Two Netgear WGT624 models will not communicate

I have a pair of Netgear WGT624 routers. They have been configured
exactly the same, other than for static IP addresses. Either router
works fine to communicate with my wireless printer (HP 6980). So I
know things are basically working. The problem is, the two routers
do not seem to communicate with each other.

The intention of these routers is to establish fast LAN connectivity
with my brother's house right across the street. Distance is about
60 feet.

I've been doing the testing with both routers inside at distances that
vary from 3 to 12 feet. The printer is 30 feet away toward the other
side of the house, and the reported signal strength is 5 out of 1-5.
Ping timings with the printer is very good. ARP resolution shows the
printer MAC address, so it is a direct in-segment communication. And
this works for either router being used.

All the computers are in one room and connected with a wired switch.
The routers are plugged into the switch one or two at a time to be
configured and/or tested (and also when I need to do printing). I
can ping the router IP addresses as well as the printer IP address
just fine, but for the routers this is only when they are plugged in
the switch. When I have one of the routers not on the switch, then
it cannot be reeached.

Both routers are identical (except for MAC addresses):
Manufacturer: Netgear
Model: WGT524NA
Hardware: V3H1
Firmware: V2.0.10_1.0.1NA

Both routers are set as follows:
Channel: 08
Mode: g and b
Security: WPA2-PSK [AES]
SSID: (same including same as printer)
Passphrase: (same including same as printer)
RIP Direction: Both
RIP Version: RIP_2B

If I can reach the printer (ping works, printing works) when just one
of the routers is connected to the wired switch, why would I not be
able to reach the other router? Are they somehow designed to not
communicate with each other?

--
-----------------------------------------------------------------------------
| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
-----------------------------------------------------------------------------

On 19 Jul 2006 04:54:44 GMT, phil-news-(E-Mail Removed) wrote:

>I have a pair of Netgear WGT624 routers. They have been configured
>exactly the same, other than for static IP addresses. Either router
>works fine to communicate with my wireless printer (HP 6980). So I
>know things are basically working. The problem is, the two routers
>do not seem to communicate with each other. (...)

1. Yep:
- Wireless routers and access points do NOT talk to each others.
- Wireless bridges will talk to each other.
- Wireless routers with WDS (wireless distribution service) will
talk to each other.
- Wireless client adapters and wireless client bridge adapters
will talk to a wireless router or access point.

2. If you switch to wireless bridge, the wireless printer and other
wireless clients will NOT be able to talk to either bridge radio.
Therefore, this is a bad idea. I presume that you cannot run CAT
between the two wireless routers, so you're only useful option is WDS,
which will allow simultaneous bridging and acting as an access point.
You'll need to buy different boxes.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

On Wed, 19 Jul 2006 05:40:40 GMT Jeff Liebermann <(E-Mail Removed)> wrote:
| On 19 Jul 2006 04:54:44 GMT, phil-news-(E-Mail Removed) wrote:
|
|>I have a pair of Netgear WGT624 routers. They have been configured
|>exactly the same, other than for static IP addresses. Either router
|>works fine to communicate with my wireless printer (HP 6980). So I
|>know things are basically working. The problem is, the two routers
|>do not seem to communicate with each other. (...)
|
| 1. Yep:
| - Wireless routers and access points do NOT talk to each others.
| - Wireless bridges will talk to each other.
| - Wireless routers with WDS (wireless distribution service) will
| talk to each other.
| - Wireless client adapters and wireless client bridge adapters
| will talk to a wireless router or access point.
|
| 2. If you switch to wireless bridge, the wireless printer and other
| wireless clients will NOT be able to talk to either bridge radio.
| Therefore, this is a bad idea. I presume that you cannot run CAT
| between the two wireless routers, so you're only useful option is WDS,
| which will allow simultaneous bridging and acting as an access point.
| You'll need to buy different boxes.

Can a WDS talk to a router? If I can find one box that can talk to both
routers, that wouls still achieve my goal with the same number of boxes.

A wireless card in a PC is not option for this.

The goal is to connect LANs in 2 houses across the street from each other
about 55 feet apart.

Why the different technologies? Wouldn't it have been simpler to design
one universal protocol that worked everywhere much as ethernet is, and
then let thinks like routing be added on top of that?

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2006-07-19-(E-Mail Removed) |
|------------------------------------/-------------------------------------|

phil-news-(E-Mail Removed) wrote:
>The goal is to connect LANs in 2 houses across the street from each other
>about 55 feet apart.

Do you want either or both of the houses to also have WiFi available
to other computers?

phil-news-(E-Mail Removed) hath wroth:

>Can a WDS talk to a router?

No. WDS is a protocol used to make wireless routers talk to each
other.

>The goal is to connect LANs in 2 houses across the street from each other
>about 55 feet apart.

