Software Reliability; Core Security; Figure 13. Security Interfaces - Aastra Clearspan Product Overview

network. Once the endpoint has connected to Clearspan, the rest of the network discovers which
Application Server is hosting the associated user's services through the Network Server. This
forces all subsequent user transactions to be sent to the hosting Application Server. This solution is
ideal for deploying geographic network solutions.
2.2.5

Software Reliability

A system controller manages each Clearspan server by monitoring the health of the server and
keeping its processes up and running. Alarms are generated in the event of a software failure.
Internally, each process contains a "watch-dog" thread to keep all subsystems alive and functioning
and to minimize service interruptions. This means a software failure results in a maximum of one
lost call. Call processing session audits are performed by the Application Server to tear down any
hung sessions caused by malfunctioning endpoints in the network.
2.3

Core Security

Platform security is of prime importance within the Clearspan architecture. The following figure
highlights the fact that only a few interfaces are exposed to the untrusted network: The XSP server
and the SIP Session Manager (SSM), which is also known as a Session Border Controller (SBC).
Clearspan® Product Overview R19
2014 Clearspan® is a Registered Trademark of Aastra Technologies Ltd.

Figure 13. Security Interfaces.

Aastra – 2740-007
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