Not able to connect to TCP server through APN - sockets

Question

After googling thoroughly I finally decided to post my problem which is really giving me nightmares.
In my app I am trying to connect to a TCP server using the Network Carrier internet and using following connection string:
url="socket://"+ip+":"+port+";deviceside=true;connectionTimeout=30000;apn=;tunnelauthusername=;tunnelauthpassword=;";
I am able to connect to internet through the phone's browser but not able to connect to TCP server through app.
In my device APN authentication is disabled by default and APN,Userid/Password fields are blank thats why i have taken these parameters as blank valued in the connection string.
When i try to connect through wifi network using the string below:
url="socket://"+ip+":"+port+";deviceside=true;interface=wifi;connectionTimeout=30000";
I am able to connect to server but not in the case via APN.
Please help me out.
I am just stuck here and finding no way out.
Thanks

Answer 1

There are a variety of methods of connecting to a Server. What you are doing is specifying the method to use in the connection suffix which you set. The options that you can use in the connection suffix are documented in the BB KB article here:
Different-ways-to-make-an-HTTP-or-socket-connection
If you are supporting really old phones (pre OS 5.0), then this is the only option you have. But the trick with this is that you have to figure out what connection method is going to work on your device at the time you make the request. There is a load of code floating round the internet to do this, most of it dubious.
If you are OS 5.0 or above, then you can use a more advanced API, the ConnectionFactory, to make this easier, and in OS 6.0 even more advanced features. These are all documented on the BB Java microsite, see here:
BB OS Networking
The option you are using is the GCF framework. I recommend you investigate the "Network API" if you are supporting OS 5.0 and later only. You might also investigate the "Network API alternative for legacy OS".
This does not answer the frequent question, "how come the Browser can connect and I can't in my app?". This is because the Browser uses a special BlackBerry connectivity method referred to as BIS-B. The good thing about BIS-B is that it will work for any BB phone that has a BlackBerry tariff, and requires no configuration. The bad thing is that you do not get access to it as of right. To get access to it, the easiest thing to do is to ask for Push support, even if you are not planning on using it immediately but might in the future. This is documented on the page above.
But back to your question. The APN values in your TCP configuration being not set, does NOT mean you don't have to set them. The values specified in the Options are used as the default values should someone code ";deviceside=true" as a connection string - the idea being that users can set these for themselves and application developers don't code anything. These values are specific to your carrier. So search to find out what values you need to use. You will either put these values in the TCP Options (and so don't code them in your connection suffix), or put in your connection suffix. If you can't find out what you should put in there, you need to ask your carrier.
On most BlackBerry tariffs, using direct TCP through the APN may cost the user something for the data, and will also require configuration. Alternatively, you can use WAP 2, which may also cost for data, but doesn't require any configuration. The advantage of both these is that they will work on phones that are not using a BlackBerry tariff.
My recommendation is to look at connecting using ConnectionFactory (Network API), but this will only work for OS 5.0 and above.