Rainbow Electronics W90N740 User Manual
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W90N740
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NAT Masquerading IP Address Registers (MASADx) (x : 15 ~ 0)
NAT Masquerading Port Number Registers (MASPNx) (x : 15 ~ 0)
Local Station IP Address Registers (LSADx) (x : 15 ~ 0)
Local Station Port Number Registers (LSPNx) (x : 15 ~ 0)
The {MASADx, MASPNx} is represented for the outside IP address and the port number.
The {LSADx, LSPNx} is represented for the internal IP address and the port number.
A private network is set up with its own public IP address (MASADx) and port number (MASPNx) for
external access. It means that when a local station wants to sent a packet outside via the NAT
module, the packet is transmitted to external MAC port with its source address and source port
number replaced by MASADx and MASPNx.
On the other hand, when the external MAC receive packet, its destination address and destination
port number is compared. If the result is hit, then its destination address and destination port number
are be replaced by LSADx and LSPNx, and the packet is transmitted to local MAC.
7.6.2.8 MASADx,
LSADx
31
30
29
28
27
26
25
24
IP Address Byte 4 (Most Significant Byte)
23
22
21
20
19
18
17
16
IP Address Byte 3
15
14
13
12
11
10
9
8
IP Address Byte 2
7
6
5
4
3
2
1
0
IP Address Byte 1
MASPNx, LSPNx
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
Port Number
7
6
5
4
3
2
1
0
Port Number
For example, if the masquerading address is 140.112.2.100 and the masquerading port number is 7500,
then the value in MASAD is 8C-70-02-64, and the value in MASPN is 00-00-1D-4C.