Running 8.6 on uc540s and uc560. Using system-park application under telephony-service. Been finding more and more that park slots are getting stuck at various installation. Cisco small business techs can't identify the issue. Their original recommendation was to upgrade to 8.6 and put the park slots at the end of the ephone-dns. Still occurs.
Basically, client finds they can't park a call. Callers being put into park are disconnected. Park slot not lit up on phone as occupied. Calling the park slot results in a busy signal. Once the the first park slot is ghosted, all parking function stops. Probably cause phone system tries to park in first slot, but it's ghosted/hung.
Only solution in each case by Cisco small business support for the various clients when they are remoted in is to reboot the phone system. Happens once every week or two for the regular clients that park calls often.
Example - 601 is the first park slot.
UC560#show call active voice com UC560#
<callID> A/O FAX T<sec> Codec type Peer Address IP R<ip>:<udp>
Total call-legs: 1
9439 ORG T7157 g711ulaw TELE P601
UC560#show call active voice com