Introduction:
why chorus?
The ChorusOS™ operating system is a highly
scalable and
reliable embedded operating system, that has established itself
among top telecom suppliers. The ChorusOS operating system is
used in public switches and PBXs, as well as within access
networks, cross-connect switches, voice-mail systems, cellular
base stations, web-phones and cellular telephones.
An open and flexible solution, the ChorusOS operating system also
allows developers to rapidly respond to customer needs and
market conditions by quickly and cost-effectively creating and
deploying new services and mission-critical applications. With
enhanced networking features, the ChorusOS operating system
seamlessly supports third-party protocol stacks, legacy
applications, real-time and Java technology-based applications
simultaneously on a single hardware platform.
High-End Real-Time OS Base
A high-end, real-time operating system, ChorusOS™ software
brings the following features:
Component-based architecture for
super-configurability
The ChorusOS operating system uses a highly-flexible,
component-based architecture that allows different services
to be configured into the runtime instance of the operating
system. This allows the runtime instance of the ChorusOS
operating system to be finely tuned, according to the
underlying hardware platform, the memory footprint
requirements and the application features.
Mission-critical quality
From its origin, the operating system has been jointly defined
and created in collaboration with leading network equipment
providers, in order to allow it to comply fully with their
requirements for the real-time embedded elements of
network equipment. The ChorusOS operating system has
already been used over the past six years in mission-critical
telecom products dedicated to PSTN and IP switching, for
which high performance was a key requirement.
Exceptional scaleability
The component-based design of the ChorusOS operating
system allows a very high degree of scaleability. An
operating system based on only the micro core executive
typically requires only about 10 Kilobytes of memory to run.
Additional components can be added, to create a tailor
made instance, to the level of the resources available.
Multiple OS personalities and APIs
Multiple operating system personalities and APIs can be run
simultaneously on a common hardware platform using the
ChorusOS operating system, in such a way that diverse
applications can communicate transparently. This feature
allows quick integration of existing applications on top of the
ChorusOS microkernel. The system can then be extended by
adding new applications that run over standard APIs, to
create powerful combinations of legacy applications, real-
time POSIX applications, and Java(tm) applications.
Support for Java Dynamic Management Kit™ (Java
DMK) and Jini™ Connection Technology
The support for multiple OS personalities provided by Sun's
embedded telecom platform has enabled extension of the
system implementation from the ChorusOS operating
system's real-time oriented POSIX sub-system, to include
key Java technologies valuable in network equipment, such
as the Java DMK framework. The inclusion of Java DMK
brings OAM&P capabilities to the platform, as well as
providing an efficient plug-in for network management
applications or Jini connection technology.
Transparent distribution
The ChorusOS operating system's Inter- Process
Communication feature allows applications to be distributed
across multiple machines. The IPC feature identifies the
location of a process (local or remote), and then identifies
the shortest path and quickest execution time that can be
used to reach it, managing the communication in a way that
makes the process location entirely transparent to the
application.
Code re-use
ChorusOS operating system implementations are upward
compatible. Developers can therefore reuse applications on
the same core operating system, for a larger range of
equipment. For example, an ATM router card is developed,
using a small instance of the ChorusOS operating system.
Later another project, to develop a broadband ATM switch,
can build on the routing module, reusing the code.
Real-Time and IT Convergence
The ChorusOS operating system is the real-time operating system
companion to the Solaris™ operating system. With these two
superior operating system technologies, Sun provides a complete
telecommunications solution. Two complementary operating
systems, working hand in hand to provide the following
advantages:
One development environment
The ChorusOS operating system and the Solaris operating
system share the same hardware, the same set of POSIX
APIs, the same high availability APIs and the same
development and management frameworks. As a result,
development costs and time lags are reduced. Anything
developed on one operating system can be ported to the
other easily.
Design flexibility
The sharing between the two operating systems means
developers can decide exactly how much of their solution will
use the Solaris environment, and how much will be based on
the ChorusOS operating system, but use all the same
surrounding technology. Anything they develop will be
completely portable from one operating system to the other.
Gradual migration
By making it easy for developers to choose any percentage
split between the ChorusOS operating system and the
Solaris operating system, and by making all the surrounding
modules and technologies converge with both, Sun enables
developers and their operator clients to begin at any point in
the evolution from real-time embedded to computer- based
systems, and migrate slowly to where they want to go as they
replace obsolete systems and invest in new technologies.
Multiple OS personalities
The ChorusOS operating system supports other operating
system personalities with the same level of performance as a
corresponding monolithic implementation. A lot of work has
been done in order to provide efficient services that enable
system developers to implement high performance system
personalities on top of the ChorusOS microkernel. The
ChorusOS operating system supports implementation of
binary compatible operating system APIs. This unique
feature is of great value for embedded systems
manufacturers who want to run their real-time software on
standard and state of the art OS technologies, while at the
same time saving their investment in proprietary OS
solutions.