Configuring a Vocera SIP Telephony Gateway with Dual NICs

If your Vocera Voice Server and the PBX that Vocera SIP Telephony Gateway connects to are located on different subnets, your Vocera SIP Telephony Gateway requires dual network interface cards (NICs) to connect to both subnets. Additionally, you must configure the Vocera SIP Telephony Gateway so that it uses the correct IP address for SIP and RTP signaling. By default, the primary NIC address is used for SIP and RTP signaling.

The following figure shows a VSTG connecting to a Vocera Voice Server and an IP PBX on different VLANs.

Figure 1. VSTG with dual NICs

Table 1. SIP and RTP interface properties
Property	Description
VTGSIPInterfaceAddress	If Vocera SIP Telephony Gateway should use a different IP address than the primary NIC address for SIP signaling, specify the IP address in dotted-decimal notation (for example, 192.168.15.10).
VTGRTPInterfaceAddress	If Vocera SIP Telephony Gateway should use a different IP address than the primary NIC address for RTP signaling, specify the IP address in dotted-decimal notation (for example, 192.168.15.10).

Note: By default, both the VTGSIPInterfaceAddress and VTGRTPInterfaceAddress properties are preceded by pound signs (#) in the vgwproperties.txt file. The pound signs denote comments, which means these properties are ignored by Vocera SIP Telephony Gateway. If you want to set these properties, make sure you remove the pound signs that precede the property names.