Wireless N

S

Skeleton Man

Hi guys,

I'm looking at building a wired/wireless router from a spare P4 box I have,
and I'm thinking wireless N is the way to go. I was wondering though if the
nics are backwards compatible with A/B/G ?

Also, I'm thinking a seperate antenna would be best as the router will sit
out of sight and not atop my desk, etc. Could I just buy a couple of
omni-directional antennas and attach to the NIC ?

Another option I considered was a combination of a wired router and a good
access point (like Minitar, etc) to provide the wirless capability.

One last thing, is there any real performance difference in having only 2
two antennas vs 3 antennas ? From what I read only the two with the best
signal are used anyway right ?

Yes there are dozens of personal/home routers, but after the trouble I have
had with every one I've bought, I'm not going there (not unless they have
one with real ram and cpu - not some equivlent of a pentium 1 with 2 MB
ram).

Chris
 
D

DevilsPGD

In message <[email protected]> "Skeleton Man"
I'm looking at building a wired/wireless router from a spare P4 box I have,
and I'm thinking wireless N is the way to go. I was wondering though if the
nics are backwards compatible with A/B/G ?

Generally, yes. However, there are two totally separate bands, 2.4GHz
will support N/G/B, 5.8GHz supports N/A. I'm not aware of any hardware
on the market that allows both bands together.

Also consider that when you're in backward compatibility mode, you lose
out on most or all of the benefits that draft-N brings to the table.

While there is little harm in going with N, if you really want to get
the benefits of N, you will need to upgrade every device, or run two
different radios, one for N and one for B/G.
Another option I considered was a combination of a wired router and a good
access point (like Minitar, etc) to provide the wirless capability.

One last thing, is there any real performance difference in having only 2
two antennas vs 3 antennas ? From what I read only the two with the best
signal are used anyway right ?

As I understand it, that's correct. However, the advantage of three
antennas is that if signals bounce around, you are far more likely to
receive a reliable signal.

In the real world, whether you see a different or not probably depends
on the amount and type of interference in your area.
Yes there are dozens of personal/home routers, but after the trouble I have
had with every one I've bought, I'm not going there (not unless they have
one with real ram and cpu - not some equivlent of a pentium 1 with 2 MB
ram).

Indeed. I've been rather happy with pfSense as a firewall and router,
then a couple Airport Extremes deployed in appropriate locations (one in
5.8GHz N-only, and one in 2.4GHz N/B/G mode) for our users.
 
K

kony

Hi guys,

I'm looking at building a wired/wireless router from a spare P4 box I have,
and I'm thinking wireless N is the way to go. I was wondering though if the
nics are backwards compatible with A/B/G ?

Frankly if this will be kept running continuously, you'd be
better off buying a small all integrated board and CPU based
around a Via C3 or C7 or something similar as it will use
much less power, paying for itself in some reasonable period
of time (I'm too lazy to do the math but vaguely recall
Newegg and ClubIt both have at least one such board w/CPU
for $60 or less).

Typical NICs support only A, only B (if several years old),
or B/G if more recent. Some now also support N, if the
small cost difference is not important and considering the
purpose of the system I would pick one supporting B/G/N.

Do you really need a separate computer for this? Check out
DD-WRT firmware for wifi routers and which ones it supports,
you might be able to do this cheaper, using less
power/space/noise, and have the P4 box available for some
other use.

Also, I'm thinking a seperate antenna would be best as the router will sit
out of sight and not atop my desk, etc. Could I just buy a couple of
omni-directional antennas and attach to the NIC ?

Yes but there will be some loss from the cable. We dont'
know exactly what your needs are for this box, how much
control you need over the routing so it's hard to say what
to choose. A separate access point is one option, or if
you need a lot of control then a separate router and then
configure the P4 system as a firewall proxy.
Another option I considered was a combination of a wired router and a good
access point (like Minitar, etc) to provide the wirless capability.

You could do this, but what's wrong with a wireless router?

One last thing, is there any real performance difference in having only 2
two antennas vs 3 antennas ? From what I read only the two with the best
signal are used anyway right ?

That is correct AFAIK, though if antenna differences are
very important it could be that having a separate access
point located elsewhere is the way to provide best coverage,
and ideally that one connected over ethernet instead of
repeater to keep the airwaves free instead of halving the
throughput.

Yes there are dozens of personal/home routers, but after the trouble I have
had with every one I've bought, I'm not going there (not unless they have
one with real ram and cpu - not some equivlent of a pentium 1 with 2 MB
ram).