Thanks for disclosing what you're trying to accomplish. Since you
don't want anything inside the computah, and I'll guess that you have
more than one computah on both sides of the street, what you want is
an ordinary wireless router on the side with the
DSL/cable/satellite/whatever, and an ethernet client bridge radio on
the other side. The WGT624 will suffice for the router.
http://www.netgear.com/products/details/WGT624.php
However, selecting the ethernet client bridge is going to be a bit of
a challenge. It has to be able to bridge more than one MAC address
which eliminates a few wireless "game adapters". I don't see anything
on the Netgear site that might work. Linksys WAP54G in client mode
will work. Same with several other access points that happen to have
a client mode. My current favorite is the WRT54G v3 with DD-WRT
alternative firmware running in client mode.

If you only have one computer on the client side of the street, you
might consider a USB adapter or game adapter, which are MUCH simpler.

Also, even though it's only 55ft, make sure you have line of sight, no
trees in the way, and that the signal path isn't broken by passing
traffic.

In future questions, please include:
1. What problem are you trying to solve?
2. What do you have to work with?
It makes answering questions much easier.

>Why the different technologies? Wouldn't it have been simpler to design
>one universal protocol that worked everywhere much as ethernet is, and
>then let thinks like routing be added on top of that?

I'll spare you my opinions of standards committees and "universal"
solutions.

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

On Wed, 19 Jul 2006 06:42:08 -0400 William P.N. Smith <(E-Mail Removed)> wrote:

| phil-news-(E-Mail Removed) wrote:
|>The goal is to connect LANs in 2 houses across the street from each other
|>about 55 feet apart.
|
| Do you want either or both of the houses to also have WiFi available
| to other computers?

Let me give you full layout.

In my house (house one) I have a rack of computers in which it is not an
option to use a wireless PC card. The only option is something that can
connect via an ethernet port to the switch that services those computers.
I can make 1 or more of those computers act as a router as they are all
running *nix (no Windows there).

There will also be a DSL connection. It is not yet wired up, but it will
NOT go directly to the computer room. The intention is for DSL to go to
a wireless device such that if there is a lightning strike on the phone
line, only the wireless device connected to the DSL would be lost.

There is also a printer, which cannot fit in or near the computer room.
It is a wireless printer, model HP 6980.

I want the rack of computers to be able to talk to the DSL connection.
I want the rack of computers to be able to talk to the printer.

The printer and DSL do not need to talk to each other. However, if the
only way to make things work is to bounce packets off the DSL router, that
is acceptable.

In my brother's house is a cable connection. It already exists. There
are two computers at present, more later. The cable connects now to one
PC running Windows XP. His wife has a laptop with a wireless card that
can be used, which works when she takes the laptop to work. His son has
a computer that dual boots Windows 98 and Linux. He wants to add wireless
to get internet access from it, but he needs to have some parental control
on the access.

Both the Window XP machine, and his wife's laptop, need to access internet
(through their cable connection) and access my rack of computers. Also,
his wife may bring her laptop over here and need to access internet and
my computers ... but in this case, internet via my DSL will be fine. The
idea is that accessing things between houses NOT go by way of internet.

The houses are across the street from each other, about 55 feet. I don't
need full capacity between the houses, but I do plan to put a backup file
server over in my brother's house in the future, and sync the two together
over the wireless (not going through DSL or cable).

Cross sharing of either internet connectivity is NOT required. I can do
that with in-computer routing or proxy servers, if ever needed. But the
wireless devices do NOT need to do any of that themselves. That might
overly complicate things, anyway.

Summarizing the logical connections needed:

1. Rack of computers [house 1] <-> printer [house 1]
2. Rack of computers [house 1] <-> DSL router [house 1]
3. Rack of computers [house 1] <-> visiting laptop [when at house 1]
4. printer [house 1] <-> visiting laptop (NICE but NOT essential)
5. Rack of computers [house 1] <-> Windows XP [house 2]
6. Rack of computers [house 1] <-> laptop [when at house 2]
7. Rack of computers [house 1] <-> Win98/Linux [house 2]
8. Cable router [house 2] <-> Windows XP [house 2]
9. Cable router [house 2] <-> laptop [when at house 2]
10. Cable router [house 2] <-> Win98/Linux [house 2] (NOT essential)

Note that the laptop does need access to the rack of computers from both
houses, but which way it gets in does not really matter. If it takes a
long path across the street and back, that's acceptable.

And again, a wireless PC card is definitely not an option on the rack of
computers. That connectivity is via its ethernet switch (preferred), or
an ethernet port in one of the machines, only.

I now have the 2 Netgear WGT624's. If they can continue to be used, fine.
If I need to replace them with something else, fine ... but I would need
to get past all the marketing BS the manufactures and retails give and get
exact model numbers that will communicate with each other (including with
what can be connected as internet routers to DSL here and cable there).

