Re: What is SAM value? "ieee802154 phy0 wpan0: SAM value 0x3 not supported"

[Alexander Aring <alex.aring@gmail.com>]

On Mon, Jul 27, 2015 at 12:52:42PM +0200, Baptiste Clenet wrote:
> 2015-07-27 12:38 GMT+02:00 Alexander Aring <alex.aring@gmail.com>:
> > On Mon, Jul 27, 2015 at 12:31:28PM +0200, Baptiste Clenet wrote:
> >> 2015-07-27 12:21 GMT+02:00 Alexander Aring <alex.aring@gmail.com>:
> >> > On Mon, Jul 27, 2015 at 12:08:18PM +0200, Baptiste Clenet wrote:
> >> > ...
> >> >>
> >> >> Receiving side:
> >> >> [  176.921637] CID flag is set, increase header with one
> >> >> [  176.931640] NH flag is set, next header carried inline: 02
> >> >> [  176.942502] SAC bit is set. Handle context based source address.
> >> >> [  176.954397]
> >> >> [  176.957352] ieee802154 phy0 wpan0: SAM value 0x3 not supported
> >> >>
> >> >
> >> > Yes this is not what it was transmitted before from the other node.
> >> > That's why I would ask for some sniffing device, somewhere in the lower
> >> > layers mac or phy it will fill your frame with garbage.
> >> >
> >> > I can't tell you now if it's the transmitted node or the receiving node.
> >> > You need to debug it there.
> >> Yeah, I agree.
> >>
> >> >
> >> > To ensure the transmitted node don't send garbage I would like to check
> >> > it with some sniffer device. If you see garbage on the sniffer device
> >> > then it's something wrong with the transmitting.
> >> Ok, but I did sniffing with monitor0 on the receiver as I mentioned earlier.
> >> How may I sniff a packet ont the sender? Because I can't set up
> >> lowpan0 on top of monitor0.
> >> How may I sniff on lower layers?
> >>
> >
> > In short:
> >
> > Monitor is just for sniffing, we don't parse any payload data on it. You
> > can't create a lowpan interface on it, please use the L2 interface
> > (wpan0). See [0], you maybe need a third node which running as monitor.
> 
> I don't think I've got it, you want me to set up a network of 3 nodes with:
> 1            2             3
> sender   receiver    receiver
> wpan0    wpan0      monitor0
> 
> But I will see exactly the same things as earlier.

You can save the dump (e.g. tshark I think with -w $FILE) somewhere or
doing pipe via ssh, refer [0].

I don't know what "But I will see exactly the same things as earlier" I
don't know now if the sender transmit correct things and the receiver do
some garbage then OR the sender already transmit incorrect data.

When you have such dump file you can easily open this dump with
wireshark, wireshark will autodetect the 6LoWPAN header then from the
wpan interface and shows "hopefully" correct 6LoWPAN decompressed data
(IPv6) which should be the same like what lowpan interface shows.

> And I won't sniff phy layer.
> 

Yes, we all don't want to decode the phy layer manually. :D I don't have
the equipment and knowledge for doing this.

- Alex

[0] http://wpan.cakelab.org/#_sniffing