What trouble? A router does not need a lot of memory and
modern PC CPU - it just isn't a job requiring a lot of
memory and processing performance. Sometimes slow
performance is really just poor signal quality, that the
environment requires an additional access point or
directional antennas if there's a lot of background noise
from distant sources.

Two of the most common problems are overheating and buggy
firmware. Thus I suggested DD-WRT above and as needed, pop
open the router casing, epoxy a heatsink onto the networking
processor, and drill a few supplimental fan holes into the
casing. This can work very well and AFAIK everyone who
has done it prefers it to a separate computer doing the
routing - unless you need more control than the standalone
router provides in it's firmware, but DD-WRT also improves
upon the typical feature sets other firmware allows. My
router running DD-WRT has only gone down one time in more
than a year's use and then only because of an extended power
outtage. It is a Buffalo model no longer available due to
some kind of patent infringment issue (IIRC) but Linksys
WRT54GL is very similar, can also run DD-WRT.

There may be some 11n routers that can run DD-WRT too, you
might check out the DD-WRT forums where a lot of people
report and work through issues with specific routers. Even
if there are no issues I would still pop the top off, put a
heatsink on and drill more vent holes as it will also tend
to make the units last longer, preserving the capacitors by
keeping their temp lower.
 
S

Skeleton Man

Frankly if this will be kept running continuously, you'd be
better off buying a small all integrated board and CPU based
around a Via C3 or C7 or something similar as it will use
much less power, paying for itself in some reasonable period
of time (I'm too lazy to do the math but vaguely recall
Newegg and ClubIt both have at least one such board w/CPU
for $60 or less).

Are we talking like shuttle size integrated board ? If I can get what I need
cheap then I'd definately go that way (so it fits on my desk). I wanted
something that size initially, but I wasn't sure if I'd fit 2 or 3 nics into
it.
Typical NICs support only A, only B (if several years old),
or B/G if more recent. Some now also support N, if the
small cost difference is not important and considering the
purpose of the system I would pick one supporting B/G/N.

I'm pretty sure the couple of laptops I need to support are either B or G,
so that's fine. I want N for future-proofing and incase I go wireless with
the desktop.
Do you really need a separate computer for this? Check out
DD-WRT firmware for wifi routers and which ones it supports,
you might be able to do this cheaper, using less
power/space/noise, and have the P4 box available for some
other use.

Most definately. I want routing, firewall, traffic shaping, remote access
and likely one or two more extras.
What trouble? A router does not need a lot of memory and
modern PC CPU - it just isn't a job requiring a lot of
memory and processing performance. Sometimes slow
performance is really just poor signal quality, that the
environment requires an additional access point or
directional antennas if there's a lot of background noise
from distant sources.

I own a Belkin F5D7230-4. Google the model number if you want horror
stories - everybody has huge problems.

My problems/needs:

a) It overheats massively. I'm talking too hot to touch after just an hour
or two.
b) It stalls and crashes constantly. I have to reset or power cycle at least
every 30 minutes to do anything.
c) ANY P2P software kills the router almost instantly. As soon as someone
starts limewire the router freezes in minutes and the whole network goes
down.
d) There are no real firewall controls. Manually blocking 2 or 3 ports is
not a firewall (I want to be able to use FreeBSD's IPFW )
e) I'd like to do traffic shaping where I can limit how much bandwidth each
PC is using (I don't want a P2P app on one PC suck all 95% of the DSL
connection)

There's also the possibility of using it as a file server too. I'm familliar
with configuring a router - I've just never gone wireless before.

Chris
 
K

kony

Are we talking like shuttle size integrated board ? If I can get what I need
cheap then I'd definately go that way (so it fits on my desk). I wanted
something that size initially, but I wasn't sure if I'd fit 2 or 3 nics into
it.

Why do you need 2 or 3 nics? They tend to have at least one
slot and an integrated 100Mb (maybe newer models now have
1GB) ethernet adapter.


Most definately. I want routing, firewall, traffic shaping, remote access
and likely one or two more extras.


I own a Belkin F5D7230-4. Google the model number if you want horror
stories - everybody has huge problems.

Have you tried updating the firmware and improving cooling
with a 'sink on the network processor and more holes in the
casing? Hearing of problems doesn't necessarily tell us
what the cause was?

