[Ns-developers] 802.11s code review

[Ruben Merz]

Dear Pavel, Gustavo


On 3/16/09 6:34 PM, Gustavo Carneiro wrote:
> 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).

Yep, I agree too. There should be a clear distinction between what is 
really standard compliant (i.e. defined in the standard) and what is (a) 
inferred from the standard because it was not clearly defined in the 
standard (b) research stuff.

 From my point of view, this distinction should be made clear in the 
code (though I don't have a clear idea how) and in the documentation.

Ruben


> 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,
>