On Sun, 30 Jan 2005 23:39:25 GMT, "Eras" <(E-Mail Removed)> wrote:
>Anyone know of a really good hard copy source (i.e., book) that is an
>excellent reference for wireless 802.11 network configurations?
Most printed books are at least 1-2 years out of date.
>I'd really
>like something that shows various topologies and configurations to impliment
>them
See:
http://www.ydi.com/deployinfo/system-diagrams.php
The topologies shown revolve around the YDI product line, but cover
most (not all) possible configurations. Note that a mixed
infrastructure/bridge WDS network is not shown, which is becoming all
too common. Same with a mesh network and an ad-hoc network.
Mesh and ad-hoc network topologies are essentially similar and appear
to be somewhat arbitrary and random. Well, actually, they are
arbitrary and random. Kinda difficult to draw a sane topology
diagram. See:
http://www.pdos.lcs.mit.edu/roofnet/map.php
for a typical example. Any semblance to spaghetti is strictly
coincidental. The major distinction is the mesh network routing
protocol.
>-- and also includes a nice glossary of definitions, IEEE standards,
>procedures, etc.
IEEE standards:
http://standards.ieee.org/getieee802/index.html
Note that they do not post proposed standards and standards in
progress.
802.11 Data frames and such:
http://www.wi-fiplanet.com/tutorials...le.php/3442991
Follow the various links for details.
There are many glossaries that include wireless terms, acronyms, and
buzzwords on the web. However, most offer only one line definitions,
with little detail. If you run into a non-obvious term, I suggest
just using Google to search for an explanation.
Wireless Security:
http://www.drizzle.com/~aboba/IEEE/
>My googles have been leading mainly towards just very specific (and often,
>unrelated) material to manufacturer knowledge bases, which more than often
>lead to more confusion than answers.
Some manufacturers databases, marketting hype, and buzzword
manufacturing is intended to confuse rather than clarify. Do you get
driving lessons from your autombile manufacturer or dealer? Your best
sources are the various tutorials, white papers, product data sheets,
and hated power point presentations by the various chip manufacturers
(Broadcom, Atheros, etc) which are intended to educate the panic
stricken neophyte engineer stuck with delivering a working product
before the traditional unrealistic deadline.
http://www.atheros.com/pt/papers.html
http://www.broadcom.com/products/cat...category_id=40
There are web review and test web sites with advertising cluttered
tutorials, but worth reading:
http://www.tomsnetworking.com/NeedToKnows.php
http://www.smallnetbuilder.com/FAQ.php
>Here is where the
>headaches begin.
>Couldn't find answers to questions that may be obvious (i.e., does the
>repeater need encryption on to repeat or is it just a "garbage in, garbage
>out" device in repeater mode, which modes such as Super/Turbo can be
>repeated, in "repeater mode" is DHCP still funneled from router, etc.)
>Eventually figured out answers to all those questions, but not until after
>hours of trial-and-error.
My domain is LearnByDestroying.com for obvious reasons. Some things
are best learned by experience.
>I still haven't been able to figure out if both
>802.11a and 802.11b/g can be simultaneously repeated. I can report one or
>other, but when I try both it locks up.
What is "it"? What locks up? Can you ping the various boxes
involved?
>In 20 years of using computers, I
>had to make my first ever calls to a technical support line -- and even
>they, althought I do have to say they were very friendly and commited to
>trying to help, didn't really know if both could be repeated. Get different
>answers depending on who you talk to. Crazy.
Simple economy. Tech support has become an entry level position years
ago. If they knew what they were doing, they wouldn't be doing tech
support. It's also difficult for anyone on the phone to answer
questions about systems they've never seen or worked with. How much
hands-on hardware time do you think they get in support. In my never
humble opinion, experience is more important than access to the
internal knowledge base. However, experience is expensive.
The reason you're getting different answers is not because of
different individuals. It's because operation of the knowledgebase is
dependent upon the selection of the appropriate buzzwords. Each
person on the phone will tend to select a different assortment of
buzzwords to pound into the search engine. Of course, results will
vary. In addition, they are usually not allowed to guess, or offer
advice which is not in the database.
>If a function isn't capable
>in a certain situation, why didn't they have the configuration program just
>grey-it out?
It would also be nice if the useless and excessively over-simplified
data sheets and product specifications detail such things. Yeah,
you're correct. Now, imagine the multitude of configurations that one
can assemble a wireless network using repeaters, WDS, bridging, and
mixed mode radios? All the combinations and permuations should be
tested, but often one is missed. More likely, the engineering
specification indicated that it should be possible to do a mixed mode
repeater (which is why it's not grayed out), but someone either forgot
to test it or some manager decided that it wasn't important, or could
be fixed in the next inevitable firmware release. Meanwhile, you fall
into the trap.
>That would save headaches. From my deja searches, seems
>Linksys is not really much better off in this department as well.
DLink, Linksys, and Netgear are all bottom of the line vendors. One's
expectations should generally follow the price tag.
>Hence, why I would like such a book. Also would nice to see how PtP and
>PtMP bridging actually works. Documentation and KB leave much confusion on
>these as well.
Well, you'll find quite a bit on Point to Point and Point to
Multipoint protocols in the various IEEE 802.11 specifications. It's
rather rough reading. Pay attention to the contents of the management
frames, which run the show. However, the IEEE 802.11 specs idea of
point to point is NOT a transparent (workgroup) bridge, but a single
MAC address wireless bridge. Point to mutlipoint is called
infrastructure mode.
However, you'll find very little on proprietary implimentations such
as Super-G, Turbo-G, and such. You will also have difficulty finding
specifics on WDS (wireless distribution system), and repeater mode,
which are similar, but proprietary to the chip manufacturers. I've
found that reading the WDS code for the various open source WRT54G
firmware to be the best source of detail. Also lacking in the 802.11
specifications is any protocol for transparent bridging, which also
tends to be proprietary by chip manufactory. The thing to remember
when reading all this stuff is that everything in 802.11 happens on
the MAC layer (Layer 2) and the IP address features are just along for
the ride.
Good luck...
--
Jeff Liebermann
(E-Mail Removed)
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558
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