I hope that gives the complete picture.

--
-----------------------------------------------------------------------------
| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
-----------------------------------------------------------------------------

On Wed, 19 Jul 2006 08:02:06 -0700 Jeff Liebermann <(E-Mail Removed)> wrote:

| phil-news-(E-Mail Removed) hath wroth:
|
|>Can a WDS talk to a router?
|
| No. WDS is a protocol used to make wireless routers talk to each
| other.

Could you tell me why it is they can't talk to each other in the first
place? The air is like one big bus. Of course there are issues with
respect to radio frequency use. But once the radio waves are back in
a packet of bits, why would they not be able to work? Is the issue
that some units TX on one freq and RX on another, and other units have
that reversed (e.g. to do full duplex)?


|>The goal is to connect LANs in 2 houses across the street from each other
|>about 55 feet apart.
|
| Thanks for disclosing what you're trying to accomplish. Since you
| don't want anything inside the computah, and I'll guess that you have
| more than one computah on both sides of the street, what you want is
| an ordinary wireless router on the side with the
| DSL/cable/satellite/whatever, and an ethernet client bridge radio on
| the other side. The WGT624 will suffice for the router.
| http://www.netgear.com/products/details/WGT624.php
| However, selecting the ethernet client bridge is going to be a bit of
| a challenge. It has to be able to bridge more than one MAC address
| which eliminates a few wireless "game adapters". I don't see anything
| on the Netgear site that might work. Linksys WAP54G in client mode
| will work. Same with several other access points that happen to have
| a client mode. My current favorite is the WRT54G v3 with DD-WRT
| alternative firmware running in client mode.

Just got off the phone with Netgear pre-sales tech. He says use WG602
to talk to WGT624. But I have my doubts. I don't know if it's my
American accent confusing him, or his Indian accent confusing me.


| If you only have one computer on the client side of the street, you
| might consider a USB adapter or game adapter, which are MUCH simpler.

I don't think "client side of the street" is meaningful, here. Think
of it as connecting one ethernet LAN to another ethernet LAN. If it
were wired CAT5, either a crossover cable would do it, or a regular
cable with one end in a "upstream" port (the ones with reversed RX/TX).


| Also, even though it's only 55ft, make sure you have line of sight, no
| trees in the way, and that the signal path isn't broken by passing
| traffic.

Cordless phones on 2.4 GHz work between OK (base in one, carry phone to
the other).


| In future questions, please include:
| 1. What problem are you trying to solve?
| 2. What do you have to work with?
| It makes answering questions much easier.

I can build up to that. In many cases a succinct question works. And
when it doesn't, more detail can be provided.


|>Why the different technologies? Wouldn't it have been simpler to design
|>one universal protocol that worked everywhere much as ethernet is, and
|>then let thinks like routing be added on top of that?
|
| I'll spare you my opinions of standards committees and "universal"
| solutions.

I must assume there are split frequencies involved and some boxes TX on one
of them and other boxes RX on that one and TX on the other.

But if it's a genuine single frequency ping pong, then the engineers who
designed the part on the bits/packets side of things seem to have some
really twisted idea of how to infrastructure things.

BTW, if ethernet twisted pair, e.g. with those RJ-45 jacks, had been designed
with RX always on one side and TX always on the other, then what we know today
as a crossover cable would work. But in such a case, we would only need that
one type of cable and that one type of port and everything would always just
work. But no, some brainless dweeb decided we have to have 2 different kinds
of ports (so we can use straight through cables between them) and then have
yet another kind of cable to deal with the mixups. So yeah, I know how the
people that design these things can really make a mess of things. Seems that
wireless is ethernet gone even worse.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2006-07-19-(E-Mail Removed) |
|------------------------------------/-------------------------------------|

phil-news-(E-Mail Removed) hath wroth:

>Could you tell me why it is they can't talk to each other in the first
>place?

Maybe. Wireless topology was originally designed to be a star.
Central access point and clients that only talk to the central acccess
point. Additional access points can be added, but only with an
ethernet backbone. When 802.11 was first inscribed, the possibility
of building an extensible network topology was discussed, but not
implimented. Even the now ubiquitous repeater is only vaguely
mentioned and is very poorly defined.

The limiting factor in having two access points talk to each other is
in the bridging protocol. For a star topology, with clients that only
connect to one access point, the client bridge table need only keep
track of one MAC address to hardware port mapping. It's also easy on
the access point end because the AP need only keep track of whether
the MAC address is on the ethernet LAN, or wireless LAN interfaces.

Were to access points to talk to each other, they would by necessity
need to bridge more than one MAC address. That means a bridging
protocol that tracks the interface location of all the wireless
clients. That's missing in the typical access point.

