What is the difference between SCTP and TCP?

Let us begin by learning about Stream Control Transmission Protocol (SCTP).


SCTP represents Stream Control Transmission Protocol. It is a new stable, message-oriented transport layer protocol. It is universally produced for Internet applications that have been introduced. These new applications include IUA (ISDN over IP), M2UA and M3UA (telephony signaling), H.248 (media gateway control), H.323 (IP telephony), and SIP (IP telephony), etc.

SCTP connects the characteristics of UDP and TCP. SCTP is a stable message-oriented protocol. It protects the message boundaries, and simultaneously, detects hidden data, duplicate information, and out-of-order data. It also has congestion control and flow control architectures.

The unit of data in TCP is a byte. Data transfer in TCP is reserved by numbering bytes by utilizing a sequence number. Otherwise, the unit of data in SCTP is a DATA block that can or cannot have a one-to-one relationship with the message appearing from the process due to fragmentation.

In SCTP, there can be multiple streams in each association. Each stream in SCTP is required to be recognized by using a stream identifier (SI). Each data chunk should carry the SI in its header so that when it appears at the destination, it can be suitably located in its stream.

SCTP also supports for multihoming in that the end points can use several IP addresses for the connection. The SCTP connection endpoints can use IP addresses from multiple ISPs for network-level fault tolerance. If, during the link, one of those ISPs were to decline, the connection can only use the IP address from the operational ISP for the connections.


TCP represents Transmission Control Protocol. It is a transport layer connection-oriented protocol. It supports a reliable connection and protected data transmission between the connecting devices over the network. It can create a secure connection and then send the data.

TCP sends the data from one machine to the other in the form of data blocks. It is entirely slow in data transmission but has more services including flow control, error control, and congestion control in the system. The TCP header is of 20-60 bytes and hence includes several elements of information to improve the reliability, but the overhead is increased.

TCP supports adequacy by providing the connection-oriented end-to-end adequate packet delivery by internetwork. It sequences the bytes with a promoting acceptance number that indicates the destination to the next byte the source forecast to obtain. If an acknowledgment for packets is not obtained in a definite period, these are retransmitted.

TCP also displays how to receive some packets in sequence at the destination without overflowing the internal buffer. TCP enables full-duplex operation so that sender & receiver both can connect simultaneously.