Multicast Traffic

Multicasting is a method of sending messages or data to many clients at the same time using IP multicast group addresses. Multicasting is more efficient than unicasting.

A badge can send one multicast packet to many receivers instead of sending one copy of the unicast packet to each receiver. Vocera uses multicast transmissions to provide broadcasts and Push-to-Talk (PTT) conferences. Vocera multicast features can be configured to cross subnet boundaries.

Vocera broadcast and instant conference push-to-talk feature use multicast to forward IP datagrams to a multicast group within a single subnet, for urgent broadcast command, VMI broadcast, and broadcast from a phone. If your network uses Internet Group Management Protocol (IGMP) to manage multicast traffic between IP hosts across an IP subnet boundary, you may configure all badges to support IGMP broadcasts.

By default, B3000 use IGMP version 2 and B3000n uses IGMP version 3. You need to adjust the settings to choose IGMP version 2 if you have older switches that do not support IGMPv3. Ensure that you enable IGMPv2 on all intermediate routers or other Layer 3 network devices on each subnet used by Vocera devices. For more information on IGMP, refer to Layer 3 IGMP.