From an app_rpt/Allstar node, Echolink connections look just like Allstar/App_rpt connections except the Echolink node numbers have been prefixed with a 3 and padded out to 7 digits with leading zeroes. For instance, if you want to connect to Echolink node 1234 on your app_rpt system you would dial *3 followed by 3001234. If you have a 6 digit Echolink node number 123456, you would dial *3 followed by 3123456. As you can see we have reserved Allstar node numbers with a leading 3 for the Echolink number space.
For users originating from an Echolink node using Echolink supplied software, nothing changes for them, they just dial the 4 or 6 digit Echolink node number assigned to your app_rpt system and they get connected!