ocr: ATypical TCP/IP Datagram FIGURE 1 Byte 0 - 16 44 0 Version Protocol Length Header Type Service of Total Length 4 Packet ID FF DM Fragment Offset IP 8 Time to Live Protocol Header Checksum Header 12 source Address 16 Destination Address 20 Source Port Destination Port 24 Sequence Number TCP 28 Acknowledgment Number Header 32 Data Olfset - Window 36 Checksum Urgent Pointer 40 Data The minimum sizes are shown. Both the IP and the TCP headers allow for optional data to follow the standard header with a maximum possible overall header length of 128 bytes (64 bytes each for IP and TCP).
