in Higher Ed]
On Tue, Apr 01, 2008 at 08:25:06AM -0400, Dave Molta wrote:
> I agree with Chuck about the need for better information about WLAN
> scalability. It's an issue I've struggled with for many years but I'm not
> optimistic about a resolution. I've discussed thi
I agree with Chuck about the need for better information about WLAN
scalability. It's an issue I've struggled with for many years but I'm not
optimistic about a resolution. I've discussed this issue extensively with
Phil Belanger, the author of the Novarum report, and I just can't see any
way to ge
I think Peter has the right perspective here. The risk that a Draft
2.0/Wi-Fi Certified AP purchased today would be incompatible with the final
standard is quite low. However, the likelihood is high that an 11n AP
purchased a year from now, based on second or third-generation 11n silicon,
will prov
These are good points. Your observation that all but the lowest-end
notebooks ship with 11n is fairly consistent with my own observations. In
fact, I don't know whether Intel even offers a new Centrino solution that
doesn't include the 3945 abgn adapter. That fact, along with the Wi-Fi
Certificatio
TED]
> Sent: Thursday, June 14, 2007 11:59 AM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] Cisco vs. Meru article
>
> On Jun 14, 2007, at 10:24, Dave Molta wrote:
>
> > Just to elaborate a bit, the article James sent around was not the
> &g
Just to elaborate a bit, the article James sent around was not the original
Meru-Cisco feature story but rather a column that reports on results of
subsequent testing. In this column, I reported three things. First, Cisco
was unsuccessful in getting the Wi-Fi Alliance to rescind Meru's
certificatio
The Meru "good-neighbor" issue involves some
technical questions about how Meru uses the duration field of 802.11, which
provides virtual carrier sense. Although I am a little disappointed that Cisco
is trying exploiting this issue through their sales channel (I bet less
than 5% of Cisco sal
> >allow APs to go both ways. APs that need to decrypt and then tunnel
> >the data to the controller for further direction should be
> able to do
> >this. APs that tunnel everything back (for decrypt) should
> be able to
> >do this as well. But, as we have seen in
I personally feel that traditional FAT AP's can be made
to work effectively, even in large environments, but it requires a considerable
amount of integration and more staff expertise than controller-based systems. In
addition, since the industry as a whole is clearly moving towards the contro
John,
I think there are excellent applications for AMP in University environments,
especially those that have to manage multiple generations of AP's or AP's
from multiple vendors. Clearly, it's possible to implement and run a very
large .edu network without buying into one of the new controller-ba
Some thoughts about Cisco wireless from a guy who used to manage large .edu
networks but now mostly analyzes, teaches and writes about it:
Ever since Symbol rolled out the first wireless switch, I've tried to remain
mostly agnostic about how much intelligence should reside in the AP versus
in cent
I personally have pretty strong feelings about this issue and feel some
frustation that too many organizations adopt a perspective of choosing
between 11a and 11g. My view is that supporting both 11a and 11g provides
you with more wireless capacity and better performance at only a modest
increase i
This is quite a can of
worms.
We just completed a WLAN
client test in our labs at Syracuse University, the results of which will be
published in Network Computing next month. I can't broadcast all of the detailed
results prior to publication, but I can tell you what we did and what we
dis
Title: Why 802.11 vs Wi Max or 3G or 4G
Lee,
We could write a book on the many issues involved, but the
bottom line here is that at least in the short term, these are not really
competitive technologies.
For some organizations with geographically mobile
workforces, the 3G solution is a g
Title: WIRELESS-LAN Digest - 17 Jan 2006 to 19 Jan 2006 (#2006-10)
We're about to do a bake-off here at Syracuse for an
upcoming issue of Network Computing Magazine. We're still finalizing our
test-plan, but from a performance standpoint, we plan to look at QoS,
roaming, load-balancing, failo
Clint,
I don't think there's anything like Vivato out there. The closest thing
might be the Xirrus WLAN Array, which is a multi-radio system with high-gain
sectorized antennas. It doesn't do beam-forming but it does provide extended
range using a single AP.
dm
> -Original Message-
> Fro
It's fairly easy to understand how the scheduling capabilities of Meru allow
it to maximize throughput and minimize latency using a single channel
throughout a building, but I still wonder about the aggregate capacity when
compared to a more traditional and well-implemented overlapping cell design
The other factor that shouldn't be ignored is the role that clients play in
contributing to co-channel interference issues in dense deployment WLANs.
