Trying some basic device-to-device communication, but from what I can see, T-Mobile blocks ports (NAT, firewall, whatever)...

Connecting Out from the device (on 3g), works fine, connecting to the device doesn't... It looks like it gets a legit IP address (outgoing connections report a 208.54.*.* address, but telnets/nmaps/pings to that address never come back...

Any thoughts? Anyone know any ports TMobile leaves open? Or of any way to connect device-to-device?

the emulator of android is working on 5554
if u open second emulator u get port 5556
so default port is 5554

The mobile network of t-mobile probably is behind one big giant huge NAT, so you can't connect from device to device, with out the use of other techniques, like a server or STUN.

kali wrote:the emulator of android is working on 5554
if u open second emulator u get port 5556
so default port is 5554

This is irrelevant to the question, he asks about the device, not the emulator .

Yeah, I figured it had to be NAT'd, guess its back to a server in the middle...
There was XMPP/GTalkAPI in 0.9 that would have done exactly what I wanted, but alas!

Yeah, it's a pitty they removed it from the SDK. Though xmpp also works over a central server.

Yeah, so does/did GTalkAPI, but it was at least transparent to the developer, all nicely wrapped in functions =P

Just hate having to write networking code when tests show that a good number of packets get dropped on 3G, makes it tough to do it cleanly