UDP Checksum(Cont) Receiver Compute checksum of received segment Check if computed checksum equals checksum field value: k No-error detected k yes- no error detected But maybe errors nonethless? 2021/2/8 11
UDP Checksum (Cont.) Receiver: Compute checksum of received segment Check if computed checksum equals checksum field value: NO - error detected YES - no error detected But maybe errors nonethless? 2021/2/8 11
Introduction to TCP Communication abstraction reliable k Ordered Point-to-point Byte-stream Full duplex Flow and congestion control Protocol implemented entirely at the ends k Fate sharing 2021/2/8 12
Introduction to TCP Communication abstraction: Reliable Ordered Point-to-point Byte-stream Full duplex Flow and congestion control Protocol implemented entirely at the ends Fate sharing 2021/2/8 12
Original TCP/IP(Cerf Kahn) No separation between transport (tcp)and network(IP)layers One common header Use ports to multiplex multiple tCP connections on the same host 32 32 16 16 8n Source/Port Destination/Port Window ACK Text Byte- based sequence number Flow control but no congestion control 2021/2/8 3
Original TCP/IP (Cerf & Kahn) No separation between transport (TCP) and network (IP) layers One common header Use ports to multiplex multiple TCP connections on the same host Byte-based sequence number Flow control, but no congestion control 2021/2/8 13 Source/Port Destination/Port Window ACK Text 32 32 16 16 8n
Today's TCP/IP Separate transport(tCP)and network(P layer k Split the common header in TCP and UDP headers Fragmentation reassembly done by IP Congestion control 2021/2/8 14
Today’s TCP/IP Separate transport (TCP) and network (IP) layer Split the common header in: TCP and UDP headers Fragmentation reassembly done by IP Congestion control 2021/2/8 14