According to my knowledge in SAP XI we have so many kind of

control levels to process the message. For instance i will

discuss on few points, like

1) Here using XI we can communicate with the SAP or Non-SAP

at sender side or reciever side.

2) XI supports both Syncronus and asyncronus communications

3) in XI we can find the status of the message where it is

during the process of Message processing.

4) We have so many kinds of monitoring techniques.

5) Here we can have N number of senders and N number of

recievers based on your requirement.

6) It supports to process multiple messages at a time from

different senders to multiple recievers.

So I feel we cant perform all these things in

Interfaces.That is the reason XI come into picture.