SCTP (Stream Control Transmission Protocol) heartbeat mechanism works by allowing SCTP endpoints (hosts) to periodically exchange heartbeat messages to confirm the liveliness and availability of each other. These heartbeat messages are part of SCTP’s association maintenance procedures and help detect if a peer endpoint becomes unreachable due to network failures or host failures. If an endpoint stops receiving heartbeat messages from its peer within a specified timeout period, it considers the peer unreachable and may take appropriate actions, such as attempting to re-establish the association or switch to an alternative path if multihoming is enabled.
SCTP (Stream Control Transmission Protocol) operates as a reliable, message-oriented transport protocol designed for applications requiring reliable and ordered delivery of messages. SCTP establishes associations between endpoints, allowing them to exchange data in multiple streams within a single connection. SCTP uses a four-way handshake for association setup, exchanging parameters such as port numbers, verification tags, and initial sequence numbers. Once an association is established, SCTP ensures reliable delivery of messages by using acknowledgments, retransmissions, and congestion control mechanisms to maintain data integrity and flow control.
SCTP multihoming enables an endpoint (host) to have multiple IP addresses associated with it, allowing for increased fault tolerance and network resilience. In SCTP, multihoming works by allowing an endpoint to maintain associations with multiple IP addresses simultaneously. Each association can use a different set of IP addresses, providing redundancy and load balancing capabilities. If one IP address becomes unreachable or fails, SCTP can switch to an alternative IP address associated with the same endpoint without interrupting ongoing data transmission. This flexibility enhances SCTP’s reliability in environments where network connectivity and availability are critical.
TSN (Transmission Sequence Number) in the SCTP protocol is a 32-bit field used to uniquely identify and order data chunks exchanged between SCTP endpoints within an association. TSNs are assigned sequentially by the sending endpoint and are used to detect duplicate data chunks, ensure ordered delivery of messages, and manage flow control within the SCTP association. Each chunk of data transmitted over SCTP includes a TSN, allowing receiving endpoints to reconstruct the original message order and detect any lost or out-of-sequence data chunks. TSNs play a crucial role in maintaining message integrity and reliability in SCTP’s message-oriented communication model.