Carrier Grade Linux
Encyclopedia
Carrier Grade Linux is a set of specifications which detail standards of availability
, scalability
, manageability, and service response characteristics which must be met in order for Linux
to be considered "carrier grade
" (i.e. ready for use within the telecommunication
s industry). The term is particularly applicable as telecom converges technically
with data networks
and commercial off-the-shelf
commoditized
component
s such as blade server
s.
Carrier-grade is a term for public network telecommunications products that require up to 5 nines
or 6 nines
(or 99.999 to 99.9999 percent) availability, which translates to downtime per year of 30 seconds (6 nines) to 5 minutes (5 nines). The term "5 nines" is usually associated with carrier-class servers, while "6 nines" is usually associated with carrier-class switches.
on proprietary hardware
systems that are currently used in telecommunication systems. These proprietary systems are monolithic (hardware, software and applications integrated very tightly) and operate well as a unit. However, they are hard to maintain and scale as telecommunications companies have to utilize the services of the vendor for even relatively minor enhancements to the system.
CGL seeks to progressively reduce and / or eliminate this dependence on proprietary systems and provide a path for easy deployment and scalability by utilizing cheap COTS
systems to assemble a telecommunications system.
The CGL effort was started by the Open Source Development Lab
(CGL Working Group). The specification is now in the combined Linux Foundation
. The latest specification release is CGL 4.0. Several CGL-registered Linux distributions exist, notably Debian, MontaVista, NexusWare and Wind River.
Availability
In telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...
, scalability
Scalability
In electronics scalability is the ability of a system, network, or process, to handle growing amount of work in a graceful manner or its ability to be enlarged to accommodate that growth...
, manageability, and service response characteristics which must be met in order for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
to be considered "carrier grade
Carrier grade
In telecommunication, a "carrier grade" or "carrier class" refers to a system, or a hardware or software component that is extremely reliable, well tested and proven in its capabilities...
" (i.e. ready for use within the telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s industry). The term is particularly applicable as telecom converges technically
Technological convergence
Technological convergence is the tendency for different technological systems to evolve towards performing similar tasks. Convergence can refer to previously separate technologies such as voice , data , and video that now share resources and interact with each other synergistically.The rise of...
with data networks
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
and commercial off-the-shelf
Commercial off-the-shelf
In the United States, Commercially available Off-The-Shelf is a Federal Acquisition Regulation term defining a nondevelopmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract...
commoditized
Commodity computing
Commodity computing is to use large numbers of already available computing components for parallel computing to get the greatest amount of useful computation at low cost. It is computing done in commodity computers as opposed to high-cost supermicrocomputers or boutique computers...
component
Electronic component
An electronic component is a basic electronic element and may be available in a discrete form having two or more electrical terminals . These are intended to be connected together, usually by soldering to a printed circuit board, in order to create an electronic circuit with a particular function...
s such as blade server
Blade server
A blade server is a stripped down server computer with a modular design optimized to minimize the use of physical space and energy. Whereas a standard rack-mount server can function with a power cord and network cable, blade servers have many components removed to save space, minimize power...
s.
Carrier-grade is a term for public network telecommunications products that require up to 5 nines
High availability
High availability is a system design approach and associated service implementation that ensures a prearranged level of operational performance will be met during a contractual measurement period....
or 6 nines
High availability
High availability is a system design approach and associated service implementation that ensures a prearranged level of operational performance will be met during a contractual measurement period....
(or 99.999 to 99.9999 percent) availability, which translates to downtime per year of 30 seconds (6 nines) to 5 minutes (5 nines). The term "5 nines" is usually associated with carrier-class servers, while "6 nines" is usually associated with carrier-class switches.
CGL Project and Goals
The primary motivation behind the CGL effort is to present an open architecture alternative to the closed, proprietary softwareProprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
on proprietary hardware
Proprietary hardware
Proprietary hardware is computer hardware which is owned by the proprietor.Historically, most early computer hardware was designed as proprietary until the 1980s, when IBM PC changed this paradigm...
systems that are currently used in telecommunication systems. These proprietary systems are monolithic (hardware, software and applications integrated very tightly) and operate well as a unit. However, they are hard to maintain and scale as telecommunications companies have to utilize the services of the vendor for even relatively minor enhancements to the system.
CGL seeks to progressively reduce and / or eliminate this dependence on proprietary systems and provide a path for easy deployment and scalability by utilizing cheap COTS
Commercial off-the-shelf
In the United States, Commercially available Off-The-Shelf is a Federal Acquisition Regulation term defining a nondevelopmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract...
systems to assemble a telecommunications system.
The CGL effort was started by the Open Source Development Lab
OSDL
Open Source Development Labs was a non-profit organization supported by a global consortium tasked to "accelerate the deployment of Linux for enterprise computing." Founded in 2000, its goals included "to be the recognized center-of-gravity for the Linux industry."On January 22, 2007, OSDL and the...
(CGL Working Group). The specification is now in the combined Linux Foundation
Linux Foundation
The Linux Foundation is a non-profit technology consortium chartered to foster the growth of Linux.Founded in 2007 by the merger of the Open Source Development Labs and the Free Standards Group , the Linux Foundation sponsors the work of Linux creator Linus Torvalds and is supported by leading...
. The latest specification release is CGL 4.0. Several CGL-registered Linux distributions exist, notably Debian, MontaVista, NexusWare and Wind River.
Applications and Services
The OSDL CGLWG defines three main types of applications that carrier-grade Linux will support — gateways, signaling servers, and management.- Gateway applications provide bridging services between different technologies or administrative domains. Gateway applications are characterized by supporting a large number of connections in real-time over a large number of interfaces, with the requirement of not losing any frames or packets. An example of a gateway application is a media gatewayMedia gatewayA Media gateway is a translation device or service that converts digital media streams between disparate telecommunications networks such as PSTN, SS7, Next Generation Networks or PBX...
, which converts conventional voice circuits using TDM to IP packets for transmission over an IP-switched network.
- Signaling server applications, which include SS7 products, handle control services for calls, such as routing, session control, and status. Signaling server applications are characterized by sub-millisecond real-time requirements and large numbers of simultaneous connections (10,000 or more). An example signaling server application would include control processing for a rack of line cards.
- Management applications handle traditional service and billing operations, as well as network management. Management applications are characterized by a much less stringent requirement for real-time, as well as by additional database and communication-oriented requirements. A typical management application might handle visitor and home location registers for mobile access, and authorization for customer access to billable services.
External links
- Carrier Grade Linux from the Linux Foundation