ZyXEL P-791R v2 Guia Do Utilizador
P-791R v2 Support Notes
9. What is SUA? When should I use SUA?
SUA (Single User Account) is a unique feature supported by P-791R v2 router
which allows multiple people to access Internet concurrently for the cost of a
single user account.
which allows multiple people to access Internet concurrently for the cost of a
single user account.
When P-791R v2 acts as SUA receives a packet from a local client destined
for the outside Internet, it replaces the source address in the IP packet header
with its own address and the source port in the TCP or UDP header with
another value chosen out of a local pool. It then recomputes the appropriate
header checksums and forwards the packet to the Internet as if it is originated
from P-791R v2 using the IP address assigned by ISP. When reply packets
from the external Internet are received by P-791R v2, the original IP source
address and TCP/UDP source port numbers are written into the destination
fields of the packet (since it is now moving in the opposite direction), the
checksums are recomputed, and the packet is delivered to its true destination.
This is because SUA keeps a table of the IP addresses and port numbers of
the local systems currently using it.
for the outside Internet, it replaces the source address in the IP packet header
with its own address and the source port in the TCP or UDP header with
another value chosen out of a local pool. It then recomputes the appropriate
header checksums and forwards the packet to the Internet as if it is originated
from P-791R v2 using the IP address assigned by ISP. When reply packets
from the external Internet are received by P-791R v2, the original IP source
address and TCP/UDP source port numbers are written into the destination
fields of the packet (since it is now moving in the opposite direction), the
checksums are recomputed, and the packet is delivered to its true destination.
This is because SUA keeps a table of the IP addresses and port numbers of
the local systems currently using it.
10. What is the difference between SUA and Full Feature NAT?
When you edit NAT in Web Configurator, Advanced Setup, Network -> NAT
-> General, there will be three options for you:
-> General, there will be three options for you:
z
Inactive NAT
z
SUA Only
z
Full Feature
SUA (Single User Account) in previous ZyNOS versions is a NAT set with 2
rules: Many-to-One and Server. With SUA, 'visible' servers had to be mapped
to different ports, since the servers share only one global IP.
rules: Many-to-One and Server. With SUA, 'visible' servers had to be mapped
to different ports, since the servers share only one global IP.
The P-791R v2 now has Full Feature NAT which supports five types of IP/Port
mapping: One to One, Many to One, Many to Many Overload, Many to Many
No Overload and Server. You can make special application when you select
Full Feature NAT. For example: With multiple global IP addresses, multiple
severs using the same port (e.g., FTP servers using port 21/20) are allowed on
the LAN for outside access.
mapping: One to One, Many to One, Many to Many Overload, Many to Many
No Overload and Server. You can make special application when you select
Full Feature NAT. For example: With multiple global IP addresses, multiple
severs using the same port (e.g., FTP servers using port 21/20) are allowed on
the LAN for outside access.
You can edit Full Feature NAT in Network->NAT->Address Mapping
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