Window flow control: send side Packet Sent Packet Received Source Port Dest, Port Source Port Dest. port Sequence Number Sequence Number Acknowledgment Acknowledgment HL/Flags Window HL/Flags Window D Checksum Urgent pointer D Checksum Urgent Pointer Options Options App write acknowledged sent to be sent outside window ecture 17: TCP& Congestion Control8 Lecture 17: TCP & Congestion Control acknowledged sent to be sent outside window Source Port Dest. Port Sequence Number Acknowledgment HL/Flags Window D. Checksum Urgent Pointer Options… Source Port Dest. Port Sequence Number Acknowledgment HL/Flags Window D. Checksum Urgent Pointer Options... Packet Sent Packet Received App write Window Flow Control: Send Side