It's relatively easy (albeit expensive) to design micro-cell AP
configurations that maximize per-user bandwidth by reducing power output on
the AP. H
I don't have a ton of hands-on experience with these
products so I can't provide much in the way of technical details but we are
currently looking at the Cognio and Berkely Varitronics (BVS) spectrum
analyzers in our Syracuse University lab. We've also had experience with
Avcom Ramsey, which
You may want to look at Frank Bulk's June, 2005 review of distributed
security monitoring systems, which included Airtight, AirMagnet, Air
Defense, Network Chemistry, and Highwall:
http://www.networkcomputing.com/showitem.jhtml;jsessionid=GTY031U43EMLQQSNDB
CSKH0CJUMEKJVN?docid=1612f2
These syste
At Syracuse, we are close to going live with a new web-based wireless access
portal that provides three levels of access:
1. Normal University users authenticate with their campus NetID and have
full access.
2. Anyone having a valid NetID can also provision a time-limited sponsored
guest accoun
s and easily project their screens wirelessly
to a room-based projection system. While some vendors offer these
capabilities, they're not really suitable for campus deployment.
Dave Molta
SU School of Information Studies
> -Original Message-
> From: Dewitt Latimer [mailto:[E
I wanted to thank everyone who provided valuable input, both publicly and
privately, regarding Network Computing's planned feature article on wireless
analysis tools.
To be honest, I was a little surprised that AMP was the most oft-mentioned
tool, but I think I understand why. While it's great to
are of a sensitive nature, you can e-mail me directly.
1. What are the most common WLAN problems you face, either in the design or
operation of your network, for which WLAN analysis tools might be helpful?
2. Which specific available tools -- commercial or otherwise -- are most
helpful in allowing
The performance degradation associated with mixing b and g on the network
varies depending on the mix of b and g traffic. I believe our recent tests
of b and g clients doing simultaneous file transfers through the same AP
showed an aggregate TCP throughput of around 12 Mbps. That's about twice
what
The other caveat here is that the Cirond testing was performed with older
Prism II chip sets from Intersil (now Conexant). My understanding is that
there were some unique properties of those chip sets that made them more
conducive to the 4-channel model and that this model is not as applicable to
m
Scott,
Frank Bulk put a fair amount of time into investigating the channel 11
issues in our test lab at Syracuse, using some gear from Azimuth as well as
some field testing in a faraday cage. We did find some issues, but they
didn't appear serious enough to warrant additional investigation and Cis
Since the issue of authentication has come up, I'm wondering how other
organizations are dealing with the guest access issue. Here at Syracuse,
we have an authentication system in place for wireless, web-based for
people who aren't concerned about session encryption and don't want to
deal with clie
issues listserv
[mailto:[EMAIL PROTECTED] On Behalf Of Dave Molta
Sent: Thursday, August 12, 2004 4:46 PM
To: [EMAIL PROTECTED]
Subject: Re: [WIRELESS-LAN] Rogue WAP's
Pierre,
I think you've got this one right. The best, and perhaps only, practical way
to eliminate rogues AP's on a Un
tever you choose, make sure it can scan all channels (US and
International) at both 2.4 GHz and 5 GHz. Also, be leary of solutions that
rely on clients to monitor since you can't always be assures that clients
will be on the network, especially after-hours when the hacking threat is
greatest.
Dave Molta
I think it's important to distinguish between analysis tools that rely
on commercial WLAN NICs and those that are based on calibrated RF
components. WLAN chip manufacturers freely admit that the RSSI signal
values reported up the stack of your notebook or PDA are as much as 3dBi
off the mark. So th
As some of you may know, the old Enterasys 11b NICs are OEM versions of
the old Lucent/Agere Orinoco NICs. Those cards were real work-horses --
very reliable, excellent receive sensitivity, and great driver support.
But like most 11b offerings, they are a legacy.
When Proxim bought the Orinoco pro
P.S. Turns out this was a web production error. We got it right in the
magazine and the problem will be corrected on the web site shortly.
dm
> -Original Message-
> From: 802.11 wireless issues listserv
> [mailto:[EMAIL PROTECTED] On Behalf Of
> Philippe Hanset
> Sent: Wednesday, April 07
eyond
vertical markets.
I also welcome ideas for article submissions, both for Network Computing
as well as Mobile Pipeline, which is a companion portal web site that
focuses on wireless issues. We're particularly interested in hands-on
stuff.
Dave Molta
Senior Technology Editor, Network
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