TCP vs. SCTP Protocols

Difference Between TCP and SCTP Protocols

TCP or Transmission Control Protocol is known for the reliable data transfer. Along with SCTP or Stream Control Transmission Protocol, it lies in the transport layer. TCP is very reliable when it comes to reliable data transfer. However, there are some Internet applications which may not necessarily need 100% sequence delivery packets but a reliable transfer. At those times, TCPs only cause network latency while transporting the data packets.  To rule out this, SCTP is used to transport PSTN signaling over IP.

TCP:

TCP is an end to end connection oriented reliable protocol. It enables guaranteed data transmission via single streaming. The main features of TCP are 3 way handshake (SYN, SYN-ACK, and ACK), Error Detection, Slow Start, Flow Control and Congestion Control enable reliable transmission of data packets even in peak hours and congestion times.

Standard example of well known TCP applications and port numbers are FTP data (20), FTP Control (21) , SSH (222) ,Telnet (23) , Mail (25), DNS (53), HTTP(80),POP3(110),SNMP(161) and HTTPS(443).

SCTP:

SCTP, like TCP and UDP is an IP transport protocol.  It is a unicast protocol and enables end -to -end data termination within two endpoints having more than one IP addresses.  It is a full duplex transmission protocol and endorses features like retransmitting, flow control and sequence maintenance.

On top of TCP, SCTP has more features and some are listed below

  • SCTP Multi-Streaming Feature

Contrary to TCP, SCTP divides data into multiple streams with a sequence of allocated delivery to each one.  In case of VoIP or Telephony signaling, the sequence of packets should be maintained. So, SCTP allows multiple streaming of signals, resulting in better performance.

  • SCTP multi homing

The several redundant routing paths and multiple IP addresses maintain the availability of the endpoint for a single SCTP endpoint.

  • Path selection

A counter monitors the track of unsuccessful transmission to a destination and if the unsuccessful data exceeds the threshold amount defined, that address becomes inactive and data is then, sent to other alternative address.