(Note: FWDs IAX support is currently in test phase so there will be interuptions. A lot of users have had problems connecting.)
You can get a free account to try JackenIAX for free at FreeWorldDialup FWD.
Enter your FWD phone number (NOT YOUR FWD USERNAME!) into the Account Name field, your FWD password into Account Password field and set host to iax.fwdnet.net
Don't forget to activate IAX in your account setting at FWD!
The CID Name and number is used to tell the recipient of your name and number. This information usually gets removed by your VoIP provider, so it's not really useful.
Try dialing 613 for an echo test to see that everything is working.
Give my test number a try, dial 748502
If you entered all information correctly, don't rule out that FWDs servers are down. This happens from time to time.
More to come...