Hello,

I’m testing a midlet that I developed for a Nokia 3650 phone. It’s an IM client that registers with a web service, to store presence info, creates a Datagram connection on a particular UDP port, and waits for messages to come. The web service that the IM client registers with collects the IP address (i.e., getRemoteAddr()) of the phone and stores it in memory.. This IP address is provided to other IM clients seeking to send messages to the phone.

It’s simple, mildly interesting, and totally works on various J2ME phone emulators…

Unfortunately, in the course of testing the midlet on a REAL phone, I’m finding that the IP address assigned to the phone is constantly changing. Here’s an excerpt of a tomcat log showing how the phone’s IP address is different from on registration to the next:

2003-07-22 16:10:42 RegisterServlet: Phone 5551234 registered with IP address 209.183.48.35
2003-07-22 16:10:55 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.39
2003-07-22 16:11:06 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.53
2003-07-22 16:11:15 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.37
2003-07-22 16:11:26 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.45
2003-07-22 16:11:36 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.45
2003-07-22 16:11:47 RegisterServlet: Phone 5551234 re-registered with IP address 209.183.48.37
2003-07-22 16:13:55 RegisterServlet: Phone 5551234 unregistered

Surprise Surprise!! The phone’s IP address changed (at least) 6 times in ~3 minutes!! After reading some of FAQs and white papers on GPRS, I was under the impression that the IP address assigned to the handset for a given PDP Context would remained fixed for anywhere from 1 to 4 hours depending on usage…

Does anyone know if there’s some configuration option that enables this? Would a custom APN and/or Fixed-End connection make the phone’s IP address fixed?

Thanks in advance,

Jackson Wynn
Znq3, Inc.
jwynn@znq3.com