I have CUCM-6.0.1. After I am registering my third party SIP device, CUCM is sending the immediate VM NOTIFY. Following are my concerns over the issue;
1. Why CUCM is sending NOTIFY without my device sending the SUBSCRIBE request?
2. Is there any way to block the server from sending the NOTIFY?
2. Also, when the third party device sends SUBSCRIBE request, CUCM is sending back "489-Event Package Not Supported". What could be the reason? Is CUCM is not supporting SUBSCRIBE-NOTIFY based MWI subscription?