October 21, 2008 General 0

I had a client that has two palm treos running windows mobile and activesync 4.0 and above.  When they would connect to their machines and sync via usb they would loose connection to their server.  I had a windows mobile PDA but never experienced this issue.  I just recently upgraded to a HTC Touch which runs windows mobile.  Sure enough when i had it sync my computer would go into offline mode and i would loose file/print connectivity to the network.  I did some digging and here’s what i found(I’ll keep the HIGHLY technical details out):

1. By default activesync creates a new network adapter based on the usb device.

2.  When you connect the device and sync the device goes though a ghost dhcp.  Once it gets it’s “address” it begins transferring data..for some reason many times this causes the computer to head into offline mode therefore killing windows file sharing connectivity.

3.  disconnecting the device DOES NOT restore the machine to online mode..you have to re-initialize online mode manually which leads to other issues.

Here’s how to fix it(at least on the touch..your pda may have this located in another spot):

start-settings-connections-usb to pc

uncheck “Enable Advanced Networking Functionality”

advantages?  Your networking stack doesn’t get screwed up and you don’t have to jump through hoops to continue to use your computer.  Your windows firewall won’t nuke the connection by default either.

disadvantages?  The transfer can be noticeably slower..BUT it’s still MUCH faster than a serial connection so you still get the benefits of USB tansfers.