A transport-layer protocol for reliable, message-oriented data transport over IP networks. Initially designed for Signaling System 7 (SS7) message transport in telecommunications, the protocol combines the message-oriented features of the User Datagram Protocol (UDP) with the reliable, in-sequence delivery and congestion control of the Transmission Control Protocol (TCP). Unlike UDP and TCP, the protocol supports multihoming and redundant paths to enhance resilience and reliability. The Internet Engineering Task Force (IETF) standardized it in RFC 9260. The reference implementation was released as part of FreeBSD version 7 in 2008 and has since been ported to other platforms.
Key Features
The protocol offers several unique features that set it apart from other transport protocols.
- Message-Oriented: Supports message boundaries, ensuring that messages are delivered as complete units.
- Reliable Transport: Provides reliable, in-sequence delivery of messages with congestion control.
- Multihoming: Allows multiple network interfaces to be used for increased resilience and reliability.
- Redundant Paths: Supports redundant paths to ensure continuous data flow even if one path fails.
Standardization and Implementation
The protocol is standardized by the Internet Engineering Task Force (IETF) in RFC 9260.
- Reference Implementation: The reference implementation was released as part of FreeBSD version 7 in 2008.
- Portability: Since its initial release, the protocol has been widely ported to other platforms, ensuring broad compatibility and adoption.