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November 23, 2004

Using the blackberry 7100t's GPRS modem

The 7100t doesn't have a bluetooth modem but as Paul Billings remarked in previous comments, you can use the modem through the usb cable. The instructions can be found here, and worked well for me. The connectivity seemed OK, but I wanted to compare it to my windows 2003 smartphone, which I used before I got the 7100t and which supports the modem through bluetooth. Both devices have T-Mobile accounts.

blackberry 7100t24 kbps5 kbps
XPhone Windows 200339 kbps10 kbps

This is using the tests from

This confirmed the user experience I had with the two devices. The smartphone loads bloglines mobile edition notacibly faster than the blackberry. I first thought that this was maybe a slow rendering issue, but it now appears as that the network plays a role in this also. Does the blackberry go through some proxy server that is maybe highly loaded, is the radio less efficient, or is maybe the IO infrastructure of the blackberry inferior or the smartphones?

To me it appears that there is some blocking proxy in the network architecture, as you can only use http & pop (and probably a few other protocols such as imap) when you connect over de blackberry's modem. Ftp, telnet and icmp are not relayed. I wouldn't be suprised if that proxy also had a limiting effect on the bandwitdth. The service on the smartphone allows telnet, icmp, etc.

The result is that it all works, but in a kind of impared manner, when compared to other device from the same carrier.

Posted by Werner Vogels at November 23, 2004 02:07 AM


Your Trackback doesn't seem to be working, when I try and ping it I get this error:

Pinging HTTP/1.1 404 Not Found Content-Length: 1635 Content-Type: text/html Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET Date: Tue, 23 Nov 2004 16:55:23 GMT Connection: close

Posted by: Stuart on November 23, 2004 11:57 AM

Thanks for posting this! I found it via, and never would have known about this functionality otherwise.

I have a 7100t, and assumed that since Bluetooth GPRS modem functionality wasn't there that it wouldn't work over USB either. I never bothered to try.

I've got it working great now, and I've posted about it at here:

Thanks again,

Josh Bancroft
Editor -

Posted by: Josh Bancroft on November 23, 2004 04:25 PM

Yes, I believe all comm via Blackberry goes through a proxy - and this will definately impact performance.

(I have a 7290 on order) - while RIM has disabled all Bluetooth profiles but headset - I've noticed in the development API SDK that they have a section for serial Bluetooth communications. SLIP/PPP anyone?

Posted by: Jason Kaczor on November 23, 2004 05:10 PM