What WDS actually does is graft this missing transparent bridging
protocol onto the access point. Rather than impliment a spanning tree
algorithm, WDS uses a fixed route table that requires users to
inscribe the destination MAC address of the other WDS routers in the
system. This would be necessary anyway for security purposes.

Some detail on WDS and how it works:
http://www.proxim.com/support/techbulletins/TB-046.pdf

I know that this is a somewhat simplistic explanation but I'm late for
a free lunch.

>The air is like one big bus.

True, but all protocols are not alike. The freeways are also one big
bus. Pedestrians, bicycles, and motor vehicles can all traverse this
bus. However, there's some question as to whether they can talk to
each or even co-exist.

>Of course there are issues with
>respect to radio frequency use.

RF is only the media layer. 802.11 encapsulates ethernet and can run
on other media besides RF. For example, the infrared comm
specifiction is buried in 802.11a.

>But once the radio waves are back in
>a packet of bits, why would they not be able to work?

For the same reason that Mac bits and PC bits don't interoperate
directly. They need either a common protocol or a conversion
mechanism. Just because they look like bits, doesn't mean they can
converse.

>Is the issue
>that some units TX on one freq and RX on another, and other units have
>that reversed (e.g. to do full duplex)?

No. Everything in 802.11 wireless is half duplex. A box can transmit
or receive, one at a time. In a WDS systems, all radios are on the
same channel.

>Just got off the phone with Netgear pre-sales tech. He says use WG602
>to talk to WGT624. But I have my doubts. I don't know if it's my
>American accent confusing him, or his Indian accent confusing me.

The WG602 is an access point. The data sheet shows that it supports
"bridging", which is a bit like saying that an automobile supports
moving. It's too vague. I don't have time to RTFM, but if the WG602
has a client mode, where you inscribe the MAC address of the access
point you're connecting it to, then it *MIGHT* work. The problem is
that you need to bridge more than one MAC address due to the number of
computers involved.

A better choice might be to purchase a transparent bridge, which will
support multiple MAC addresses, but not allow any connections from
client radios. I haven't read your detailed description of your
setup, but if any of the laptops need to connect to these wireless
bridge radios individually, a transparent bridge will not work.

>I don't think "client side of the street" is meaningful, here. Think
>of it as connecting one ethernet LAN to another ethernet LAN. If it
>were wired CAT5, either a crossover cable would do it, or a regular
>cable with one end in a "upstream" port (the ones with reversed RX/TX).

Sorry. I didn't read your detailed description before I posted the
above reply. I was guessing a typical laptop and desktop on one side,
not a server farm. A transparent bridge seems to be appropriate.
Normally, I would recommend a pair of WAP54G wireless bridges, but the
last pair are hanging all the time in bridge mode. I'm still looking
for a suitable replacement.

>Cordless phones on 2.4 GHz work between OK (base in one, carry phone to
>the other).

Not good enough. My 2.4GHz cordless phone will go about 1000ft (line
of sight). My wireless won't do that without replacement antennas.
The faster you go (data rate), the higher the BER (bit error rate). In
order to keep the BER reasonable, the range gets shortened.

Do you have line of sight? Can the antennas see each other? Are you
going through any walls, trees, bushes, etc? Windows are usually ok.
Line of sight is the single biggest determining factor of reliability
and performance.

>I can build up to that. In many cases a succinct question works. And
>when it doesn't, more detail can be provided.

You've done quite well in the other posting. What's missing is the
line of sight issue and performance expectations. How fast is the
cable modem?

>I must assume there are split frequencies involved and some boxes TX on one
>of them and other boxes RX on that one and TX on the other.

Nope. Everything on one "frequency" or rather channel as 802.11
spread spectrum occupies about 22Mhz of spectrum.

>But if it's a genuine single frequency ping pong, then the engineers who
>designed the part on the bits/packets side of things seem to have some
>really twisted idea of how to infrastructure things.

Yep. I'll forward your criticism. IEEE 802.11 was initially
standardized about 10 years ago. Rub your magic crystal ball and try
to define the exact wireless technology requirements for the next 10
years. I know people that are doing just that and it's not easy. If
extensibility is all that was left out of 802.11a/b/g, then I think
the committee did an exemplary job.

In effect, what you're asking for is mesh networking technology, where
the network can be extended by replicating access points. That's
being done in 802.11s, but has quite a way to go.
http://en.wikipedia.org/wiki/IEEE_802.11s

>BTW, if ethernet twisted pair, e.g. with those RJ-45 jacks, had been designed
>with RX always on one side and TX always on the other, then what we know today
>as a crossover cable would work.

