We have two sites.
Site 1 (main site):
Controllers reside at site 1 on the core 6500.
When the broadcast initiator performs a broadcast, users with badges in the broadcast group can hear the chime and audio.
No controllers exists. Core is fiber connected to site 1.
When the broadcast initiator performs a broadcast, users with badges in the broadcast group can hear the chime and no audio.
I had a user at site 2 test a broadcast to users at site 2 and a badge I had at site 1. The users at site 2 could only hear the chime, but no audio. On the other hand, I could hear both the chime and the audio.
IP multicast routing is set up on the routers at each site.
PIM (Protocol Independent Multicast) is enabled on the layer 3 interface directly connect to the controllers at site 1.
VLAN IGMP Snooping is disabled on the Vocera VLAN that is directly connected to each WLC.
See more information for multicast here: http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a0080766d54.shtml
We followed Vocera's best practices here:
Any insight in resolving this issue is much appreciated.