Mailing List os2-wireless_users@2rosenthals.com Archived Message #6639

From: "Lewis G Rosenthal" <os2-wireless_users@2rosenthals.com> Full Headers
Undecoded message
Subject: Re: [OS2Wireless] Zyxel AG-225H and Mesh Questions
Date: Sun, 28 Feb 2010 15:15:55 -0500
To: OS/2 Wireless Users Mailing List <os2-wireless_users@2rosenthals.com>

Hi, Mike!

On 02/27/10 01:30 pm, Mike Luther thus wrote :
Hi Folks!   I have a Zyxel AG-225H USB Wireless Finder and USB adapter tool I have had for   some time now and used only to just visually scan things for the A, B and G   networks it can find.  As I understand, it can also be used as a transceiver for   actual connections too.  I've never tried that.  OK, I'd love to be able to do   that with OS/2, but as usual, the CD-ROM and so on is Windows mess.    Suggestions as to how this might be accomplished?  It is a nice unit and would   be very helpful for another project I'm about to tackle.  Or one that tackles me   (us).     
No clue whatsoever. Perhaps someone else may be of some help. I'm not familiar with this gizmo.
Second pathway here.  One of my RV oriented friends is very much involved with   Wi-Fi connections with two OS/2 MCP2 everything laptops.  Thinkpad's, an R51 and   T43p that we fully set up with a LinkSys 45G Router and LinkSys wireless   receiver.  Which then use 'normal' OS/2 LAN connections to the DHCP addresses   furnished by the 45G router.  I originally set all this up for here and she   originally was  using the Hugh's Satellite system with the big sliced parabolic   antenna, but the cost of that per month got out of hand.  So she (we) went to RV   park Wi-Fi which worked beautifully for a long time.      
Okay...
Well now, many of the parks are starting to use what they call Mesh technology.    And all the setup connections we worked out no longer work.  Can someone here   point me toward a learning process for Mesh for OS/2 use.  Not necessarily for   direct embedded connection to the ThinkPad's.  But with the hard wired tools   would be OK too.      
Mesh is a technology related *solely* to the AP's. On the client side, it should have no impact whatsoever.

Essentially, it is possible to distribute RF signal between AP's in a couple of different ways: WDS and mesh. WDS (Wireless Distribution System) is a non-standardized, though fairly common method for a group of AP's to allow roaming of clients between them (sharing the same SSID) and to extend signal without cabling the AP's together. I have a shopping center configured in this manner. The downside of WDS is typically that the units using this method each have a single radio, so the WDS traffic steals bandwidth which would otherwise be usable by the clients. Also, in a daisy-chain scenario:

   Ex. 1:

   AP-1 -)))) AP-2 -)))) AP-3

if the AP in the middle (AP-2) goes down for some reason, clients on AP-3 are out of luck, because there's no way for AP-3 to talk to AP-1 (which is likely connected to the broadband router), so a 33% communications failure takes down 67% of the network in a 3-node configuration. Attempting to add a second pathway from AP-1 to AP-3, even if the signal is string enough, leads to a whole host of routing loops, echo, and signal degradation (tried it once; never again). For that type of modification, you need mesh.

Mesh is a proprietary technology. That means that as mesh is not part of the 802.11 standard, each manufacturer employs its own flavor. Thus, a Tropos AP cannot participate in an Orinoco mesh or vice versa. For the manufacturers, this is a good deal, as by definition, "mesh" implies three or more units, and so a single manufacturer sews up triple the sales (at least) in one customer.

Mesh provides for a self-healing network. Assuming the same topology as Ex. 1, if AP-2 were to suddenly disappear (a unit mounted on a traffic signal pole, hit by a car and toppled over - yes, it happens...all the time!!), AP-3 will seek out an alternative route to AP-1, which is configured as the "gateway" device. If this means a direct connection to AP-1 (as there would be no AP-4, or AP-5 available or with a better signal quality), it will try it's d-mnedest to make that connection. It might have to fall back to 2Mbps, but it will try to hold on for dear life. What this means is that people who would otherwise have been without signal, at least have some connection. When AP-2 comes back online, AP-3 will automagically fall back to its "normal" behavior.

Now, as for what your problem is now that they have switched to mesh, I can't say. Start by trying to find the signal in the WRT54G. If th AP's have changed, but the outfit has retained the same IP addressing scheme, it is possible that you are in fact associated but that your arp table is out of date (i.e., you're trying to find a hardware address which is not longer assigned to the IP address you have in the table). Usually, a reboot will clear this up. Also, ensure that the LinkSys has a valid MAC address when requesting a DHCP address, as this can cause all sorts of issues (bald patches, broken glass, dogs and cats living together, etc.).

Without knowing more about the setup, I'm afraid I can't really give you better direction on how to troubleshoot. I hope this at least gives you some context and thus helps you suss out what's going on with the signal.

GL

--
Lewis
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Lewis G Rosenthal, CNA, CLP, CLE
Rosenthal & Rosenthal, LLC                www.2rosenthals.com
Need a managed Wi-Fi hotspot?                www.hautspot.com
visit my IT blog                www.2rosenthals.net/wordpress
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