Shouldn't be much of a problem. Current CICS versions have TCP/IP support built in. <br>The only other issue is whether your AIX Apps people are up to speed on socket<br>programming. Without more info., I'd be theorizing what's needed. But what we learned: <br><br>- Since speed is critical, you're talking more budget. That's a given. <br>- Avoid conversational transactions. <br> - Error recovery within a conversation is messy. <br>- If required, security will be your toughest problem. <br> - We have an OS/390 - Sun setup, and Top Secret (RACF) verfication from the Suns is a pain. <br> - Find yourself a RACF SAF manual and someone who knows 370 assembler.<br>- The transaction is only going to run as fast as the sum of the links in the data chain. - Fewer links = faster. <br> - Identify all the links before starting (TCP/IP, VTAM, shell, routers, disk, network...)<br> - In our case, we'd trip off security request to a RACF socket application. Get a reply. Then the data request. And wait for it to return. We should've beefed our design so the transaction verifiies the ID and grabs the data at one shot. We got a couple CPU upgrades because of that one. Our foul up, your gain. <br> <br>Hope that helps. Good luck. <br>