Re: Wireless N

[Paul Cychosz <pacychosz () wisc edu>]

Hi,

802.11n has no security enhancements.  It is purely high-throughput
enhancements (theoretical speeds of around 600mbps in it's best mode). 
Right now you can probably buy pre-n devices but it isn't worth it. 
There are 2 main proposals, TGn Sync, and WWiSE... but now they're
combining them into a Joint Group proposal (that will be probably
heavily sided towards TGn Sync since it got 74% of the last vote... 1%
more and it would have been chosen outright) that should be finished
some time very soon.  Basically, there are enhancements to the MAC and
PHY layer.  The mac layer implements some 802.11e stuff (QoS, block
ACKs, etc.) and aggregates several MSDU/MPDU (mac-layer frames) together
so it can send it out all at once, eliminating contention for the
wireless channel between frames.  There are some other things in the MAC
layer, but the general idea is that it removes overhead, allows multiple
recipients, header compression, 1 ACK for many frames, not having to
wait a DIFS be
tween frame transfers, etc.

The physical layer then uses MIMO (multiple antennas) to achieve higher
bandwidth.  Instead of using the traditional 20mhz per channel, they'll
have a mode that uses 40mhz of it.  I don't know what this means for
japan since there are laws against using more than 20mhz at a time (or i
think it's 18mhz actually).  Additionally, the phy-layer does something
called OFDM, something that 802.11a does already.  Basically, it just
splits up a radio signal into many narrowbands and them recombines them
at the source.  This coupled with aggressive FECs tries to defeat noise
in the environment.

see: www.tgnsync.org, www.wwise.org, and www.802wirelessworld.com
also, just look up the acronyms on wikipedia if you're interested.

paul


----- Original Message -----
From: Stephen Alford <stephena () sbspros net>
Date: Monday, November 21, 2005 7:20 pm
Subject: Wireless N
To: security-basics () securityfocus com

> Good day List members,
>
> I have a general query on whether the deployment of Wireless N (vs. 
> b/g) has
> any add'l security issues and/or is worth the extra expense of the 
> hardware.If anybody has experience with the new Wireless standard, 
> please could you
> post your feedback.
>
> Thanks in advance for your input.
>
>
> Stephen Alford, MCT, MCSE+Security, CCNA, CCDA, ASE
> Director, Partner Practices & Solutions, SBS Pros
> Email: stephena () sbspros net