Mesh test at scale

[Javier Cardona]

2009/3/5 Brian DeLacey <bdelacey at gmail.com>:
> Thanks, Javier ... I'll have to figure out how to use that ...
>
> Is it legit to set up the routing parameters and then use ping results as a
> measure? That gives us good information on packets transmitted, received,
> and packet loss as well as rtt min/avg/max/mdev.

Yes, sure.

Javier

> Brian
>
>
> On Thu, Mar 5, 2009 at 5:56 PM, Javier Cardona <javier at cozybit.com> wrote:
>>
>> Brian,
>>
>> 2009/3/5 Brian DeLacey <bdelacey at gmail.com>:
>> > Is there any command line program / info that will tell average number
>> > of
>> > hops at reception without instrumenting code?
>>
>> Not directly, but you might be able to infer it from the stats exposed
>> via debugfs:
>>
>> debugfs_netdev.c:
>>        MESHSTATS_ADD(fwded_frames);   <<<<<
>>        MESHSTATS_ADD(dropped_frames_ttl);
>>        MESHSTATS_ADD(dropped_frames_no_route);
>>        MESHSTATS_ADD(estab_plinks);
>>
>> Cheers,
>>
>> Javier
>>
>>
>> > On Thu, Mar 5, 2009 at 12:45 PM, Javier Cardona <javier at cozybit.com>
>> > wrote:
>> >>
>> >> Hi Brian,
>> >>
>> >> 2009/3/5 Brian DeLacey <bdelacey at gmail.com>:
>> >> > I have an opportunity to install mesh points on 16 - 25 fresh
>> >> > machines
>> >> > in a
>> >> > data center (this weekend).
>> >>
>> >> That's great!  That's bigger than our testbed, so I'm eager to see your
>> >> results.
>> >>
>> >> > Are tests worth running at this scale? What functionality should the
>> >> > tests
>> >> > cover?
>> >>
>> >> Certainly.  Some interesting tests (some require some
>> >> coding/instrumentation, though)
>> >>
>> >> 1.  Coverage,RTT as a function of the number of peers.
>> >>
>> >> Set the maximum number of peers on each node to N
>> >> (mesh_max_peer_links), N
>> >> > 1.
>> >> Set the mesh ttl (mesh_ttl) to be equal or higher than the total
>> >> number of nodes in your mesh.
>> >> Run a script on each node to ping all other nodes in a round robin
>> >> fashion.
>> >> Record the  round trip time and losses.
>> >> Record the avg. number of hops at reception (this requires adding
>> >> instrumentation code to the stack).
>> >>
>> >> As N decreases, longer routes will have to be used between any two
>> >> nodes in the mesh.  This will stress route discovery.
>> >>
>> >> 2.  Path recovery time.
>> >>
>> >> Using iw dev mesh station $HW_ADDR set plink_action block, force
>> >> multi-hop routes through known nodes.
>> >> Ping through a multihop path.
>> >> Measure the effects in the RTT of breaking paths.
>> >>
>> >> 3.  Throughput as a function of hops.
>> >>
>> >> It is easy to create paths of arbitrary length by blocking peers
>> >> and/or disabling mesh_auto_open_plinks.
>> >> With iperf, measure the throughput as a number of hops.
>> >> You should be getting the familiar 1/n curve for single channel mesh.
>> >>
>> >> That should keep you busy over the weekend... ;)
>> >>
>> >> Cheers,
>> >>
>> >> Javier
>> >>
>> >>
>> >> --
>> >> Javier Cardona
>> >> cozybit Inc.
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>> >> Devel at lists.open80211s.org
>> >> http://open80211s.com/mailman/listinfo/devel
>> >
>> >
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>> >
>>
>>
>>
>> --
>> Javier Cardona
>> cozybit Inc.
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-- 
Javier Cardona
cozybit Inc.