Long Socket Connnection Setup Time on 1Gb with Wireless NIC enabled but disconnected

[Pete_B]

We are encountering a performance issue on multiple laptops with socket connection times on a multi-homed Win-XP SP-3 system. This problem occurs when we have a 1 GB NIC enabled/connected and the wireless NIC enabled but NOT connected.

Many folks in the field run this way so when they remove their laptop from a docking station they can automatically connect via wireless without having to remember to manually enable or disable NICs. Hence disabling the Wireless NIC is a workaround but NOT a final solution based upon user feedback.

Test Application Overview

Our test app on the Win-XP server sits in a loop waiting for connection request from Clients.
Our test app running on the client does a query performance timing around the socket connect call. No actual data is passed…

Since we are just interested in measuring socket connection setup time the test app simply binds to the 1Gb NIC and makes a socket connection then closes the connection… BTW - once we are connected the data travels very quickly…

We have used the above test application / methodology to highlight the performance differences:
o Socket connection time is FAST (sub ms) on the 1GB NIC with the Wireless NIC disabled (effectively single homed)
o Socket connection time is Slow (~3.n seconds) on the 1GB NIC with the Wireless NIC enabled but not connected.

Route Print Metrics

Upon inspection of Route Print output with the 1GB NIC connected and the Wireless NIC enabled but NOT connected, it appears that Windows still puts one entry in the routing table for the wireless NIC into with a Metric of 1.

Has anyone else encountered this?

Is there a way to program around this?

Assistance appreciated…

Pete_B

[TheCPUWizard]

It is inherent becuase the system WILL try to route through the Wireless.

The "best" solution I have found is to install a simple service application that will automatically disable the Wireless, IF the Hardwwired has an IP (easist way in a DHCP environ to detect connection).

This can quitely run in the background and be installed on all the users laptops.

[Pete_B]

Thanks for the reply.

Based upon review of the Print Route output it is our understanding that the extra routing table entry when the wireless NIC is enabled but disconnected should only affect broadcast traffic, not TCP point-to-point socket connections…

I have a screen shot JPG of this however I can not attach it here.

Pete_B

[TheCPUWizard]

There are "forces at work" that operate below the level of the routine table and other visible artifacts. Trust me (I have been trough this many times) an enabled but non-conntected Wireless Connection WILL cause performance issues under various conditions. MUCH simpler to turn it on/off (automatically)