[Ns-developers] 802.11s code review

[Gustavo Carneiro]

2009/3/16 Pavel Boyko <boyko at iitp.ru>

>  Gustavo,
>
> On Monday 16 March 2009 19:07:25 Gustavo Carneiro wrote:
> > I am still no following.  I thought a .11s MAC layer would have its own
> > private instance of a routing agent.  Why would you have one routing
> agent
> > managing more than one .11s card?  Is that described in the .11s draft,
> or
> > any other standard?
>
> No, unfortunately 11s draft doesn't describe coordinated operation of the
> several wireless interfaces on the single mesh point. However, single
> interface mesh points don't look promising for our needs, you can find some
> very basic discussion even here:
> http://en.wikipedia.org/wiki/History_of_wireless_mesh_networking
>
> So we have decided to extend 11s draft model from the very start. One can
> obviously use single interface configuration in your simulation if you wish
> to
> exactly follow 11s.
>
> The way we propose to model multi-interface mesh point is really very
> similar
> to 'plain' bridging. The main difference is that our virtual mesh point
> device
> can (and do) _change_ packets it forwards from/to its interfaces, e.g.
> adding
> routing information. We don't subclass (and even use) BridgeNetDevice for
> this
> reason (using, however, BridgeChannel class).


Not saying what you are doing is wrong, but in my opinion we shouldn't
indistinctly mix code implementing a standard with code implementing a
research architecture.  Maybe it's just me, but I find it just too confusing
(as evidenced by the number of emails I had to send to clear my doubts).

In my humble opinion, it would be much better if multi-interface support was
completely separate from .11s, and be conceptually "above" the netdevice.
In a different module, even.  Refactoring the 'src/devices/bridge' module to
support mesh bridging could be an option, I think.  At least I don't see
anything wrong with it in principle...

Regards,

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert