SCTP States Initiation.data transfer.shutdown Client Server Client Server SYN INI SYN-ACK INIT-ACK ACK COOKIE-ECHO COOKIE-ACK M Conversation Conversation TCP SCTP
SCTP States ◼ Initiation, data transfer, shutdown
INIT and INIT-ACK chunk ■ A list of all IP addresses that will be a part of this association An initial transmission sequence number(TSN)that will be used to reliably transfer data An initiation tag that must be included on every inbound SCTP packet ◆ The number of outbound streams that each side is requesting The number of inbound streams that each side is capable of supporting
◼ INIT and INIT-ACK chunk
state cookie all the information needed by the sender of the INIT-ACK to construct its state transmitted to the sender in the INIT-ACK chunk
◼ state cookie all the information needed by the sender of the INIT-ACK to construct its state transmitted to the sender in the INIT-ACK chunk
■COOKIE-ECHO allowing the SCTP receiver to fully construct its state ■COOKIE-ACK acknowledges that setup is complete Both chunks in the COOKIE sequence can also include data traffic
◼ COOKIE-ECHO allowing the SCTP receiver to fully construct its state ◼ COOKIE-ACK acknowledges that setup is complete ◼ Both chunks in the COOKIE sequence can also include data traffic
Data Transfer Client Server Client Server Listen State Chunk A A Stream A(SID=1) Chunk A TSN=n SSN=m SYN Seq=m SYN SYN Chunk B Stream B(SID=2) Chunk B Sent Received TSN=n+1 SSN=m SYN Seq=n ACK m+1 Chunk C Stream C(SID=3) ESTAB Chunk C TSN=n+2 SSN=m Stream D(SID=4) Seq-m+1 ACK n+1 Chunk D ChunkD TSN=n+3 SSN=m ESTAB Conversation Association
Data Transfer