I worked with a committee to do exactly that but with RS-232 on RJ-45
and RJ-50 jacks. It fell apart because manufacturers thought they had
some proprietary advantage to creative wiring and didn't want to
change their existing wiring schemes. When EIA-568A and B were
contrived, it was to try and simultanously satisify the telco and
computah mobs. That's not an easy job when Ma Bell is on one side,
and the rest of the planet on the other. That's why there are two
standards where EIA-568B is a clone of the Bell 258A wiring standard.
http://en.wikipedia.org/wiki/EIA_568A
Incidentally, when I saw my first modular plug in the early 1960's, I
almost barfed in disgust. What a flimsy piece of cheap junk is all I
can say. Well, Darwinian "Survival of the Cheapest" is apparently
epidemic in the connector business.

>But in such a case, we would only need that
>one type of cable and that one type of port and everything would always just
>work. But no, some brainless dweeb decided we have to have 2 different kinds
>of ports (so we can use straight through cables between them) and then have
>yet another kind of cable to deal with the mixups. So yeah, I know how the
>people that design these things can really make a mess of things. Seems that
>wireless is ethernet gone even worse.

The reasons why such things are done are not always evident. Telco
POTS wiring uses the center pair for L1 and straddles them with
another L2 pair. The remaining two pairs are for data. The goal was
to come up with a combined data/voice connector scheme that would
involve the least amount of wiring changes to existing hardware. Since
there were millions of voice connections, but very few data
connections, voice won. Were this done today, it would be very
different, but if you roll back the clock to the days of the 3B2, the
choices were very different.


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

On Wed, 19 Jul 2006 11:30:47 -0700 Jeff Liebermann <(E-Mail Removed)> wrote:
| phil-news-(E-Mail Removed) hath wroth:
|
|>Could you tell me why it is they can't talk to each other in the first
|>place?
|
| Maybe. Wireless topology was originally designed to be a star.
| Central access point and clients that only talk to the central acccess
| point. Additional access points can be added, but only with an
| ethernet backbone. When 802.11 was first inscribed, the possibility
| of building an extensible network topology was discussed, but not
| implimented. Even the now ubiquitous repeater is only vaguely
| mentioned and is very poorly defined.
|
| The limiting factor in having two access points talk to each other is
| in the bridging protocol. For a star topology, with clients that only
| connect to one access point, the client bridge table need only keep
| track of one MAC address to hardware port mapping. It's also easy on
| the access point end because the AP need only keep track of whether
| the MAC address is on the ethernet LAN, or wireless LAN interfaces.
|
| Were to access points to talk to each other, they would by necessity
| need to bridge more than one MAC address. That means a bridging
| protocol that tracks the interface location of all the wireless
| clients. That's missing in the typical access point.

Or alternatively, translate to level 3 and re-announce as IP addresses
in a routing protocol like RIP. But none of this is new; wire switches
do this all the time.


| What WDS actually does is graft this missing transparent bridging
| protocol onto the access point. Rather than impliment a spanning tree
| algorithm, WDS uses a fixed route table that requires users to
| inscribe the destination MAC address of the other WDS routers in the
| system. This would be necessary anyway for security purposes.

Would not the encryption of the packets themselves be sufficient
security? Seems to me that once you get RF into a bit stream/packet
then you want to be sure it is authorized (security) before doing
any more with it (valid SSID, phrase, key, etc).


|>The air is like one big bus.
|
| True, but all protocols are not alike. The freeways are also one big
| bus. Pedestrians, bicycles, and motor vehicles can all traverse this
| bus. However, there's some question as to whether they can talk to
| each or even co-exist.

For ethernet over wireless it's not much different than ethernet over
a coaxial cable, besides the greater noise, more lossage, and hackers
tapping in. Operationally, it seems like it should be the same. But
if there are separate RX and TX frequencies, a few things could get
more complicated.


|>Of course there are issues with
|>respect to radio frequency use.
|
| RF is only the media layer. 802.11 encapsulates ethernet and can run
| on other media besides RF. For example, the infrared comm
| specifiction is buried in 802.11a.
|
|>But once the radio waves are back in
|>a packet of bits, why would they not be able to work?
|
| For the same reason that Mac bits and PC bits don't interoperate
| directly. They need either a common protocol or a conversion
| mechanism. Just because they look like bits, doesn't mean they can
| converse.

That's what we have ethernet, IP, TCP, etc, for. Of course if two
strange machines want to talk to each other in Gibberish 2.0 then
why not.


|>Is the issue
|>that some units TX on one freq and RX on another, and other units have
|>that reversed (e.g. to do full duplex)?
|
| No. Everything in 802.11 wireless is half duplex. A box can transmit
| or receive, one at a time. In a WDS systems, all radios are on the
| same channel.

