DataSocket server hangs when remote client connects

[Shea24]

Hello,

I have a data socket server running on Computer A. I am publishing measurement data to Computer A from Computer A, which I can read successfully from other applications on A.

However, if I try to connect to *any* of the data sockets on Computer A from Computer B, the data socket server appears to "hang" for 10-15 while a connection is being established. Note that B can be any computer on the network that is not A (I've tried more than one computer). Once a connection is established, everything is fine. However since we will potentially have multiple clients connecting, and they can connect at any time, the "hang time" is not acceptable. A and B are connected via a 10 mbit connection without much traffic, so I don't believe it is a physical networking issue.

I've experienced this issue before at other client's sites, but it hasn't been a show stopper until now.

I believe this is the same issue described in this post:

http://forums.ni.com/ni/board/message?board.id=230&message.id=2615&query.id=58337#M2615

Any help would be greatly appreciated.

Regards,

Shea

[DWeiland]

Hi Shea,

When you are trying to connect Computer B to Computer A, do you see the "hang" only if Computer A is also trying to read from the DataSocket? Or regardless of clients on Computer A, do Computer B connections always hang?

You're posting in the .NET Languages forums so I assume that you are using the DataSocket assemblies and not the ActiveX MStudio 6 DataSocket controls. Is this correct?

Can you try connecting Computer A to Computer B with a cross over cable? I want to make sure that the network isn't a factor, and directly connecting the computers with a cross over should show us definitively whether or not the network is slowing things down.

Let us know Shea, thanks.

[Shea24]

Hi Dan,

Thanks for the response.

The "hang" occurs when I try to establish a connection to any datasocket on computer A from computer B, regardless of whether A is reading from the datasocket. (With the datasocket in question, it is a simple boolean value, the only consumption of which is from computer B - it is not being read at all by A, only populated).

You are correct in assuming I am using the DataSocket assemblies and not the ActiveX MStudio 6 Datasocket controls.

I am unfortunately unable to try using a crossover cable to connect the two (not on the clients site anymore - however I can VPN in and remotely control A and B). Note that I can ping B from A continuously (for many minutes) and never have a reponse > 10 ms. They are connected through a gigabit switch.

Regards,

Shea

[DWeiland]

Hi Shea,

Would you mind posting a small example that demonstrates the problem you're seeing? I'd like to test it out on our end and see if it's reproducible.

Also, does your customer's company have any firewalls to take into consideration?

Thanks Shea. Have a good one.