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10.5
The DMZ Screen
In addition to the servers for specified services, NAT supports a default server IP address. A default
server receives packets from ports that are not specified in the
NAT Port Forwarding Setup
screen.
Figure 89
Network Setting > NAT > DMZ
The following table describes the fields in this screen.
10.6
The ALG Screen
Some NAT routers may include a SIP Application Layer Gateway (ALG). A SIP ALG allows SIP calls
to pass through NAT by examining and translating IP addresses embedded in the data stream.
When the Device registers with the SIP register server, the SIP ALG translates the Device’s private
IP address inside the SIP data stream to a public IP address. You do not need to use STUN or an
outbound proxy if your Device is behind a SIP ALG.
Use this screen to enable and disable the NAT and SIP (VoIP) ALG in the Device. To access this
screen, click
Network Setting > NAT > ALG
.
Figure 90
Network Setting > NAT > ALG
Table 62
Network Setting > NAT > DMZ
LABEL
DESCRIPTION
Default Server
Address
Enter the IP address of the default server which receives packets from ports that are not
specified in the
NAT Port Forwarding
screen.
Note: If you do not assign a
Default Server Address
, the Device discards all packets
received for ports that are not specified in the
NAT Port Forwarding
screen.
Apply
Click
Apply
to save your changes.
Cancel
Click
Cancel
to restore your previously saved settings.
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The following table describes the fields in this screen.
10.7
The Address Mapping Screen
Ordering your rules is important because the Device applies the rules in the order that you specify.
When a rule matches the current packet, the Device takes the corresponding action and the
remaining rules are ignored.
Click
Network Setting > NAT > Address Mapping
to display the following screen.
Figure 91
Network Setting > NAT > Address Mapping
The following table describes the fields in this screen.
Table 63
Network Setting > NAT > ALG
LABEL
DESCRIPTION
NAT ALG
Enable this to make sure applications such as FTP and file transfer in IM applications work
correctly with port-forwarding and address-mapping rules.
SIP ALG
Enable this to make sure SIP (VoIP) works correctly with port-forwarding and address-
mapping rules.
RTSP ALG
Enable this to have the Device detect RTSP traffic and help build RTSP sessions through its
NAT. The Real Time Streaming (media control) Protocol (RTSP) is a remote control for
multimedia on the Internet.
Apply
Click
Apply
to save your changes.
Cancel
Click
Cancel
to restore your previously saved settings.
Table 64
Network Setting > NAT > Address Mapping
LABEL
DESCRIPTION
Add new rule
Click this to create a new rule.
Set
This is the index number of the address mapping set.
Local Start IP
This is the starting Inside Local IP Address (ILA).
Local End IP
This is the ending Inside Local IP Address (ILA). If the rule is for all local IP addresses, then
this field displays 0.0.0.0 as the Local Start IP address and 255.255.255.255 as the Local
End IP address. This field is blank for
One-to-One
mapping types.
Global Start IP
This is the starting Inside Global IP Address (IGA). Enter 0.0.0.0 here if you have a dynamic
IP address from your ISP. You can only do this for the
Many-to-One
mapping type.
Global End IP
This is the ending Inside Global IP Address (IGA). This field is blank for
One-to-One
and
Many-to-One
mapping types.
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10.7.1
Add/Edit Address Mapping Rule
To add or edit an address mapping rule, click
Add new rule
or the rule’s edit icon in the
Address
Mapping
screen to display the screen shown next.
Figure 92
Address Mapping: Add/Edit
The following table describes the fields in this screen.
Type
This is the address mapping type.
One-to-One
: This mode maps one local IP address to one global IP address. Note that port
numbers do not change for the One-to-one NAT mapping type.
Many-to-One
: This mode maps multiple local IP addresses to one global IP address. This is
equivalent to SUA (i.e., PAT, port address translation), the Device's Single User Account
feature that previous routers supported only.
Many-to-Many
: This mode maps multiple local IP addresses to shared global IP addresses.
Modify
Click the
Edit
icon to go to the screen where you can edit the address mapping rule.
Click the
Delete
icon to delete an existing address mapping rule. Note that subsequent
address mapping rules move up by one when you take this action.
Table 64
Network Setting > NAT > Address Mapping (continued)
LABEL
DESCRIPTION
Table 65
Address Mapping: Add/Edit
LABEL
DESCRIPTION
Type
Choose the IP/port mapping type from one of the following.
