Hello... So this is a last ditch attempt at getting an answer for my customer. This already went all the way up to Microsoft and since WM5 is no longer supported, I can't get an answer, although extensive work has been done concerning it... So they have about 14,000 MC70 devices with WM5. They use these for 2 or 3 different applications, some of the applications use connection manager, others don't. The devices connect via gprs and over wi-fi. They have a limited data plan and after changing their applications to use more real time information, their data useage went up almost 300%, however their calculations show it should be within their data limits. Turns out there is a bunch of overhead with IPv6. Had a GREAT fellow help me find all these settings to turn this off as well as get rid of additional overhead, so 5.5 out of 6 issues are resolved... On the application that uses connection manager, the device connects to GPRS and functions fine, however the device won't get an IP address or connect to their Wi-Fi network. Anybody have any idea why? This is the question my customer would like to know. Just wondering if anyone else ever ran up against this or heard or seen this before I put this completely to bed... Thanks for any information... Jesse
Connection Manager vs No Connection Manger in Windows Mobile 5// Expert user has replied. |
4 Replies
I think the problem (to do with not getting an IP) is down to how the terminal is configured. Can you confirm that Fusion IS able to connect to the WiFi. Then there is the question about the terminals not using the Microsoft provided Connection Manager. Are you sure that they are not using it automatically by default (as would be the case if they use IE or http/https connections)? If they are using urls in any way then the format of those urls (server/file or www.a.com/file) will cause Connection Manager to operate differently (Work or The Internet). GPRS is always in The Internet, WiFi can be either Work or The Internet. As Glenn observed the OS will hang on to any connection for as long as possible provided traffic is going across it. GPRS will time out after 10 mins or so of inactivity and then the built in functionality of Connection Manager will use WiFi (or Cradle) first before trying to reconnect to GPRS.
Mike, Tough one to provide a clear answer. It appears to be somewhat binary in behavior, On/Off. From a developer's perspective it pays to delve into understanding the behavior as best as possible and applying the controls as desired. To avoid the development nightmare look into one of the popular VPN clients for WM as some provide a level of control over arbitration of the connection. The user can determine under what conditions which network is selected. Sort of a poor man's "least cost route" measure!! Here is an MSDN article that provides some further insight into Connection: http://msdn.microsoft.com/en-us/magazine/dd263096.aspx
MS will maintain a connection as long as it can. Thus if the cellular connection was made last at the device still sees this connection it will use it. For the device to release the cellular connection it will need to lose this connection. How do you do this? Disable the card or go out of range. Once a connection is lost MS will test hardwired, wifi, cellular for a connection. Once it finds one it will stick with it until it is gone.
Hope this helps.
Glenn, do you happen to know if Connection Manager tracks any type of signal strength metrics? Or is the connection choice strictly based on an yes/no type of connection decision? I didn't see anything in the Connection Manger APIs (http://msdn.microsoft.com/en-US/library/aa457273), but thought I'd double-check... It would be nice if there was a way to switch to WiFi even when already connected via WWAN. Maybe a helper app (or something like SymScript) could be used to monitor WiFi and then help encourage the best connection choice...?