Why SCTP is used in S-GW in LTE architecture instead of TCP which is widely used?

Question

I want to know TCP is very useful protocol for connection establishment. In LTE why we use SCTP, not TCP.
Can anybody explain why it is so?

Answer 1

I want to make your clear that most of the SGW applications runs over the UDP protocol. UDP ports 2123 and 2152 are used for control and data respectively. As per my knowledge SGW has following three interfaces.
S11 -Interface with MME which is primarily used for session/bearer establishment.
S5 - Interface with Home network PGW
S8 - Interface with Visited network PGW

Only the interface towards PCRF which is based on Diameter uses TCP/SCTP. SCTP is better than TCP in many terms that's why it is used as transport protocol. Diameter uses 3868 standard port for communication with its peer.