The transport layer in the OSI model is responsible for end-to-end communication and includes two main protocols: TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) .

IP (Internet Protocol) : Works at the network layer and is responsible for routing packets across networks.

ARP (Address Resolution Protocol) : Works at the network layer and maps IP addresses to MAC addresses.

TCP : A connection-oriented protocol at the transport layer that ensures reliable communication through acknowledgments and retransmissions.

UDP : A connectionless-oriented protocol at the transport layer that provides faster but less reliable communication compared to TCP.

Since the question specifies a connectionless-oriented protocol at the transport layer, the correct answer is UDP .

HCIA Huawei ACCESS Official Documentation , Chapter: Transport Layer Protocols.

TCP/IP Protocol Suite Overview by Huawei.