What is the difference between SCTP and UDP?

Let us begin by understanding what Stream Control Transmission Protocol (SCTP) is.


SCTP represents Stream Control Transmission Protocol. It is a new stable, message-oriented transport layer protocol. It is frequently designed 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 structures.

In TCP, there is only one flow in each connection. In SCTP, there can be multiple flows in each association. Each stream in SCTP is required to be identified by using a stream identifier (SI).

Each data chunk should carry the SI in its header so that when it occurs at the destination, it can be suitably placed in its stream. The 51 is a 16-bit number beginning from O.


UDP represents User Datagram Protocol. It is a transport layer connectionless protocol. It supports the fast transmission of data between the connecting devices over the network. There is no overhead of generating, maintaining, and removing a connection in UDP.

It can be generally used to send real-time data where it cannot afford some transmission delays. UDP sends the data from one device to the other in the structure of constant data flows.

The UDP header is of constant size, i.e., 8 bytes. It is unreliable but quicker in speed. Because of its transmission speed, protocols such as DNS, DHCP, RIP, etc., use UDP for accurate data transmission over the network.

UDP is an unreliable protocol. It will require a UDP protocol in some terms. The UDP is deployed where the packets needed a huge amount of bandwidth along with the basic information.

For example, in video streaming, accepting hundreds of packets is troublesome and misused bandwidth. Some packets hidden cannot generate a problem in video streaming, and it can also avoid it.

UDP is also used by applications that generally transmit a small amount of information at one time.

For instance, UDP supports a protocol port to categorize between several programs implementing on an individual device. Each UDP message includes both a destination port number and a source port number.

This makes it applicable for the UDP software at the destination to deliver the message to the proper application program and for the application program to send an acknowledgment.