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ServerSocketConnection: what's the address that others can connect?

HaoZhe Xu
Ranch Hand

Joined: Nov 03, 2003
Posts: 222
Hello everyone, I have to create a server in a midlet and connect to the server mobile phone with another client mobile phone, when I use:
(ServerSocketConnection)"socket://"); // or specify a port number
getLocalAddress returns, which is just the localhost, so how do I create a server socket that has an inbound address(in a 3G network or GPRS network)?

I also tried push registry, however, it seems to be the same, I followed the instruction in:

the question is, what is the address that others can connect to you?

Thanks a lot!

Tim Holloway
Saloon Keeper

Joined: Jun 25, 2001
Posts: 17417

Think of your mobile phone as a desktop computer, Other people's phones are also desktop computers in this visualization. When networking desktop computers together, you use a switch device.

In the case of mobile phones, the "switch device" is the phone company, and it's usually going to assign your mobile an IPv4 address using DHCP protocol. There's generally no way to predict what that address will be, and it will probably be different at different times.

What desktop computer usually do in a case like that is determine their IP address and push it out to a public DNS service like so that others can locate you. However, since it's probably going to be a NAT address, you probably won't have a globally unique IPv4 address. Plus, there's a chance that the phone company won't route inbound connection requests to your phone.

As you found out, "localhost" resolves to If you dig around a little, you can probably find your phone's hostname, and if you look up using that name instead of localhost, you'll probably get your actual assigned IP address.

An IDE is no substitute for an Intelligent Developer.
I agree. Here's the link:
subject: ServerSocketConnection: what's the address that others can connect?
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