Version 7.2  155  Mediant 1000B Gateway & E-SBC 
 
User's Manual   12. Network 
12.7.1.2  Configuring NAT Translation per IP Interface 
The NAT Translation table lets you configure up to 32 network address translation (NAT) 
rules for translating source IP addresses per VoIP interface (SIP control and RTP media 
traffic) into NAT IP addresses (global - public) when the device is located behind NAT. The 
device's NAT traversal mechanism replaces the source IP address of SIP messages sent 
from a specified VoIP interface to a public IP address. This allows, for example, the 
separation of VoIP traffic between different ITSPs and topology hiding of internal IP 
addresses from the “public” network. Each IP network interface, configured in the IP 
Interfaces table can be associated with a NAT rule, translating the source IP address and 
port of the outgoing packet into the NAT address (IP address and port range).   
 
The following procedure describes how to configure NAT translation rules through the Web 
interface. You can also configure it through ini file (NATTranslation)  or CLI (configure 
network > nat-translation). 
  To configure NAT translation rules: 
1.  Open the NAT Translation table (Setup  menu > IP Network  tab > Core Entities 
folder > NAT Translation). 
2.  Click New; the following dialog box appears: 
Figure  12-7: NAT Translation Table - Dialog Box 
 
3.  Configure a NAT translation rule according to the parameters described in the table 
below. 
4.  Click Apply, and then save your settings to flash memory. 
Table  12-15: NAT Translation Table Parameter Descriptions 
Parameter  Description 
Source 
Index 
index 
[NATTranslation_Index] 
Defines an index number for the new table row.  
Note: Each row must be configured with a unique index. 
Source Interface 
src-interface-name 
[NATTranslation_SrcIPInterfaceName]
Assigns an IP network interface (configured in the IP 
Interfaces table) to the rule. Outgoing packets sent from the 
specified network interface are NAT'ed. 
By default, no value is defined.  
To configure IP network interfaces, see ''Configuring IP 
Network Interfaces'' on page 142.