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Cisco H.323 Signaling Interface User Guide
OL-4806-01 Rev. A14
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Cisco H.323 Signaling Interface Overview
Introduction
This chapter provides an overview of the Cisco H.323 Signaling Interface (HSI) system and subsystems
and contains the following sections:
•
Cisco HSI Overview, page 1-1
•
Cisco HSI System Description, page 1-2
•
Operational Environment, page 1-4
•
Cisco HSI Recovery, page 1-5
•
Cisco HSI System Limitations, page 1-5
Cisco HSI Overview
The Cisco HSI adds an H.323 interface to the Cisco Public Switched Telephone Network (PSTN)
Gateway (PGW 2200). This interface allows calls to be established between the PSTN and an H.323
network (see
Figure 1-1
).
The Cisco HSI provides the following services:
•
Translation of signaling protocols for establishing, controlling, and releasing calls
•
Administration of network parameters and protocol capabilities
•
System and call-related statistics
•
Fault reporting
•
Overload management
•
Event logging
•
Simple Network Management Protocol (SNMP) interface
The Cisco HSI does not operate in an active/standby configuration and, therefore, does not provide the
same level of redundancy as the PGW 2200, which is configured as active/standby. We therefore
recommend that you use enough HSI nodes to support the number of simultaneous calls plus one. This
ensures (Trunk Group Caveats dependant) that, if one HSI fails, the calls are still adequately supported
by the remaining active HSIs.
