TCP is a protocol in the transport layer of the TCP/IP model.
State one role of TCP when data is transmitted over a network.
Mark scheme
Award one mark for any of the following up to a maximum of one mark:
- Breaks messages/data into packets (1)
- Reassembles packets (at the destination) (1)
- Detects errors (1)
- Resends lost/missing packets/requests retransmission of lost packets (1)
- Creates/establishes a connection between two computers/hosts/sets up a connection before data is sent (1)
Do not accept routing packets or using IP addresses, which is the role of IP.
Do not accept encrypting data or providing security.
Do not accept vague answers such as 'transmits data' or 'sends data' without saying how TCP does this.
Example answers and how they were marked
Full marks1/1
It splits data into packets.
Why: States that TCP breaks data into packets.
No marks0/1
It routes packets between IP addresses.
Why: Near-miss: routing packets is the role of IP, not TCP.
No marks0/1
It encrypts data so it is secure.
Why: Encryption is not a role of TCP, so no creditworthy point.