What is the default TCP port for SIP OAuth mode in Cisco UCM?

Refer to the exhibit. A collaboration engineer adds a redundant NTP server to an existing Cisco Collaboration solution On the Cisco UCM OS Administration page, the new NTP server shows as " Not Accessible " Which action resolves this issue?
Which issue cause slips on a PRI?
What must be modified or the administration page In Cisco UCM when designing layered security?