears for choice. Is this not TSCH related?

```
$iwpan phy7 interface add test type
Usage:	iwpan [options] phy <phyname> interface add <name> type
<type> [extended address <hex as 00:11:..>]

Add a new virtual interface with the given configuration.
Valid interface types are: node, monitor, coordinator.



Options:
	--debug		enable netlink debugging
```

-- 
Marek Küthe
m.k@mk16.de
er/ihm he/him

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Re: Linux WPAN and Contiki NG

[Alexander Aring]

Hi,

On Tue, Jan 9, 2024 at 1:36 PM Marek Küthe <m-k-mailling-list@mk16.de> wrote:
>
> On Tue, 09 Jan 2024 08:57:09 -0500
> Michael Richardson <mcr@sandelman.ca> wrote:
>
> > As Stefan said, you can not yet run TSCH on Linux.
> > Many of us would like to make it happen, and a few (Alex!) are writing code,
> > but there hasn't been a resources to allow anyone to spend real time on it.
> > Typically, people combine a Linux host (like a openwrt router) with a USB
> > connection to a Contiki or RIOTOS (or maybe Zephyr now) device that acts as
> > the 6TISCH device.
> >
>
> Thanks for the answer! However, when I create a new wpan0 interface,
> `coordinator` also appears for choice. Is this not TSCH related?
>

no, it's not TSCH related. You can probably have a tun interface and
speak with a contiki co-processor to forward raw IPv6 from/to a
contiki device. Google keyword is "slip", but then you don't use any
of Linux 802.15.4 or 6LoWPAN functionality.

If you use 802.15.4 contiki without TSCH or what we at least support
"legacy devices", be sure you disable ContikiMAC which is an
out-of-spec duty contiki specific duty cycle thing.

- Alex

Re: Linux WPAN and Contiki NG

[Stefan Schmidt]

Hello Marek,

[I added the list back into cc as I think is could be of interest to 
more people. Also your blog post for people interested in trying out 
Contiki NG with Linux]

On 09.01.24 19:32, Marek Küthe wrote:
> On Tue, 9 Jan 2024 08:34:47 +0100
> Stefan Schmidt <stefan@datenfreihafen.org> wrote:
> 
>> Would be happy to hear findings when you tried it. :-)
> 
> I have written a small blog entry about my configuration. It may not be
> particularly beautiful (written) - but I think you can understand it.
> 
> TLDR: Linux and Contriki NG only work together when Contriki NG is in
> CSMA mode.
> 
> English: https://mk16.de/blog/contiki-ng-linux-wpan-6lowpan-en/
> German: https://mk16.de/blog/contiki-ng-linux-wpan-6lowpan-de/

Thanks, it was a good read.

To address some of your implicit questions in the post. Yes, the first 
missing pings could be due to ND. To be sure you would need to check out 
the packets with wireshark or similar.

As for the MAC access mode needed to be CSMA, yes this is the only one 
supported. The biggest problem, for Linux, with other modes like 6Tisch 
is the hard timing requirements. If it is possible to work in these 
real-time requirements would have to be tested. Nobody stepped up to do 
the implementation yet to try it out.

One could start with simple implementation, if that fails, make use of 
preempt-rt features, if that fails see what hardware timers or other 
capabilities of the transceivers could be used. On the ATUSB, time 
critical pathes could also be offloaded into the firmware.

It all depends on interest, motivation and time :-)

regards
Stefan Schmidt