Multicast and Smartphones

Vocera Collaboration Suite clients that run on iOS and Android devices support multicast transmissions for broadcast and push-to-talk conferences.

The Vocera Client Gateway uses IGMPv2 by default for multicast traffic. However, to enable multicast transmissions on the Vocera Client Gateway, you must set the VGWSupportMulticast property to TRUE. Otherwise, Vocera Client Gateway performs multicast to unicast translation for Vocera Collaboration Suite devices. For more information, refer to Vocera Voice Server Telephony Configuration Guide.

To disable multicast transmissions on the Vocera Client Gateway, use the following guidelines to ensure that multicast traffic is routed properly from badges and the Vocera Voice Server to the Vocera Client Gateway:

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

If multicast traffic is not routed properly, smartphone users will not receive audio packets from badge users during broadcasts or instant conferences (push-to-talk sessions.)

To test broadcasts on a smartphone, perform the following steps:

Log into the administration console as a Vocera system administrator.
Create two test users, UserOne and UserTwo.
Create an administrative group called Broadcast if one does not already exist.
Grant the Broadcast group the Initiate Broadcasts permission.
Create another group called Test.
Add UserOne and UserTwo to the Broadcast group.
Add UserOne and UserTwo to the Test group.
Log into a badge as UserOne.
Log into a smartphone with VCS as UserTwo.
On the badge, press the Call button and say, Broadcast to Test. Proceed to say a test broadcast, for example, Testing 1, 2, 3, 4.
On the receiving end of the broadcast, the smartphone should play a chime and then you should hear the broadcast.
If you hear the chime but no audio from the broadcast, multicast packets are not being routed properly. Check the IP multicast settings on the Layer 3 switches that the Vocera Client Gateway subnet crosses.
Test a broadcast from a smartphone to a badge.
On the smartphone, press the call button and say, Broadcast to Test. Proceed to say a test broadcast as you did earlier on the badge.

The badge plays a chime, and then you hear the broadcast.
Note: If you hear the chime but no audio from the broadcast, multicast packets are not being routed properly.