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From: seaweedsl on 7 Apr 2008 14:05
What Bill is saying, I think, is that as a network administrator, it's
often not efficient or appropriate for a local network to use B.
Your needs as an individual may be different, but you have to play
well with the group!

A big issue with B - and this is what you may be remembering from the
dorm - is that very few B cards can handle the newer WPA security.
In our system, for example, we use WPA (WEP is not secure) but one pc
with a B card only did WEP. It was not worth it to compromise the
security of the whole group just to let him on. We found him an
adapter.

I had an Orinoco classic B card that would do WPA security once I
found the proper firmware. There were 10 versions that did not do WPA
and one that did. So it's possible, just not likely.

If you need to travel and connect in various places, then you want
G.

Steve


From: msg on 7 Apr 2008 16:15
seaweedsl wrote:

<snip>
> A big issue with B - and this is what you may be remembering from the
> dorm - is that very few B cards can handle the newer WPA security.
> In our system, for example, we use WPA (WEP is not secure) but one pc
> with a B card only did WEP.

802.11b has distinct coverage advantages, and often greater channel
capacity in consumer-grade access points. No one should seriously
rely on embedded security in those products, WEP or WPA; a VPN
(IPsec for example) solution makes more sense and scales better
in a public (campus/dorm) setting.

Michael



From: mm on 7 Apr 2008 20:16
On Sun, 6 Apr 2008 22:11:19 -0400, "Bill Kearney"
<wkearney99(a)hotmail.com> wrote:

>>>Wireless "g" routers can be set to connect with "b" and "g" clients or "g"
>>>clients only. By default they communicated with both.
>>
>> That makes sense. I should have asked the guy at the dorm to turn on
>> b, if it was actually not on.
>
>If it's off then it should stay off. Why leave B running and burden the G
>network with having to take extra effort to handle the slower signal?

Maybe I should add that this dorm had about 37 people, maybe 10 of
whom had laptops, and probably no more than 5 were ever running at one
time. Plus they had on the same line a VOIP phone used less then an
hour a day, and 2 desk computers, each of them used less than an hour
a day. So the network was nowhere near its capacity.

I also take issue with the words "burden" and "extra effort". I know
it's common to anthropomorphise machines and electronics, but when
they don't really expend extra effort (or struggle, as I read
somewhere else). They do what they have the power to do, and if they
can't do all that is wanted, the slow down, or stop something. Maybe
sometimes they burn out, break, but that wouldn't happen in this
situation.

>
>Get a G-capable card. They're cheap enough.


If you are inclined to email me
for some reason, remove NOPSAM :-)
From: mm on 7 Apr 2008 20:22
On Mon, 7 Apr 2008 11:05:19 -0700 (PDT), seaweedsl
<seaweedsteve(a)gmail.com> wrote:

>What Bill is saying, I think, is that as a network administrator, it's
>often not efficient or appropriate for a local network to use B.
>Your needs as an individual may be different, but you have to play
>well with the group!

Maybe, but I knew this group personally, and we were all fraternal in
our attitudes to each other. Perhaps they were not technical enough
to realize that g could be running and b could run too if it was
turned back on, but if they had known that, they would have told me to
ask the guy who ran things.

But when they told me I needed g, I went out and got it. I don't
think I asked the network guy if that was what I should do, and I know
I didn't ask him if he could turn b back on. He never mentioned the
b-g issued.

Also, I don't think security was really an issue.

I was there for 7 weeks, but other people came and went. A few of them
with laptops. I won't be back any sooner than next March, and
probably not even then. But if I write him or talk to him, I hope I
ask him about all this.

Thanks for the technical stuff.

>A big issue with B - and this is what you may be remembering from the
>dorm - is that very few B cards can handle the newer WPA security.
>In our system, for example, we use WPA (WEP is not secure) but one pc
>with a B card only did WEP. It was not worth it to compromise the
>security of the whole group just to let him on. We found him an
>adapter.
>
>I had an Orinoco classic B card that would do WPA security once I
>found the proper firmware. There were 10 versions that did not do WPA
>and one that did. So it's possible, just not likely.
>
>If you need to travel and connect in various places, then you want
>G.



>Steve
>


If you are inclined to email me
for some reason, remove NOPSAM :-)
From: Jeff Liebermann on 7 Apr 2008 23:46
On Sun, 06 Apr 2008 15:33:13 -0400, mm <NOPSAMmm2005(a)bigfoot.com>
wrote:

>Does every wireless g router also transmit b?

The default is to enable 802.11b compatibility. I sometimes turn it
off.

The problem with "b" is not speed. It's the air time it occupies.
Data sent at 1Mbits/sec, the slowest 802.11b speed, occupies about 8
or 9 times as much air time as the same data sent at 6Mbits/sec, the
slowest 802.11g (OFDM) speed. If the airspace is saturated with a
large number of users, 802.11g can ideally handle 8 times as many
users, assuming they're running at the slowest speed (a good
assumption as multiple collisions will cause the access point to
switch to the slowest speeds in an attempt to recover).

There are other problems with 802.11b. With 802.11b compatibility
enabled in the wireless access point, all management packets and
broadcasts are sent at the slowest (and longest) 1Mbit/sec speed. Turn
off 802.11b compatibility, and 802.11g sends them at 6Mbits/sec, the
slowest 802.11g speed.

802.11b also has problems dealing with reflections, multipath, and
frequency selective fading. 802.11g OFDM modulation is far more
resistant to these problems. One would assume that this would not be
a common problem, but I'm finding it all too common.

For example, one of my coffee shop customers is in an octagon shaped
brick building. The place is one big mess of reflections. It's even
difficult to hear onself talk through all the noise and echos. I was
getting erratic download speeds and even some disconnects, for no
obvious reason. Monitoring the wireless router, I found far too many
users connecting at 802.11b speeds. I assumed that this was caused by
interference and reflections. So, I just turned off 802.11b
compatibility. The disconnects instantly ceased, and the erratic
performance was hugely reduced. So were the complaints.

I assumed that there would be problems with users having only 802.11b.
So, I hung up a small sign, under the "we have free wi-fi" sign, that
announced the 802.11b is not supported. There were a few complaints,
that I "solved" by explaining why they should buy a better wireless
adapter. There was also one issue that caught me by suprise. Many
802.11g USB dongles revert to 802.11b only mode if shoved into a USB
1.1 port. The device can easily do 802.11g speeds, but the authors of
the device drivers seem to think that flow control is evil, and that
the wireless speed should be slowed down to match the interface speed.
I can see the logic, but this has given me problems with some users.

There are also some PDA's that do not support 802.11g. For example,
my Verizon XV-6700 only does 802.11b, but does to WPA encryption.
There are other PDA's and cell phones with similar configurations.

At this time, some of my wireless routers have 802.11b enabled, while
others have it turned off. It varies by location, owner politics, and
class of users. If it's a high traffic and high user count system,
802.11b is OFF. If it's light use, then I leave it on.

--
Jeff Liebermann jeffl(a)cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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