Troubleshooting guide

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Cisco PGW 2200 Softswitch Release 9.8 Operations, Maintenance, and Troubleshooting Guide
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Chapter 1 Cisco PGW 2200 Softswitch Platform Overview
Cisco PGW 2200 Softswitch Software Architecture
Execution Environment Process Shell
The execution environment process shell is an operating system shell on the Cisco PGW 2200 Softswitch
that enables it to access lower-level functionality. The low-level functions hold together the I/O, element
management, and call engine subsystems on the Cisco PGW 2200 Softswitch. The execution
environment infrastructure provides the following functions to Cisco PGW 2200 Softswitch processes:
• Operating system interface—Sun Solaris operating system command processor.
• Process management—Performs startup order, shutdown order, and monitoring of processes. Also
performs software upgrade compatibility checking with minimal service interruption.
• Alarm management—Allows processes to register, set, and clear alarms, which are then presented
to the AMS for further processing.
• Log management—Allows Cisco PGW 2200 Softswitch processes to log messages to locally
persistent data files. Message codes (instead of strings) minimize the overhead of interprocess
transport of long buffers. Log files reveal the process type that generates the log, and the logging
level (severity).
• Measurement management—Allows processes to adjust counters or other metrics, which are
subsequently presented to the AMS for Alarm and Measurement Report processing.
• Command management—Interface that can be used by any active processes or by an EMS interface,
such as MML or SNMP agents, to exchange commands or responses.
• Configuration management—Notifies processes and gets responses when configuration data
changes. Handles reconfiguration management when multiple processes are affected by changes.
• Access control—Allows only authorized processes to access certain services or other processes.
• Interprocess communication (IPC)—Allows processes to exchange messages.
• Event Processing Service—XEProcShell facility allows applications to register, deregister, and
exchange events (messages) through IPC. This service is critical to efficient real-time CPU usage
and overall system performance.
• Timers—Allow processes to set, clear, or monitor timers. Provide timeouts to processes.
Call Engine Process
The call engine is a process designed to provide the means and resources for call processing to take
place. The call engine involves the following components:
• Resource manager—Performs the following functions:
– Tracks all bearer resources used. Proxies and tracks the bearer resources in the trunking
gateways within the Cisco PGW 2200 Softswitch service area.
– Services all requests for allocation or deallocation of bearer resources from call instances.
– Executes bearer allocation algorithms (circuit selection).
– Manages echo cancellation for a call.
– Performs continuity tests.
– Checkpoints bearer states and modes to the standby Cisco PGW 2200 Softswitch to guarantee
that the bearer channel is not lost during a manual or automatic switchover.