SIP User's Manual  548  Document #: LTRT-12804 
  Mediant 800 MSBG 
 
8.4.10.1.2 Step 2: Assign VoIP Traffic to WAN Interface 
Once you have defined the WAN IP address (see ''Assigning a WAN IP Address'' on page 
29) fo
r the data-routing interface, you then need to associate it with VoIP traffic (i.e., SIP 
signaling and media / RTP interfaces). The available WAN interfaces depend on the 
hardware configuration (i.e., Ethernet, T1, or SHDSL) and/or whether VLANs are defined 
for the WAN interface. If VLANs are defined, then you can select the WAN VLAN on which 
you want to run the SIP signaling and media interfaces. Once this association is set, VoIP 
traffic is sent on the WAN and incoming traffic is identified as coming from the WAN. The 
device also automatically configures the required port forwarding and static NAT rules. 
 
 
Note:  If you do not assign the WAN interface to SIP and media interfaces, then the 
WAN interface may not be used for VoIP traffic. In such scenarios, the VoIP 
traffic can be sent and received within the LAN, or sent to the WAN via a 
third-party LAN router. If a third-party router is used as the interface to the 
WAN, then you need to define NAT rules (using the NATTranslation 
parameter) to translate the VoIP LAN IP addresses (defined in the Multiple 
Interface table and associated with SIP and media interfaces) into global, 
public IP addresses. 
 
¾  To assign a WAN interface to VoIP traffic: 
1.  Select the WAN interface: 
a.  Open the 'Multiple Interface Table' page (Configuration tab > VoIP menu > 
Network submenu > IP Settings). 
Figure  8-60: Selecting WAN Interface for VoIP Traffic 
 
b.  From the 'WAN Interface Name' drop-down list, select the WAN interface for VoIP 
traffic. 
c.  Click Done, and then reset the device for your setting to take effect. 
2.  Assign the selected WAN interface to SIP signaling and RTP (media) interfaces. This 
is done in the SIP Interface and SIP Media Realm tables respectively (whereby the 
WAN interface is denoted as "WAN"), as described in ''Step 4: Configure Multiple SIP 
and RTP Interfaces'' on page 550. 
 
8.4.10.1.3 Step 3: Enable the SBC Application 
The procedure below describes how to enable the SBC application. Once enabled, the 
SBC-specific parameters/pages become available in the Web interface.