Transport Layer - Panasonic DX-2000 Service Manual

10.4 Transport Layer

10.4.1 TCP (Transmission Control Protocol)
The TCP (Transmission Control Protocol) is an internetwork connection-oriented protocol that corresponds to the OSI Transport
layer. TCP provides full-duplex, end-to-end connections. When the end-to-end communication acknowledgement is not required,
the UDP (User Datagram Protocol) can be substituted for the TCP at the Transport (host-to-host) level. TCP and UDP operate at
the same layer.
The UDP is a connectionless oriented protocol.
Header Length
(4 bit)
DX-2000
The client (DX-2000) generates random sequential numbers initially and sends them to the server. The initial sequetial numbers are
synchronized with the clock and increments the counterevery 4 msec.
The Server responds with an acknowledgement that increments the initial sequential number by one. The ACK bit number is also
changed to a "1" value. The "SYN" can have and identical "ACK" response for each packet, thus, the server and the client can
establish a connection.
IP Header TCP Header
(20 byte) (20 byte)
TCP Segment in IP Datagram
Source Port (2 byte)
Sequence Number (4 byte)
Acknowledgment Number (4 byte)
Reserved Control Flag
(6 bit)
(6 bit)
Checksum (2 byte)
Option
Data (Segment)
TCP Segment Outline
TCP Header Monitoring Sample
TCP 3 Handshake General Flowchart
IP Datagram
TCP segment
Application D ata
(vary)
Destination Port (2 byte)
Window (6 byte)
Urgent Pointer (2 byte)
Increments No. sequentially
332
PAD
Server