PDA

View Full Version : Low wireless throughput



Wicewolf
2007-11-25, 05:02
I really have a throughput problem. When my SB is connected to my WLAN network I only get a rate of about 200kbps. My setup is a laptop and the SB both connected to a wireless router.I have tried all available channels to exclude any interference issues from neighbours etc (Have only two neighbour wlan network), and even been standing about only 1 meter from my router with both laptop and SB to be sure to have a dominant signal. My laptop works all fine wireless and I have superb download speed on that and have no inteference problem. When I connect SB to my router by cable and my laptop still connected wireless it all works all fine with superb rate. I have tried my SB in my friends house with another router and there it worked all fine all wireless, so that should exlude that my SB is faulty.What could cause this? Could there be any wireless issues with my router? My router is a Zyxel ZyAir B-2000 v.2 with the latest firmware. I suspect it could be a router problem but I would not like to buy another before I wuite sure it's where the problem lies.
And if the problem lies with my wireless router, what alternative router with good coverage could be recommended?

servies
2007-11-25, 05:37
One cause could be that you're using 2 wireless paths...
laptop -> router and router -> SB3
That means that the 54Mb/s is already to be divided over 2 devices but 200kb/s is very low...

Mark Lanctot
2007-11-25, 08:29
One cause could be that you're using 2 wireless paths...
laptop -> router and router -> SB3

Definitely, the first thing that must be addressed.


That means that the 54Mb/s is already to be divided over 2 devices but 200kb/s is very low...

In reality you'll never get 54 Mbps, it's more like 20 Mbps. In my case it's about 13 Mbps.

Wicewolf
2007-11-25, 11:05
Definitely, the first thing that must be addressed.



In reality you'll never get 54 Mbps, it's more like 20 Mbps. In my case it's about 13 Mbps.

But that can't be the reason. Even though the bandwith is shared between both SB and laptop there should be plenty of resources to give much better performance than this. Besides I have tried both the SB and my laptop installed at my friends wlan and there was no problem at all.

jeffmeh
2007-11-25, 12:18
But that can't be the reason. Even though the bandwith is shared between both SB and laptop there should be plenty of resources to give much better performance than this. Besides I have tried both the SB and my laptop installed at my friends wlan and there was no problem at all.

Actually, the two wireless hops can definitely be the reason. While that can work for some, it leaves very little margin for any wireless problems. If you can wire one of them and get it to work, do so.

amcluesent
2007-11-25, 12:28
>I have tried both the SB and my laptop installed at my friends wlan and there was no problem at all<

Pretty much says your wi-fi access point/router isn't too clever OR your site is suffering a lot of interference on the wi-fi frequences.

Mark Lanctot
2007-11-25, 17:01
But that can't be the reason. Even though the bandwith is shared between both SB and laptop there should be plenty of resources to give much better performance than this.

Servers are really meant to be wired. Really.

If a wireless server works for you, great, but it's the exception, not the rule.

Also the resources are not shared like servies describes (bandwidth/2), it depends on walls, interference and router efficiency at redirecting packets. Receiving and re-transmitting packets can introduce significant latency which will impact bandwidth.


Besides I have tried both the SB and my laptop installed at my friends wlan and there was no problem at all.

Each wireless location is different and each router performs differently. Perhaps there were less obstacles at your friends place, perhaps there were less competing networks, perhaps there was less interference, perhaps his router is more efficient than yours. But the fact remains that it doesn't work for you and there's not much you can do beside wire the server or the SB.

bpa
2007-11-25, 17:19
You might consider buying a new router as AFAICT the Zyxel ZyAir B-2000 is a 802.11b only router - which canonly offer 11Mbs max.

pfarrell
2007-11-25, 17:48
bpa wrote:
> You might consider buying a new router as AFAICT the Zyxel ZyAir B-2000
> is a 802.11b only router - which can only offer 11Mbs max.

Just checked the Zyxel site and there is no mention of 11g on that model.

While 11b has a theoretical max of 11Mb, it rarely delivers that. With
two wifi hops, you have not much chance of it working reliably

So I agree with BPA, get a better router. I just bought a Linksys
WRT54GL which can be flashed with DD-WRT. It only costs $2 or so more
than the base WRT54G, which is too limited to run good firmware. I paid
$60 from newegg. the DD-WRT folks recommend a specific Broadcom router
as being the least expensive implementation of the basic good hardware.


--
Pat Farrell
http://www.pfarrell.com/

Wicewolf
2007-11-26, 12:59
What I don't understand is:
I'm having both laptop and SB in the same room as the router (only 1 meter ditance). No other wlan around to interfear on the channel I'm on.
Setup 1: Laptop is wireless and SB is wired: Everything is ok and the throuput is excellent
Setup 2: I switch; Laptop is wired and the SB is wireless. Througput is really bad (app 200-300 kbps)!!

As my router is only b-mode, I understand it has it's limitations, but nevertheless...this setup should give a much better performance and at least the performanced shouldn't be that different in these very similar setups?

Please help! :-)




Servers are really meant to be wired. Really.

If a wireless server works for you, great, but it's the exception, not the rule.

Also the resources are not shared like servies describes (bandwidth/2), it depends on walls, interference and router efficiency at redirecting packets. Receiving and re-transmitting packets can introduce significant latency which will impact bandwidth.



Each wireless location is different and each router performs differently. Perhaps there were less obstacles at your friends place, perhaps there were less competing networks, perhaps there was less interference, perhaps his router is more efficient than yours. But the fact remains that it doesn't work for you and there's not much you can do beside wire the server or the SB.

bpa
2007-11-26, 13:46
To be sure what is happening - you would need to analyse the network exchanges and probably wifi settings.

You said yourself that the SB works fine with a friends router so it looks like a SB-Zyxel Wifi networking (i.e. not TCP/IP) issue.

My guess is that it is a compatibility issue. Your router model is about 4 years old and it wasn't very long ago that Slimdevices had to publish a list of routers that work / do not work with an SB. I suspect a negotiated wifi parameter is restricting throughput with the SB but the PC is able to handle a better setting.

Wicewolf
2007-11-27, 13:42
Today I bought myself a new router; D-Link DIR-655. It was obviously the Zyxel ZyAir B-2000 router having some problems. With my new router it all works all fine. Thank you all for your help.