we have problems with applications (delay) trough ACCESS POINTS

[ROGER FERNANDO MAJO ZACARIAS]

Hello,

We are having many problems to connecte remore users to central site through a wireless link using access-points.

What is the problem:

1. when we connect the PC at the central site in the same switch where is connected the server and the user execute the application it responde very fast.
2. The program installed in the PC is VISUAL FOX PRO and in the server we have SQL.
3. When the pc is carried to a remote site and we use access-point to connect the central site to remote site, the application delay more than 5 minutes to get in session with the server.

Can someone tell us why the application delays so much to get in session with the server when we use access-point?

What we have observed using a ping plotter is that when the application is excuted there is a very big delay that reach 3000 msec during the execution process.

What changes we need to do to reduce this latency?

Maybe this application does not work through wireless link?

The access-point are from LINKSYS.

Waiting your answer.

Best regards.

[Leo Laohoo]

And if you plug the same client to the wire do you get the same response?

[ROGER FERNANDO MAJO ZACARIAS]

Hi.

We have carried the same PC to the central site and connected it to the wire segement and the response is very fast.

Only when we connect the PC to central site through a wireless link the delays increase to 3000 msec when try to connect to the central site.

Really, i do not what is happennig: the wireless link is setted to 25 Mbps (fixed) to avoid speed negotiation.

When the user use the same wireless link to access internet the response time is very fast. The delay only occur when it tries to get in session to SQL DATABASE at the cengtral site,.

The wireless equipment is from DLINK.

Any suggestion, please.

Attentively.

Roger Majo

[Nicolas Darchis]

Hi Roger,

You seem to say you tested only at the central site with a cabled computer. Did you try to connect via cable the application at the remote site ? We want to remove the internet factor in the delay you are seeing.

If the wired test on remote site is conclusive, then the next test is testing another application.

Can you try on the remote site an ftp transfer between a wireless laptop and a wired computer that is also on remote site for example ? This rules out the application or the wireless as the problematic factor.

Regards,

Nicolas

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[ROGER FERNANDO MAJO ZACARIAS]

Nicolas.

Thanks for your answer.

We are going to make the test suggested.

At the central site we are going install an access-point and with a wireless laptop and the replicate the same test.

Let two days to give you an answer.

Attn.

Roger

[ROGER FERNANDO MAJO ZACARIAS]

Leolaohoo,

We carried the PC from the remote site to the central site.

We connected the PC to the internal network (switch cisco 3560).

Then we execute the application and the operation is very fast. There is any delay.

With this test we conclude that the problem is in the wireless link (DLINK).

We have installed this wireless link about 15 days and our customer is claimed to replace the wireless but I need a solid base to replaced them.

What happen if we replace the wireless equipment with other manufacturer like: CISCO and so on the problem persist or happen again?.

Waiting your sooner answer.

Attn.

Roger Majo

[CSCO11167812]

Hi Roger,

Important things to know is the distance between the two buildings, obstacles and other possible interference.

Here is a link about antennas from Cisco

http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/product_data_sheet09186a008008883b.html

It could be that you are using access points which are not capable for the yob.

HtH

Michel

[Leo Laohoo]

The program installed in the PC is VISUAL FOX PRO and in the server we have SQL.

And the problem is only Visual Fox Pro and nothing else?  Any other application running on wireless is fine (on the same client)?

[ROGER FERNANDO MAJO ZACARIAS]

Hello Leolaohoo.

others programs works fine without any delay (internet, correo, etc),

Only when the user execute the VISUAL FOX PRO Application the delay increase about 3000 msec blocking all other application.

Then, every time the user request information from the local server the delay increase.

We have captured tha traffic with wireshark in this situations:

1. when the PC was carried to the central site and connected directly to the same segment of server (delay minimun)
2. when the PC is in the remote site (through wireless link) and the delay increase very high.

I am sending one file by one due they are heavy.

I f you can analize this files and determine what is the problem?

Thanks,