Which protocol is connectionless and provides unreliable service for short messages?

Which protocol is connectionless and provides unreliable service for short messages?

• A. TCP
• B. UDP
• C. IGMP
• D. ARP

Answer: (B)

Connectionless delivery with no reliability guarantees defines UDP. It sends data as independent datagrams without establishing a session and without guaranteeing delivery, ordering, or error-free transmission. This gives UDP very low overhead and fast delivery, making it ideal for short messages where speed matters and occasional loss is acceptable. Applications like DNS queries or real-time communications often rely on UDP for this reason. In contrast, TCP is connection-oriented and provides reliability and ordering; IGMP is about joining multicast groups, and ARP maps IP addresses to MAC addresses on a local network. So the protocol described is UDP.

Connectionless delivery with no reliability guarantees defines UDP. It sends data as independent datagrams without establishing a session and without guaranteeing delivery, ordering, or error-free transmission. This gives UDP very low overhead and fast delivery, making it ideal for short messages where speed matters and occasional loss is acceptable. Applications like DNS queries or real-time communications often rely on UDP for this reason. In contrast, TCP is connection-oriented and provides reliability and ordering; IGMP is about joining multicast groups, and ARP maps IP addresses to MAC addresses on a local network. So the protocol described is UDP.