We've have a new VoIP implementation with 24 x 7921 Cisco WiFi handests. The wifi controller is a Symbol RFS 6000. The phones register with a call manager on a remote site across a MPLS WAN link. Voice data is on it's own subnet. QoS is configured on LAN and WAN. Phones get their IPs from DHCP
The issue we are seeing is an increasing ping time to the phone. Starts at approx 5ms, graually increases to approx 1500ms, then some packet drops. Then it starts over again, 5ms increaing to 1500 ms.
Configured phones with static IPs but pings keep increasing.
Ping times to Controller from switch are steady.
Ping times to other wifi devices on othe WLANs are steady.
Phones have been registered with another call manager but pings still increase.