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About the Coral Sentinel Pro
Sentinel Pro Installation Procedure and Reference Manual
- for Coral IPx / FlexiCom
The Need for Sentinel
Pro
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The Need for Sentinel Pro
Indirect Connection Caused by Firewalls
Firewalls do not allow direct connection from the outside world to the internal LAN,
as signalling and media traffic must first travel through the firewall.
The Coral Sentinel Pro acts as a transmission point, enabling all signalling and media
traffic to be routed to and from the remote IP endpoints.
Unique IP Sockets Assigned by NAT Devices
NAT devices assign a unique IP socket to every RTP session upon call setup. Coral (or
any other call agent or registrar) is unable to set up a session without knowing which
port the NAT will assign.
To address this, the Sentinel Pro acts as a meeting point. The IP endpoints direct their
RTP streams towards the Sentinel Pro, which detects the source IP socket, adjusting
the destination of the RTP streams it transmits accordingly.
Dedicated Ports for VoIP Signaling
Coral (as any call agent or registrar) assigns specific ports for the handling of VoIP
signaling data, as follows:
MGCP: 2427 or 2727
The IP sockets of incoming sessions have to be adjusted to contain the relevant port
number.
The Sentinel Pro acts like multiple virtual IP endpoints that receive the calls, redefine
the incoming IP sockets, and route them to the Coral unit through the relevant
signaling port.