One-to-One
: This mode maps one local IP address to one global IP address. Note that port
numbers do not change for the One-to-one NAT mapping type.
Many-to-One
: This mode maps multiple local IP addresses to one global IP address. This is
equivalent to SUA (i.e., PAT, port address translation), the Device's Single User Account
feature that previous routers supported only.
Many-to-Many
: This mode maps multiple local IP addresses to shared global IP addresses.
Local Start IP
Enter the starting Inside Local IP Address (ILA).
Local End IP
Enter the ending Inside Local IP Address (ILA). If the rule is for all local IP addresses, then
this field displays 0.0.0.0 as the Local Start IP address and 255.255.255.255 as the Local
End IP address. This field is blank for
One-to-One
mapping types.
Global Start IP
Enter the starting Inside Global IP Address (IGA). Enter 0.0.0.0 here if you have a dynamic
IP address from your ISP. You can only do this for the
Many-to-One
mapping type.
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10.8
The Address Mapping Screen
Ordering your rules is important because the Device applies the rules in the order that you specify.
When a rule matches the current packet, the Device takes the corresponding action and the
remaining rules are ignored.
Click
Network Setting > NAT > Address Mapping
to display the following screen.
Figure 93
Network Setting > NAT > Address Mapping
The following table describes the fields in this screen.
Global End IP
Enter the ending Inside Global IP Address (IGA). This field is blank for
One-to-One
and
Many-to-One
mapping types.
Set
Select the number of the mapping set for which you want to configure.
OK
Click
OK
to save your changes.
Cancel
Click
Cancel
to exit this screen without saving.
Table 65
Address Mapping: Add/Edit (continued)
LABEL
DESCRIPTION
Table 66
Network Setting > NAT > Address Mapping
LABEL
DESCRIPTION
Add new rule
Click this to create a new rule.
Set
This is the index number of the address mapping set.
Local Start IP
This is the starting Inside Local IP Address (ILA).
Local End IP
This is the ending Inside Local IP Address (ILA). If the rule is for all local IP addresses, then
this field displays 0.0.0.0 as the Local Start IP address and 255.255.255.255 as the Local
End IP address. This field is blank for
One-to-One
mapping types.
Global Start IP
This is the starting Inside Global IP Address (IGA). Enter 0.0.0.0 here if you have a dynamic
IP address from your ISP. You can only do this for the
Many-to-One
mapping type.
Global End IP
This is the ending Inside Global IP Address (IGA). This field is blank for
One-to-One
and
Many-to-One
mapping types.
Type
This is the address mapping type.
One-to-One
: This mode maps one local IP address to one global IP address. Note that port
numbers do not change for the One-to-one NAT mapping type.
Many-to-One
: This mode maps multiple local IP addresses to one global IP address. This is
equivalent to SUA (i.e., PAT, port address translation), the Device's Single User Account
feature that previous routers supported only.
Many-to-Many
: This mode maps multiple local IP addresses to shared global IP addresses.
Modify
Click the
Edit
icon to go to the screen where you can edit the address mapping rule.
Click the
Delete
icon to delete an existing address mapping rule. Note that subsequent
address mapping rules move up by one when you take this action.
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10.9
The Sessions Screen
Use this screen to limit the number of concurrent NAT sessions a client can use. Click
Network
Setting > NAT > Sessions
to display the following screen.
Figure 94
Network Setting > NAT > Sessions
The following table describes the fields in this screen.
10.10
Technical Reference
This part contains more information regarding NAT.
10.10.1
NAT Definitions
Inside/outside denotes where a host is located relative to the Device, for example, the computers
of your subscribers are the inside hosts, while the web servers on the Internet are the outside
hosts.
Global/local denotes the IP address of a host in a packet as the packet traverses a router, for
example, the local address refers to the IP address of a host when the packet is in the local
network, while the global address refers to the IP address of the host when the same packet is
traveling in the WAN side.
Table 67
Network Setting > NAT > Sessions
LABEL
DESCRIPTION
WAX NAT
Session Per
Host
Use this field to set a limit to the number of concurrent NAT sessions each client host can
have.
If only a few clients use peer to peer applications, you can raise this number to improve
their performance. With heavy peer-to-peer application use, lower this number to ensure no
single client uses too many of the available NAT sessions.
Apply
Click this to save your changes on this screen.
Cancel
Click this to exit this screen without saving any changes.

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