Cannot receive calls

This is related to the IP Handset (IP Centrex), or the Gateway Device (IBL, PRI) ability to register to VoiceMailTel network. There are a few possible causes:

1. Power Outages
2. Loss of Internet Connectivity
3. Router / Firewall security options are blocking VOIP traffic.

Note: Calls should still route to Auto Attendent and/or VM. Customer can also choose emergency routing options, i.e. route to cellular phones.