In a TCP communication, the checksum field within the TCP header is used to ensure data integrity for end-to-end communications. The checksum provides end-to-end error detection between the source and destination application and is tested when received by the intended application. This means that it checks for errors across the ntire path of the communication. If the checksum fails, the receiver will not accept the segment but will inform the sneder to resend the segment that was not received correctly.
