Wireless N top speed ; 130 Mbits/sec is my max, is this normal ?

[dominic.bilodeau]

Hi,

I've installed a WLC 5508 with 4 Ggps LAC trunk to a 3750 gig switch.  I have the 1142N-K9 access point plugged in Gig also.

I'm using all the best practice for a good Wireless N network (http://www.cisco.com/en/US/products/ps6366/products_tech_note09186a0080a3443f.shtml ).

My windows servers are 1 Gig as well.

When I use my brand new Lenovo laptop, with a full signal 300Mbit/sec wireless N, the maximum speed I get is around 120Mbtis/sec to any of our windows servers.

If I put the same laptop in place of the access-point, that is, unplug the access point from the 3750 gig port and plug my laptop, I can easily reach 400 Mits/sec.

I’ve tried a lot of things, other laptop, channel bonding in 5 mhz spectrum etc, that’s the maximum I could get (120 Mbits/sec).

So my question is, what’s you wireless N top speed ?

Thanks.

Dominic

[Surendra BG]

Hi,

N comes with 2 flavours.. N running over G radio and N Running over A radio.. If we are running N over G radio.. then the maximum speed that we get is 144Mbps and if we use N over A, then its 300  Mbps..

Regards

Surendra

[Peter Nugent]

Is channel bonding configured on the controller/access point in the tGHz range if not the best is 144Mbps.

[tcording]

Hi Dominic

I am presuming when you say 300mbps you mean that the client is showing that it is connected at 300mbps and the the 120mbps is tested throughput?

As 802.11 wireless is half duplex you will not be able to get a throughput 300mbps.

Normally you should be able to 144 - 200mbps depending on several factors, these include

• Distance to AP
• The clients wireless card configuration (the 802.11 hardware and software configuration)
• The configuration of the AP for 'N'. is it configured for a green field deployment of hybrid/migration deployment
• Other wireless noise forcing the packets to be resent
• Direction of traffic flow, are you testing throughput from the AP-to-client or Client-to-AP, the client hardware can greatly affect this

Troy

[Scott Fella]

Just to add to this... you did notice that your wired throughput on a gigabit connection is 400mbps so you are roughly only getting 40% throughput and is what you can use for your baseline.  Wireless as they mentioned is half duplex so you should see only hald at most when testing.  Seeing 120mbps seems okay from looking at the wired baseline you are showing.  Also you must be testing close to an access point since you are seeing 300mbps connection.