The CyberData SIP Paging Adapter is a VoIP endpoint that interfaces analog paging systems with SIP and Multicast-based audio sources. The SPA (SIP Paging Adapter) can be configured to support two separate SIP extensions. SIP extension one passes audio through to the analog output spoken from the caller’s handset. When called, SIP extension two plays a bell audio that can be used as a night ringer when configured in a night ring group. The SPA supports up to 9 user-loadable messages that can be played by a DTMF command. The SPA supports a line-In input for playing MOH.

Other available facets are like:

• Two SIP extensions (Note: One of these extensions is a dedicated "night ringer," which is not capable of answering a call, and will only play a stored message while the call is ringing.)
• Voice prompt pass code and page control
• DTMF and programmatic controlled Relay

Apart from these, you can find manifold other smarter features and we at Cohesive Technologies give you the best options.