R2511-HP MSR Router Series ACL and QoS Configuration Guide(V5)

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TCP packet
TCP packet format
Figure 27 TCP packet format
Table 5 Description on the 6 flag bits in the TCP header
Fla
g
bit Descri
p
tion
URG The urgent pointer is valid.
ACK The acknowledgement number is valid.
PSH The receiver passes the data to the application layer as soon as possible.
RST Reset the connection.
SYN Synchronize sequence numbers to initiate a connection.
FIN The sender has finished sending data. This field terminates a connection.
TCP state transition
Figure 28 TCP state transition diagram
The protocols using TCP can be static or dynamic. Static protocols use fixed port numbers for interaction
and dynamic protocols use negotiated port numbers.
015
Data (if any)
Source port number Destination port number
31
Sequence number
Acknowledgement number
HLEN
TCP checksum
Option (if any)
Urgent pointer
Reserved
U
R
G
A
C
K
P
S
H
R
S
T
S
Y
N
F
I
N
Window size
39