Just wanted to point out that the "Connect Back" feature is actually unnecessary...the original 0.4 Gnutella protocol specification is sufficient!

I had *great* results with BearShare by just advertising pongs when I want a connect back.

This is how we implemented auto-detect of firewalled status.

BearShare lets loose with pongs for up to 1 full minute (per hour). If it gets "ins" then we aren't firewalled, else we are firewalled.

You can see the state transitions in BearShare 3.0.0 by putting the cursor over the Hosts LED and observing the messages in the balloon; e.g. "Ponging for incoming connections"

Also, the Network balloon shows some other states, like the firewalled detection progress.

BearShare 2.6.x has these features as well, but lacks the enhanced feedback in the indicator area.

I highly recommend anyone who is interested in implementing connect-back features seriously think about just using pongs to entice other servents into providing a connect back.