VOIP Dropped packets, voice disruption?

What QoS configuration are you running on the switches?  I don't know if Cisco switches will automatically recognize the devices, but if the devices are properly marking packets, the switch can be set to trust those markings.

Not running QOS on most switches.

Using  separate VLANs  for data & phone.

Just because you have separate VLANs set for voice, it doesn't mean that VLAN traffic will get priority. You need to setup QoS to eliminate (minimize) the issues you are experiencing by prioritizing the voice traffic through the switches...

Testing for lost packets, PING, was done after hours.  No data should have interfered.  Any more ideas?

OK, I think maybe I didn't understand your original post... when you said "PINGed phones to detect the lost packets", are you actually loosing packets or was that just diagnostic? Your last post didn't specifically say you were loosing packets. If you actually have packet loss, that's most likely not a QoS issue, escpecially if it after hours, no traffic....

Yes, we discovered toruble with some phones by PINGing.  Booting the phone seems to resolve the PING problem temporarily.  The user experience is voice calls periodically "breaking up" among other lesser issues..

Is this is separate network for the voice systems? Are there any other devices in the network that your loosing packets to? Test other devices (data devices too if it's a combinded network)....

Is it only certain phones? If it is only certain phones, swap those phones with others that 'work' and see if the problem follows the phone...