Then I can't see the reason for separate client mode at the media layer
other than to force the star topology. IMHO, star topology should not
be used in many cases.


|>Just got off the phone with Netgear pre-sales tech. He says use WG602
|>to talk to WGT624. But I have my doubts. I don't know if it's my
|>American accent confusing him, or his Indian accent confusing me.
|
| The WG602 is an access point. The data sheet shows that it supports
| "bridging", which is a bit like saying that an automobile supports
| moving. It's too vague. I don't have time to RTFM, but if the WG602
| has a client mode, where you inscribe the MAC address of the access
| point you're connecting it to, then it *MIGHT* work. The problem is
| that you need to bridge more than one MAC address due to the number of
| computers involved.

A limit on MAC addresses is something I can get around. I'll just split
up in subnets and route from one of the Linux boxes. In fact I already
have quite a number of subnets overlayed onto these machines in various
combinations now. Depending on which IP I send to, it could go direct
or be routed by some machine, or a different machine, or multi-hop. I
have 169.254.0.0/16 as one big segment subnet, and chopped 172.16.0.0/12
into a lot of varying sizes of CIDR.

It looks like the WGPS606 might actually do this. It shows in one of
the diagrams as communicating with a WGR614 router.

http://netgear.com/pdf_docs/WGPS606_ds_r1_3.pdf


| A better choice might be to purchase a transparent bridge, which will
| support multiple MAC addresses, but not allow any connections from
| client radios. I haven't read your detailed description of your
| setup, but if any of the laptops need to connect to these wireless
| bridge radios individually, a transparent bridge will not work.

The wireless printer does. I think that will be a client need. Also,
my sister-in-law might need net access here when she brings her laptop
over (unless we can be sure it will communicate on its own back to her
house).

If the transparent bridge will talk wirelessly to the router (WGT624)
then the router serving as the internet gateway can serve clients, IFF
it can be told to _route_ (it has RIPv2 so there is hope) over to my
LAN of computers.

I have an old brand-less model-less wireless bridge of some sort that
I was never able to get working before, but I might try playing with
it to see if I can trick it into working here.


|>I don't think "client side of the street" is meaningful, here. Think
|>of it as connecting one ethernet LAN to another ethernet LAN. If it
|>were wired CAT5, either a crossover cable would do it, or a regular
|>cable with one end in a "upstream" port (the ones with reversed RX/TX).
|
| Sorry. I didn't read your detailed description before I posted the
| above reply. I was guessing a typical laptop and desktop on one side,
| not a server farm. A transparent bridge seems to be appropriate.
| Normally, I would recommend a pair of WAP54G wireless bridges, but the
| last pair are hanging all the time in bridge mode. I'm still looking
| for a suitable replacement.

And one end or the other needs to connect to a DSL modem.


|>Cordless phones on 2.4 GHz work between OK (base in one, carry phone to
|>the other).
|
| Not good enough. My 2.4GHz cordless phone will go about 1000ft (line
| of sight). My wireless won't do that without replacement antennas.
| The faster you go (data rate), the higher the BER (bit error rate). In
| order to keep the BER reasonable, the range gets shortened.
|
| Do you have line of sight? Can the antennas see each other? Are you
| going through any walls, trees, bushes, etc? Windows are usually ok.
| Line of sight is the single biggest determining factor of reliability
| and performance.

Where I will be placing the router that connects to the DSL mode, its
antenna can see the window where the wireless would be in the other house.
The other house is lower in elevation but its wireless will be on the
2nd floor. They have tiny 4 watt lights in each window and I can most
or all of them. A couple trees are along the path, but not completely
blocking things, even with leaves.


|>I can build up to that. In many cases a succinct question works. And
|>when it doesn't, more detail can be provided.
|
| You've done quite well in the other posting. What's missing is the
| line of sight issue and performance expectations. How fast is the
| cable modem?

I'm not trying to pass cable modem (over there) traffic back to here.
I'm getting DSL here soon. But the cable seems to be as fast as I
might expect over there.


|>I must assume there are split frequencies involved and some boxes TX on one
|>of them and other boxes RX on that one and TX on the other.
|
| Nope. Everything on one "frequency" or rather channel as 802.11
| spread spectrum occupies about 22Mhz of spectrum.

So for 2 boxes by themselves it would be equivalent to ping-pong.


|>But if it's a genuine single frequency ping pong, then the engineers who
|>designed the part on the bits/packets side of things seem to have some
|>really twisted idea of how to infrastructure things.
|
| Yep. I'll forward your criticism. IEEE 802.11 was initially
| standardized about 10 years ago. Rub your magic crystal ball and try
| to define the exact wireless technology requirements for the next 10
| years. I know people that are doing just that and it's not easy. If
| extensibility is all that was left out of 802.11a/b/g, then I think
| the committee did an exemplary job.
|
| In effect, what you're asking for is mesh networking technology, where
| the network can be extended by replicating access points. That's
| being done in 802.11s, but has quite a way to go.
| http://en.wikipedia.org/wiki/IEEE_802.11s

I'm really asking for RF to be a media not unlike any other ethernet
media, besides the added "physical" security needs and management.
Beyond that, things like topology should be an administrative issue
that can be handled by smarter implementations or smart enough people.
Products could come with a default that works best for most and MAYBE
support other things. But the _standard_ should not rule out anything.

