Hi

I've got a device with both GPRS and WLAN. I want my app to use the the
WLAN preferably, and GPRS if a WLAN connection is unavailable.

Looking for tips on how to best solve this problem. Only my app is to
contact the "world" via TCP/IP (webservices/whatever).

Is there a trick to checking what connection(s) are avaliable?

Is there a way to override the default gateway according to what is
avaliable?

What needs/can be programmed manually, and what can be configures within
Windows CE?

Thanks,
Finn Johnsen

If you want to know if you're connected to WLAN you can just simply hit some
known web host in your LAN and see if you get a response. For
programmatically connecting with GPRS you'd need to use RAS or ConnManager
API's.

For a free ConnManager implementation you can use SDF:

www.opennetcf.org/sdf

For a not so free, but full solution you can use:

http://www.intelliprog.com/netcf/ras.html

--
Alex Yakhnin, .NET CF MVP

"Finn J Johnsen" wrote:

> Hi
>
> I've got a device with both GPRS and WLAN. I want my app to use the the
> WLAN preferably, and GPRS if a WLAN connection is unavailable.
>
> Looking for tips on how to best solve this problem. Only my app is to
> contact the "world" via TCP/IP (webservices/whatever).
>
> Is there a trick to checking what connection(s) are avaliable?
>
> Is there a way to override the default gateway according to what is
> avaliable?
>
> What needs/can be programmed manually, and what can be configures within
> Windows CE?
>
> Thanks,
> Finn Johnsen
>

Also, the OS knows the 'cost' of communicating on each type of connection
and will automatically prefer LAN-type connections to dial-up-type
connections when both are present and active. That is, if your IP address
on WLAN is 1.2.3.4 and you IP address on GPRS is 5.6.7.8 and you try to
communicate with a device whose IP is 9.8.7.6, the OS will choose WLAN,
assuming that you have a gateway on both systems, as it will presume that
WLAN is higher-performance. Of course, if you try to contact 5.6.7.55, it
will use GPRS, since the target is on the same subnet as that adapter.

What have you tried and what went wrong to precipitate the question? I
think that it should basically just work...

Paul T.

"Alex Yakhnin [MVP]" <(E-Mail Removed)> wrote in message
news:8EF8AB06-0B72-4758-BDBC-(E-Mail Removed)...
> If you want to know if you're connected to WLAN you can just simply hit
> some
> known web host in your LAN and see if you get a response. For
> programmatically connecting with GPRS you'd need to use RAS or ConnManager
> API's.
>
> For a free ConnManager implementation you can use SDF:
>
> www.opennetcf.org/sdf
>
> For a not so free, but full solution you can use:
>
> http://www.intelliprog.com/netcf/ras.html
>
> --
> Alex Yakhnin, .NET CF MVP
>
> "Finn J Johnsen" wrote:
>
>> Hi
>>
>> I've got a device with both GPRS and WLAN. I want my app to use the the
>> WLAN preferably, and GPRS if a WLAN connection is unavailable.
>>
>> Looking for tips on how to best solve this problem. Only my app is to
>> contact the "world" via TCP/IP (webservices/whatever).
>>
>> Is there a trick to checking what connection(s) are avaliable?
>>
>> Is there a way to override the default gateway according to what is
>> avaliable?
>>
>> What needs/can be programmed manually, and what can be configures within
>> Windows CE?
>>
>> Thanks,
>> Finn Johnsen
>>

Usually your application opens conceptual destination such as 'The
Internet' or 'My Work Network' to let OS choose appropriate connection
for you. Users can configure their connection preference
(GPRS/WLAN/whatever) for each destination using standard setting tool.


Stefan


Finn J Johnsen wrote:
> Hi
>
> I've got a device with both GPRS and WLAN. I want my app to use the the
> WLAN preferably, and GPRS if a WLAN connection is unavailable.
>
> Looking for tips on how to best solve this problem. Only my app is to
> contact the "world" via TCP/IP (webservices/whatever).
>
> Is there a trick to checking what connection(s) are avaliable?
>
> Is there a way to override the default gateway according to what is
> avaliable?
>
> What needs/can be programmed manually, and what can be configures within
> Windows CE?
>
> Thanks,
> Finn Johnsen

Paul G. Tobey [eMVP] wrote:
> Also, the OS knows the 'cost' of communicating on each type of connection
> and will automatically prefer LAN-type connections to dial-up-type
> connections when both are present and active. That is, if your IP address
> on WLAN is 1.2.3.4 and you IP address on GPRS is 5.6.7.8 and you try to
> communicate with a device whose IP is 9.8.7.6, the OS will choose WLAN,
> assuming that you have a gateway on both systems, as it will presume that
> WLAN is higher-performance. Of course, if you try to contact 5.6.7.55, it
> will use GPRS, since the target is on the same subnet as that adapter.
>
> What have you tried and what went wrong to precipitate the question? I
> think that it should basically just work...

Excellent, thanks.

I'm just doing research how this can be handeled. I'm predicting I'll
get this question myself, and now I'll simply quote a mr Paul Tobey.

regards,
Finn

Stefan Hong wrote:

> Usually your application opens conceptual destination such as 'The
> Internet' or 'My Work Network' to let OS choose appropriate connection
> for you. Users can configure their connection preference
> (GPRS/WLAN/whatever) for each destination using standard setting tool.

No, we need the system to be as "embedded -looking" as possible, We can
not have users touching anything outside the (main) app.

We'll have to disable "explorer" (taskbar), desktop icons etc. So I'll
have to set up Networking once (on release), or control this through the
app.

thanks anyway,
Finn