[MLB-WIRELESS] Re: [mesh] Transfer Rates

[Peter Board]

I did a bit more testing the other night.

On my local Windows Access point, I can get up to 260 kilobytes/sec transfer rate from my laptop with a wireless card through the AP to the wireless card that acts as a client on the linux router. Client -> AP -> Client - 260Kbytes/sec. Both of the client cards were in range of each other. 

My thoughts are that because I didn't have the hidden node problem, both clients could hear each other, the transfer rate was higher. The other links to this local Access Point which are 400m links (two of them) only achieve around 75kilobytes/sec. They both have LOS. They have to route their traffic through the Wireless Card on the linux router (as previously mentioned), but in theory they should be able to do the 260 KB/sec I can with my laptop.

Any idea's on how to speed the transfer rates up?

Just thought I would share my findings.

Cheers,

Peter
  ----- Original Message ----- 
  From: Peter Board 
  To: mesh at itee.uq.edu.au ; melbwireless at wireless.org.au ; Cameron Donaghey 
  Sent: Tuesday, September 17, 2002 4:44 PM
  Subject: Re: [mesh] Transfer Rates


  Hi Guy's,

  Over on our Digicate Nodes in the Beenleigh area, this is the sort of performance I have found (I am trying to up the performance but I believe I might need to fiddle with RTS/CTS values or possibly look at some driver changes. Hidden Nodes seem to be a major factor in performance problems. There are some special windows drivers that use a Turbo Cell custom mode that only works with Karnet Access Points that are supposed to optimise the network bandwidth via some polling arrangement).

  Firstly, we find if someone is doing a major file transfer, they knock out the weaker nodes (mainly our 7.5km Client node) under the large file transfer is done. We are using an Apple Airport (Lucent Silver card 8.10 firmware) as our main AP, all other cards are Cabletron Roamabouts running 6.06 to 8.10 firmwares.

  Transfer speed

  Wired client > Client Node (linux router) > AP > Wired Client (hanging off the access poing) ~ 450 to 500 Kb/sec

  Client Node > AP > Client Node, between 75Kb to 100 Kb/sec
  Client Node (linux router) > AP > Client Node (7.5 Km link) ~ 50Kb /sec
  Client Node (7.5 Km) > AP > wired client ~ 150Kb/sec

  We also have a second access point running under Windows (with driver hacks) but it does not seem to allow the traffic to pass to the Windows PC to be routed over Ethernet. Thus we use a second Wireless Card to route traffic via this Windows Access Point. Performance seems to be between 75Kb/sec and 120 Kb/sec. If the Windows drivers can be modified to allow local routing of the traffic over its ethernet interface, then I assume we should be able to get close to 450 - 500 Kb/sec (Client -> Ap -> wired)

  Anyone know what all the values are for the lucent drivers in the registry? Anyone got a Linux AP driver for Lucent / Cabletron cards?

  Peter
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