I can get around the goofy RX/TX pairing design of ethernet twistedpair
by simply using a crossover cable. Radio just isn't so easy, so that's
where I think the designers need to think it through, better. If it's
a case of everything alternates between RX and TX on one frequency
(which is good for assymetric loading, as much of web usage and file
transfers are to sometimes quite an extreme), then the one frequency
design is right. But it really should accept _any_ security authenticated
packet that comes in and pass it to the bridging/switching/routing layer
which should not have standards imitations on flexibility.


|>BTW, if ethernet twisted pair, e.g. with those RJ-45 jacks, had been designed
|>with RX always on one side and TX always on the other, then what we know today
|>as a crossover cable would work.
|
| I worked with a committee to do exactly that but with RS-232 on RJ-45
| and RJ-50 jacks. It fell apart because manufacturers thought they had
| some proprietary advantage to creative wiring and didn't want to
| change their existing wiring schemes. When EIA-568A and B were
| contrived, it was to try and simultanously satisify the telco and
| computah mobs. That's not an easy job when Ma Bell is on one side,
| and the rest of the planet on the other. That's why there are two
| standards where EIA-568B is a clone of the Bell 258A wiring standard.
| http://en.wikipedia.org/wiki/EIA_568A
| Incidentally, when I saw my first modular plug in the early 1960's, I
| almost barfed in disgust. What a flimsy piece of cheap junk is all I
| can say. Well, Darwinian "Survival of the Cheapest" is apparently
| epidemic in the connector business.

Wait until you see them attaching wireless antennas with those :-)
Watch grown men cry!

OTOH, I've seen some terribly shoddy installs of coax and crimpable BNC
connectors just jammed on (fell apart faster than F connectors).

Done right, coax can get up to 2 GHz on BNC, 4 GHz on TNC, 10 GHz on N,
and 24 GHz on SMA. That's assuming good cable, too.

But at least the length of the impedance bumps in RJ-45 is not too long
at 100 MHz.

But the whole mess with twisted pair just annoys me. Going cheap is
one thing. But then trying to be compatible with the twisted pair cables
the telcos already use is another. We ended up having to have crossover
cables, anyway. We should have made that THE standard cable which would
mean every jack would TX on one side and RX on the other side universally.
But I guess someone didn't like simplicity.

Ever seen a GR-874 coaxial connector?


|>But in such a case, we would only need that
|>one type of cable and that one type of port and everything would always just
|>work. But no, some brainless dweeb decided we have to have 2 different kinds
|>of ports (so we can use straight through cables between them) and then have
|>yet another kind of cable to deal with the mixups. So yeah, I know how the
|>people that design these things can really make a mess of things. Seems that
|>wireless is ethernet gone even worse.
|
| The reasons why such things are done are not always evident. Telco
| POTS wiring uses the center pair for L1 and straddles them with
| another L2 pair. The remaining two pairs are for data. The goal was
| to come up with a combined data/voice connector scheme that would
| involve the least amount of wiring changes to existing hardware. Since
| there were millions of voice connections, but very few data
| connections, voice won. Were this done today, it would be very
| different, but if you roll back the clock to the days of the 3B2, the
| choices were very different.

If voice would have stayed with 4-5 and 3-6 and left 1-2 and 7-8 for
data, AND if the 4 wires for 1-2 and 7-8 were always wired as crossover,
AND all ethernet ports would TX on one side and RX on the other, then
it might be just too easy.

OTOH, I still think it remains silly to have billions of these cables
around with 8 wires in them that are half never used. Copper conspiracy?
OK, at least they are starting to use them for gigabit.

I could have had 12 twisted pairs plus a ground pin on a DB-25. With the
same crossing-over logic, even that could have been made to work well.
Even DB-9 would have worked well that way.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2006-07-19-(E-Mail Removed) |
|------------------------------------/-------------------------------------|

On 19 Jul 2006 19:55:11 GMT, phil-news-(E-Mail Removed) wrote:

>| Were to access points to talk to each other, they would by necessity
>| need to bridge more than one MAC address. That means a bridging
>| protocol that tracks the interface location of all the wireless
>| clients. That's missing in the typical access point.

>Or alternatively, translate to level 3 and re-announce as IP addresses
>in a routing protocol like RIP. But none of this is new; wire switches
>do this all the time.

Ok, you lost me. Translate what to the IP layer? What will that do
to provide universal interoperability?