My problems/needs:

a) It overheats massively. I'm talking too hot to touch after just an hour
or two.
b) It stalls and crashes constantly. I have to reset or power cycle at least
every 30 minutes to do anything.
c) ANY P2P software kills the router almost instantly. As soon as someone
starts limewire the router freezes in minutes and the whole network goes
down.
d) There are no real firewall controls. Manually blocking 2 or 3 ports is
not a firewall (I want to be able to use FreeBSD's IPFW )
e) I'd like to do traffic shaping where I can limit how much bandwidth each
PC is using (I don't want a P2P app on one PC suck all 95% of the DSL
connection)

Don't P2P apps these days allow setting the bandwidth and #
of connections on the client system running it?


There's also the possibility of using it as a file server too. I'm familliar
with configuring a router - I've just never gone wireless before.

Wireless isn't much different, but to recognize some 'sites
won't be effectively covered by a single point and/or with a
stock antenna. Until you pick a nic and try it, it's hard
to speculate about any particular environment but the
location of the router might determine whether you'd want an
omni or directional antenna.
 
D

DevilsPGD

In message <[email protected]> "Skeleton Man"
Are we talking like shuttle size integrated board ? If I can get what I need
cheap then I'd definately go that way (so it fits on my desk). I wanted
something that size initially, but I wasn't sure if I'd fit 2 or 3 nics into
it.

There are some multiple-interface cards out there that are pretty
decent...
 
R

Rod

Skeleton said:
Hi guys,

I'm looking at building a wired/wireless router from a spare P4 box I have,
and I'm thinking wireless N is the way to go. I was wondering though if the
nics are backwards compatible with A/B/G ?

Also, I'm thinking a seperate antenna would be best as the router will sit
out of sight and not atop my desk, etc. Could I just buy a couple of
omni-directional antennas and attach to the NIC ?

Another option I considered was a combination of a wired router and a good
access point (like Minitar, etc) to provide the wirless capability.

One last thing, is there any real performance difference in having only 2
two antennas vs 3 antennas ? From what I read only the two with the best
signal are used anyway right ?
I would suggest a read of:-
http://www.arubanetworks.com/pdf/technology/whitepapers/wp_Designed_Speed_802.11n.pdf
You will find that MIMO antennas are spaced a identical fraction of
wavelengths apart and that they are pretty well matched to each other.
 
S

Skeleton Man

Why do you need 2 or 3 nics? They tend to have at least one
slot and an integrated 100Mb (maybe newer models now have
1GB) ethernet adapter.

Nic 1: DSL Model
Nic2: Wired LAN
Wireless Nic3: Wirlesss LAN
Have you tried updating the firmware and improving cooling
with a 'sink on the network processor and more holes in the
casing? Hearing of problems doesn't necessarily tell us
what the cause was?

Firmware is the latest available and has made zero difference. Haven't tried
a heatsink yet.
Don't P2P apps these days allow setting the bandwidth and #
of connections on the client system running it?

Yes but when you have 3 PCs and 2 - 4 laptops each with 3 or 4 different P2P
apps it's a pain to configure each one.
Wireless isn't much different, but to recognize some 'sites
won't be effectively covered by a single point and/or with a
stock antenna. Until you pick a nic and try it, it's hard
to speculate about any particular environment but the
location of the router might determine whether you'd want an
omni or directional antenna.

I was under the impression you used directional for linking AP's, etc (where
you have only two devices pointing right at each other) and omnis for tx/rx
with clients ?

Chris
 
K

kony

Firmware is the latest available and has made zero difference. Haven't tried
a heatsink yet.

It's worth a try, and putting the holes in the router
casing. I go ahead and do that immediately with any router
after confirming it wasn't DOA.


Yes but when you have 3 PCs and 2 - 4 laptops each with 3 or 4 different P2P
apps it's a pain to configure each one.

?? Can't be much more of a pain than using each one? Only
takes a few seconds to do it, and by doing it you keep
network traffic down by stopping the requests before they
get to the router. This is more important on b/g wifi than
ethernet.


I was under the impression you used directional for linking AP's, etc (where
you have only two devices pointing right at each other) and omnis for tx/rx
with clients ?

Not necessarily, depends on where the router is relative to
where the clients are, and just how "directional" the
directional antenna is. I'm not talking about something as
directional as a yagi but rather a typical flat panel type,
mounted at one end of the premises plus another mounted at
the other end will help to reject noise coming from outside
the premises.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top