1. SCTP: Stream Control Transport Protocol
Albert Phouangaphay
Alejandra Coca
Devin Syas
Dominic Ajagba
Michael Gibson
Zach Windon

2. Strategy Overview: Topics: Explain how we will cover SCTP
Devin: 2 minutes
Topics:
What is SCTP?
Albert: 3 minutes
Main Features of SCTP (3 parts)
Michael: 3 minutes
Dominic: 3 minutes
Alejandra: 3 minutes
Pros and Cons of SCTP
Zach: 3 minutes
Conclusion
Devin: 3 minutes
Strategy

3. Introduction

4. What is SCTP? Message-oriented Transport-level Protocol
Similarities to TCP
Unicast, connection-oriented protocol
Sequential packet delivery
Rate-adaptive congestion control
Capable of handling multiple simultaneous streams
Provides for multihoming

5. History Doubt in TCP began in 1991
Attempts for reliable communication over UDP began
MDTP began in 1997 and was submitted to the IETF in 1998
SIGTRAN formed to move telephone signaling protocols to IP
Defined in RFC 2960, October 2000
Updated by RFC 4960, September 2007

6. Main Features of SCTP

7. Unicast With Multicast Properties
Point-to-point protocol but can use several addresses at the same end host
Uses different paths to reach the end host
TCP breaks if the transport path breaks, unless the IP protocol corrects it

8. Reliable Transmission
Uses checksums and SACK to detect corrupted, damaged, discarded, duplicated and reordered data
Can retransmit data as necessary
More resilient than TCP about reordered data
Faster pickups

9. Message Oriented Similar to how UDP transports messages
Each message can be framed to keep tabs on the structure and order of the datastream

10. Rate Adaptive Cooperates and co-exists with TCP for bandwidth
Scales up and down based on network load conditions (like TCP)
Same algorithms for slow starting if packets lost

11. Multi-homing Main difference to TCP
End-node can be reachable by more than one transport address
If system fails, traffic is redirected to another path
TCP:
SCTP:

12. Multi-streaming SCTP stands for Stream Control Transmission Protocol
Data is sent in multiple streams, each one with an identifier
Losing one stream does not affect the others
TCP only uses one stream

13. Association Initiation
To initiate communication 4 messages are used:
INIT: client sends initiation message for association
INI-ACK: server sends message to show the first one reached and adds a cookie (connection identifier)
COOKIE-ECHO: client replies with same cookie
COOKIE-ACK: server organizes resources and answers with message
INIT collision resolution to avoid several simultaneous SCTP connections

14. Pros and Cons of SCTP

15. Pros
With SCTP’s multihoming feature, network failures or changing conditions in the network can be dealt with by routing around the issues
SCTP has reliable transport, meaning that all the data units sent through the network will make it to the desired end point
SCTP can have multiple streams of data at the same time in between two endpoints that have a connection in a network

16. Cons
SCTP requires changes in the transport stack, applications may need modification to operate SCTP rather than TCP or UDP
Applications also may need to be modified to be able to handle multiple streams going simultaneously
SCTP has not yet been fully implemented in some operating systems like Microsoft operating systems

17. Conclusion

18. Real World Application
Used as an alternative to TCP and UDP for more secure transport with more features available
Widely used in the telecom industry
All major operating systems have SCTP implementation

19. Comparison table between SCTP, TCP and UDP

20. Future of SCTP
Demand for SCTP is increasing due to its wider variety of services compared to conventional protocols
Most likely will not beat TCP because the extra features are not worth overcoming implementation issues
Several unique attributes built in to SCTP on the transport layer can be emulated in TCP on the application layer
Reference Randall Stewart Isoc.org
Give multi-homing example

21. Sources