[Olsr-users] [B.A.T.M.A.N.] point me to some OSI layer diagrams if possible ?

[L. Aaron Kaplan]

(CCing the OLSR list, since George also asked the same question there but got no answer yet)

On Dec 9, 2009, at 9:42 PM, George Sanders wrote:

> I am researching meshes/MANETs, and the accompanying 802.11s/HWMP/olsr/etc.
> 
> Before asking any specific questions, I wonder if someone could point me to some proper OSI
> diagrams that I cannot find - specifically:
> 
> 

ok, here is my attempt.....

+--------------+
| Application  |  7
+--------------+
| presentation |  6    E_DOES_NOT_REALLY_EXIST 
+--------------+
| session      |  5    E_DOES_NOT_REALLY_EXIST
+--------------+
| transport    |  4
+--------------+-----------------------------+
| IP, OLSR.org, B.A.T.M.A.N layer 3 version  |  3    OLSR.org's OLSR implemenation is located here
+-------------------------------------------------------------+
| link, 802.11s, B.A.T.M.A.N  layer 2 version, OLPC's  802.11s|  2    the HWMP and all the 80.211s stuff resides here. 802.11a/b/g/n resides here. Madwifi, ath5k and ath9k reside here. There is massive room for improvement on the Wi-Fi level!
+--------------------------------------------+----------------+
| phy                                        |  1    this part of the stack is definitely a problem for any routing protocol [*]
+--------------------------------------------+



[*] Much of the discussion focuses on "protocol $bla is better than $foo" but actually the Wi-Fi layer 2 and 1 could need massive improvements!  It is not the routing protocol on higher levels which matters. Wi-Fi per se was not intended to scale so high as we use it in community Wi-Fi networks :)
In case layer 1 and 2 were very good and stable, we would be able to run almost any protocol on top .





> 
> - can someone draw, or direct me to, an OSI diagram showing an 802.11a/b/g/n network using 
> plain old vanilla 802.11s + HWMP (no OLSR) to support an IP network ?
> 
> 
> 
> Then, for comparison:
> 
> 
> 
> - can someone draw, or direct me to, an OSI diagram showing an 802.11a/b/g/n network using
> ONLY BATMAN (no 802.11s) ... ?
> 
> 
Have to ask back: which version do you mean? 

Please see: http://www.open-mesh.net/wiki/BranchesExplained


> 
> Finally, in my research I came across this very interesting conversation from 2006:
> 
> http://www.ietf.org/mail-archive/web/manet/current/msg08218.html
> 
> and I wonder, has that question:
> 
> "I agree, but we may still be able to pull it off without having to messup the stack."
> 
> been answered yet ?  Or is there still argument over whether or not some implementations require "discussion"
> between components on different OSI layers ?
> 

In my personal opinion, the more we can get *standardized* "hints" from the lower layers (especially Wi-Fi), the better any routing metric can become.
In OLSR.org the metric calculations were offloaded to a plugin architecture so you are quite free in this respect. I guess there is something similar in some versions of B.A.T.M.A.N. and I am sure people on the BATMAN list can actually answer this question better than me.


> Thank you.
> 

I hope it helped somewhat.

a.


PS: typing B.A.T.M.A.N. with all the "." dots all the time is... tiring. How about renaming it to "Span"? What came out of that discussion?