RIP on layer 3 is very similar to STP on layer 2. However, that would
dramatically increase the leve of complexity of wireless. By leaving
everything (except management and configuration) on layer 2, wireless
bridges avoid the complications of the IP stack.

>Would not the encryption of the packets themselves be sufficient
>security?

Maybe. Dunno for sure. Security in a WDS network is marginal. The
first problem is that many routers ran out of sufficient flash ram to
impliment both WPA encryption and WDS at the same time. The result is
that these are now mutually exclusive and only WEP is supported in WDS
mode. This has been fixed on some routers. I don't have the list of
winners and losers. I don't consider WEP to be adequate security.

Incidentally, the WAP54G wireless bridge has a similar problem. Bridge
mode and WPA are mutually exclusive. Grrr....

Even with WAP and WDS, there's a problem. There's only one WPA key
for the entire system. Everything, including the clients, have to
know this key. There are some routers that have multiple SSID's and
encryption methods/keys, but not in WDS mode.

As I see it (probably wrong), the MAC address in the configuration is
used to create the MAC to port mapping table (whatever it's called)
and to add an additional layer of security by doing some light weight
MAC address wireless filtering. Only those MAC addresses listed in
the WDS config page can "join" the WDS network. See:
http://www.linksysinfo.org/portal/fo...ad.php?t=47118
for a WRT54G sample configs. Oops. WEP again.

>Seems to me that once you get RF into a bit stream/packet
>then you want to be sure it is authorized (security) before doing
>any more with it (valid SSID, phrase, key, etc).

It sure would be nice to have WDS authenticate with 802.1x using a
RADIUS server. That would give each connection a temporary and unique
encryption key with a secure method of key exchange. Not this week.

However, I agree. If you consider WEP to be adequate security, then
it's probably also adequate for WDS.

>For ethernet over wireless it's not much different than ethernet over
>a coaxial cable, besides the greater noise, more lossage, and hackers
>tapping in.

Nope. 802.11 encapsulates 802.3 ethernet packets. Coax cable
(whether DOCSIS RF or 10base2 baseband) is simply layer 1 of the ISO
pile. The problem is that wireless tends to have more dropouts, more
lost packets, more noise, lousier signal to noise, and other anomalies
as compared to wired networks. The effects are the same with both
media, but the degree of imparement is much worse with wireless. I
can produce some S/N ratio comparisons for wired protocols versus
wireless protocols if you really need them. (Say no, I'm busy).

>Operationally, it seems like it should be the same. But
>if there are separate RX and TX frequencies, a few things could get
>more complicated.

Actually, they get simpler with full duplex. Flow control would
actually work. There would be no dead zones in the sliding window.
Repeaters could be built that don't cut the thruput in half. Etc.

>That's what we have ethernet, IP, TCP, etc, for. Of course if two
>strange machines want to talk to each other in Gibberish 2.0 then
>why not.

Wired TCP error control has no mechanism for dealing with repetative
errors. The best it can do is a random backoff algorithm to vary the
retransmission time to hopefully avoid the repetative interference.
802.11 wireless has multiple mechanisms, including flow control and
fragmentation control, to deal with interference issues.

>| No. Everything in 802.11 wireless is half duplex. A box can transmit
>| or receive, one at a time. In a WDS systems, all radios are on the
>| same channel.
>
>Then I can't see the reason for separate client mode at the media layer
>other than to force the star topology. IMHO, star topology should not
>be used in many cases.

This is not a la carte networking. You don't chose your topology,
protocols, and media from a menu as you need them. You get the whole
mess packaged as Wi-Fi, blessed by the Wi-Fi Alliance, and certified
by the FCC. There are plenty of places where a different topology
would be more useful. Too bad they're a minor consideration compared
to the huge number of situations where a star will work just fine. If
you want creative toplogies, look into Zigbee and mesh networking.

>A limit on MAC addresses is something I can get around.

It's a table size limit. Bottom of the line router manufacturers are
cheap. For example, Linksys was doing just fine with a WRT54G v3 that
had 16MBytes of RAM and 4MBytes of flash. However, they're latest
incantation has only half the RAM and flash. Never mind that it barfs
when faced with a large number of simultaneous streams, apparently
from running out of table space. Unless you can control the memory
allocation, you're not going to increase the MAC address count much.

Incidentally, some manufacturers seem to think that the way to
stratify the pricing for their bridges is by number of MAC addresses
passed. A "workgroup bridge" will typically do 4-16 MAC addresses.
The same model as a "transparent bridge" can do perhaps 2048.

>I'll just split
>up in subnets and route from one of the Linux boxes.

Sure. No problem. Sorry, I forgot to mention that. You only need
one MAC address passed to do routing. Put a router at both ends and
it should work.

(more later.... I gotta get back to work).

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS