Which feature is commonly associated with SCTP and can help reduce head-of-line blocking in some scenarios?

• A. Multi-streaming
• B. Multi-homing
• C. Message-oriented reliable delivery
• D. Connectionless datagram service

Answer: (A)

The idea being tested is that SCTP can carry multiple independent streams within a single connection, and those streams have their own sequencing. Because each stream is ordered separately, a delay or blockage on one stream doesn’t hold up data on the others. In practice, this means you can send different kinds of data—like control messages on one stream and bulk data on another—and even if the data on the first stream arrives late or stalls, the messages on the second stream can still be delivered in a timely fashion. That reduces head-of-line blocking compared to a single, all-data-in-order channel.

Understanding why this helps: head-of-line blocking happens when a single in-order delivery queue blocks subsequent data. With multiple streams, the constraint is per-stream rather than across all data. So progress can continue on some streams while others pause, which is especially beneficial for multiplexed workloads or mixed-traffic patterns.

Multi-homing is about path redundancy and resilience, not reducing blocking within a connection. Message-oriented reliable delivery describes SCTP’s reliability and the fact that it preserves message boundaries, but the key improvement for HOL blocking comes specifically from the parallel streams. Connectionless datagram service is not a characteristic of SCTP, which is connection-oriented and reliable.