How can an iOS app keep a TCP connection alive indefinitely while in the background?

Question

An iPhone app, connecting to a remote server via TCP. The use scenarios are:

1. app (user) sends data to server and server responds data back.
2. server mig

Answer 1

For when the app is in the foreground:

Look at STOMP http://stomp.codehaus.org/Protocol

The STOMP Framework in Obj-C http://code.google.com/p/stompframework/

and the ActiveMQ broker http://activemq.apache.org/

For when the app is in the background I would probably go for using APNS (Notifications) to prompt the user to wake the app back up...