Software Reliability - Huawei U-SYS MRS6100 Technical Manual

Technical Manual
U-SYS MRS6100 Media Resource Server
brought into service immediately. The standby one replaces the active one to control
the running and operation of the modules against service interruption of the system.
III. Board-level Hot Standby Mode
The board-level hot backup method is frequently used in communication products to
improve the reliability of the system. This method usually adopts the active/standby
work mode and is mainly applicable to service processing, device management and
resource management.
IV. Mutual-aid working mode
Mutual-aid work is also known as load-sharing. With the mutual-aid work mode, two or
more boards share the related functions during the normal working. Once one of the
boards becomes faulty, other boards take over the tasks imposed on the faulty one on
the premise that certain performance parameters such as call loss are guaranteed.

10.2.2 Software Reliability

The MRS6100 software adopts a hierarchical modularized architecture with
protective performance, error tolerance capability and fault monitoring function.
I. Protection Performance
From requirement analysis, system design to software test, all stages of the
development of MRS6100 strictly follow the Capability Maturity Model (CMM)
procedures. Code walk-through, review, inspection, unit test, system test and other
useful quality assurance measures taken during MRS6100 development greatly
improve the reliability of the software.
II. Error-tolerance Capability
By means of key software resource timing detection, real-time task monitoring,
storage protection and data check, MRS6100 effectively prevents minor software
faults from imposing bad effects on the whole system. It greatly improves the error
tolerance capability of the system.
III. Fault detection and handling
The MRS6100 can automatically detect and diagnose both software and hardware
faults. The faulty components can be automatically switched, restarted and reloaded
to avoid service interruption.
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Chapter 10 Reliability Design