Does XCOM perform any checksum over the data transmitted?
Release: XCOM..01300-11.6-XCOM Data Transport-for AIX
XCOM does not perform any checksum calculation over the data being transmitted. That sort of ckecking is not required at all because it is performed by the underlying communications protocol (TCP/IP) who is responsible to ensure that each packet received is an exact copy of the packet which was sent, as well as to ensure that all packets are delivered and that the target XCOM receives them in the correct sequence.
Whenever TCP/IP detects any error (checksum error or lost packet), the stacks themselves handle packet re-transmission as needed without any intervention by the client application (in this case, XCOM).