Multicast and Vocera Messaging Interface Broadcasts

Vocera Messaging Interface (VMI) can be configured to use IP multicast to broadcast one-way, urgent VMI messages without responses from the server to all recipient devices. VMI thus uses only one speech port for the broadcast.

To support broadcast of one-way, urgent VMI messages and to ensure that multicast traffic is routed correctly from the Vocera Voice Server to Vocera devices, use the following guidelines:

Enable multicast routing support on the Layer 3 switches that the Vocera Voice Server subnet crosses.
Check the IP multicast settings you enabled on the subnet that the Vocera devices use.
Set the Broadcast Uses IGMP property to TRUE on all Vocera badges.
Ensure that IGMPv2 is enabled on all intermediate routers or other Layer 3 network devices on each subnet used by Vocera devices. With IGMP enabled, VMI broadcasts can cross subnet boundaries. For more information, refer to Layer 3 IGMP.

If multicast traffic is not routed properly, you will not receive audio packets during the broadcast of an urgent VMI message. For details on how to enable VMI broadcasts, refer to the Vocera Messaging Interface Guide.

To test the broadcast of a one-way urgent VMI message, perform the following steps:

Enable broadcast of urgent VMI messages by modifying the properties.txt file on the Vocera Voice Server. For more information, refer to Vocera Messaging Interface Guide.
Log into the Administration Console as a Vocera system administrator.
Create a group called Test.
Create two test users, UserOne and UserTwo.
Add UserOne and UserTwo to the Test group.
Log into one badge as UserOne and another badge as UserTwo.
Run the vmitest.exe sample application that is included with VMI.
The application opens in a command prompt window. For more information on vmitest, refer to Vocera Messaging Interface Guide.
In the vmitest application, type o to open a gateway. Enter the client ID and then the Vocera Voice Server IP address.
When the connection is opened Accepted message is displayed.

Type m to send a message. Enter the following parameter values:

Parameter	Value
Message ID	Specifies the message ID. A unique number.
Login ID	Specifies the login ID. For example: `Test`
Message Text	Specifies any message long enough to test the broadcast. For example: `Testing 1, 2, 3, 4`
Priority	Specifies the priority vales. For example: `urgent`
Call-back Phone No	Specifies the call-back phone number.
Response Choices	Specifies the response choice.
WAV File Root Names	Specifies the root name of the WAV file.

On the receiving end of the broadcast, the badges should play the alert tone for urgent messages. By default, two clunks are played.
Broadcast being played on both badges.
If you hear the alert tone but no audio from the broadcast, that means that multicast packets are not routed properly. Check the IP multicast settings on the Layer 3 switches that the Vocera Voice Server subnet crosses.