AudioCodes Mediant 3000, User Manual

Page: 141 / 872

Version 6.6 141 Mediant 3000
User's Manual 11. Network
Parameter Description
Source Interface
Name
[NATTranslation_So
urceIPInterfaceNam
e]
Defines the name of the IP interface, as appears in the Multiple Interface
table.
Note: If the Multiple Interface table is not configured, the default Source IP
Interface Name is "All". This represents the single IP interface for OAMP,
Control, and Media (defined by the LocalOAMIPAddress,
LocalOAMSubnetMask, and LocalOAMDefaultGW parameters).
Target IP Address
[NATTranslation_Tar
getIPAddress]
Defines the global IP address. This address is set in the SIP Via and
Contact headers as well as in the o= and c= SDP fields.
Source Start Port
[NATTranslation_So
urceStartPort]
Defines the optional starting port range (1-65536) of the IP interface, used
as matching criteria for this NAT rule. If not configured, the match is done
on the entire port range. Only IP addresses and ports of matched source
ports will be replaced.
Source End Port
[NATTranslation_So
urceEndPort]
Defines the optional ending port range (1-65536) of the IP interface, used
as matching criteria for this NAT rule. If not configured, the match is done
on the entire port range. Only IP addresses and ports of matched source
ports will be replaced.
Target Start Port
[NATTranslation_Tar
getStartPort]
Defines the optional, starting port range (1-65536) of the global address. If
not configured, the ports are not replaced. Matching source ports are
replaced with the target ports. This address is set in the SIP Via and
Contact headers, as well as in the o= and c= SDP fields.
Target End Port
[NATTranslation_Tar
getEndPort]
Defines the optional, ending port range (1-65536) of the global address. If
not configured, the ports are not replaced. Matching source ports are
replaced with the target ports. This address is set in the SIP Via and
Contact headers, as well as in the o= and c= SDP fields.
11.9.2 Remote UA behind NAT
If the remote User Agent with which the device needs to communicate with is located
behind NAT, the device can resolve the problem of activating the RTP/RTCP/T.38 streams
to an invalid IP address / UDP port.
To resolve this NAT traversal issue, the device offers the following features:

First Incoming Packet Mechanism - see 'First Incoming Packet Mechanism' on page
142

RTP No-Op packets according to the avt-rtp-noop draft - see 'No-Op Packets' on page
142
The figure below illustrates a typical network architecture where the remote UA is located
behind NAT:
Figure 11-14: Remote UA behind NAT