That is possible. > This is a multi-part message in MIME format. > > > MessageTom, > > Sorry, now turned off. > > Hmmm... since I am using switches not routers (and cheapo switches at that!) > I wonder if that might have something to do with it? Could be the packets > arrive at the switch and for whatever reason, it takes a while to work out > what to do with them. Sound plausible? If it is that, I wonder if > replacing the switch with a hub would make any difference? > > Peter > > > > Loop Scorpio Ltd > providers of Ledbury Broadband and Highnam Broadband > www.ledburybroadband.co.uk > www.highnambroadband.co.uk > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Tom Haynes > Sent: 16 July 2003 10:25 > To: [EMAIL PROTECTED] > Subject: RE: [smartBridges] Bandwidth Throughput > > > Peter, please turn off your 'Read recipt requested' for your emails to the > list. > > I had a similar loss per hop when I first started. It ended up being the > routers I used. I used a few linksys BEFSR41 4 port cable/dsl routers at two > towers. They worked fine in gateway mode, however I had a 200Kb drop in > throughput at each tower. After changing them to router mode and adding a > few static routes, I no longer have any lag even after 3 hops. > > > > internet--router--AP- - - - - -AP---router---AP- - - - - -AP--- router---AP- > - - - - -Client > > One other thing that gets a few people, double check your 'basic rates' > and 'auto fall back' from a computer connected to the device instead of over > the network. There has been problems reported in the past when someone > changed the setting remotely (From Chris I think. Right?). Everything looked > right from the NOC using simpleNMS but it was found that the clients > computer using simpleMonitor showed it still set at 1MB. If all else fails, > set the radios to a fixed 1 or 2MB with no fall back. Also make sure that > the AP (the one acting as an AP) is set to recieve all rates (check mark in > all boxes). > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Peter Cartwright > Sent: Wednesday, July 16, 2003 3:45 AM > To: [EMAIL PROTECTED] > Subject: RE: [smartBridges] Bandwidth Throughput > > > Tom, > > Thanks for the feedback. > > Default gateway ok, primary ports ok, all units on same subnet, APt's both > at least 12' above ground, all units mounted on poles... > > To be honest, I don't think it's a ping thing since the pings I get are > very good between the units (generally 1 to 2mS per hop). > > Also, no sign of errors etc in the SB monitor stats. > > The info I posted was the closest we have got yet to a structured test, > though we have seen similar things in another area where we have units > (small urban town) where the distances tend to be a few hundred metres using > roof top aerials. The effect seems constant across a variety of > installations which is what has me puzzled. Prior to taking up with SB we > used DLink 900AP+ units at both ends and had noticed similar effects. > > I find it all quite worrying since I had expected our bottleneck to be our > 2Mbps backhaul pipe and not the 11Mbps 802.11b network! > > Since we are in blighty, we tend to mount our aerials a few feet above > roof height and not on towers (would be next to impossible to get permission > and even if we did the money we would need to pay landowners etc would > destroy the business model). > > Putting science to one side, it "feels" like there is something happening > when the packets hit the 802.11b interfaces such that throughput decreases > significantly at each hop. I had wondered if it might be hidden node > effects, but switching on RTS/CTS (default is off) has not seemed to make > any difference. > > Peter > > > > Loop Scorpio Ltd > providers of Ledbury Broadband and Highnam Broadband > www.ledburybroadband.co.uk > www.highnambroadband.co.uk > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Tom Haynes > Sent: 16 July 2003 05:36 > To: [EMAIL PROTECTED] > Subject: RE: [smartBridges] Bandwidth Throughput > > > Make sure that the default gateway correctly in both units (closest > router to AP). Primary port on AP should be ethernet, on APcb should be > wireless. Make sure you are using IP numbers to test with (eliminates DNS > and NB delays). Make sure your souer is configured properly. make sure all > units are on the same subnet. Use trace route or VisualPingPlot to identify > where the lag is taking place. Make sure you "open field" has no > interference or large metal objects. Keep your APt's at least 6' above > ground to reduce ground interference. Make sure the units are mounted on a > pole instead of sitting on a table. It's all in the settings, read up on > what each one does and you should be able to get it to work. Good luck! > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Peter Cartwright > Sent: Tuesday, July 15, 2003 8:20 AM > To: [EMAIL PROTECTED] > Subject: [smartBridges] Bandwidth Throughput > > > {this is my first try on this email-forum, so I hope it works!} > > What sort of throughput do you all get with the Smartbridges kit? We > have been noticing some strange results and have been trying to pin down > what is happening. > > Closest we have got to a real test is as follows: > > Internet connection: 2Mbps > :: > ::=== computer (1) (connected via an Ethernet switch) > :: > AirpointProTotal (set as access point) > :: > 600m across basically a level open field (good RSSI and Link Quality) > :: > AirpointProTotal (set as client bridge) > :: > computer (2) > > We first ran a throughput test just over the link using QCheck. This > gave us around 1.2Mbps to 1.4Mbps from computer (1) to computer (2), but > strangely over 4Mbps the other way. > > Next test was using toast (www.toast.net/performance) to measure > throughput onto the Internet proper. Computer (1) would get around 1.2Mbps, > but computer (2) could only manage 0.6Mbps. > > In both tests, we would run first one computer then the other etc to > ensure that the same general conditions were applying. > > This seeems strange to us for two reasons: > > (1) why should the radio link throughput be so different in the > different directions? > > (2) why should the Internet throughput half when a single Smartbridges > link is added (which according to the first test is able to deliver > throughputs of well over 1Mbps). > > When we add in double/triple hops, the Internet throughput drops even > further. For example, adding an AirpointPro Outdoor - Airbridge Indoor link > as a second hop reduced the toast test to only 350Kbps. To me, this > suggests that it is 802.11b that is doing something. > > Anyone noticed anything similar, or have any ideas? > > Peter > > > > Loop Scorpio Ltd > providers of Ledbury Broadband and Highnam Broadband > www.ledburybroadband.co.uk > www.highnambroadband.co.uk > >
Laurence Laforga TIRGON Communications, LLC. dba Waipahu.Net Wireless Broadband The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://archives.part-15.org
