Carrier Grade Linux: Adoption and Deployments

By: Ibrahim Haddad
Thursday, July 14, 2005 12:04:22 PM EST
URL: http://www.linuxplanet.com/linuxplanet/reports/5931/1/

CGL is Real and Building Momentum...

The Open Source Development Lab (OSDL) released the latest version of the Carrier Grade Linux (CGL) Requirements Definition--version 3.1 on June 2, 2005. CGL 3.1 is the successor to CGL 2.0 and 1.1, the earliest versions of CGL which have been broadly adopted by the industry. At the time of writing, over 18 platform providers include CGL as part of their offerings and five Linux distributions are registered as implementing CGL 2.0 (with two more in progress). In addition, an increasing number of Carriers and Service Providers are deploying CGL based server nodes to offer communication services. In a previous article published in LinuxPlanet, I examined the state of Linux in telecom and reviewed the specifications in the CGL requirements document. In this article, I will provide an overview of CGL distributions, deployments and some of the challenges ahead.

Traditionally, communications and data service networks were built on proprietary platforms that had to meet very specific requirements in areas such as availability, reliability, performance, and service response time. Those proprietary systems were composed of highly-purposed hardware, operating system, middleware, and often included proprietary technologies and interfaces. Such proprietary approaches to system architecture fostered vendor lock-in, very served to limit design flexibility and freedom, and produced platforms that were and are very expensive to maintain and expand (see Figure 1).

Today, those same service providers and carriers are challenged to drive down costs while still maintaining carrier class characteristics for platforms to provide service and mission critical applications in an all-IP environment. They are in a position today where they must move away from specialized proprietary architectures, and towards commercial-off-the-shelf (COTS) approaches and building practices (Figure 2) for several reasons, driven by three key motivations:

  • Faster time to market: Service providers and carriers need to be able to deliver new services based on common standardized platforms. They are in a constant race to deliver faster to the market. Building with propritary and specilized technologies that are offered by a very limited number of provides is one obstacle from this perspective.
  • Reduce costs: Communications service providers need to reduce the design and operation costs by using commercial-off-the-shelf hardware and software components that are offered by multiple providers and are all compliant or registered towards standards of industry agreed specifications.

As a result, proprietary legacy systems no longer offer a viable approach. They are expensive to buy, maintain, and scale. As a result, the industry is moving away from specialized proprietary systems toward open platforms that are based on industry established standards and common practices. Figure 2 illustrates the first steps that were taken by the industry to move away from specialized architectures towards COTS practices and building blocks: the figure present a trend to move from a network element that was designed and built using proprietary components towards a network element which deploys standardized highly available hardware and Carrier Grade Linux.

As we move forward into the future (Figure 3), we will see the introduction of standard-based hardware manamagement, standard-based middleware and interfaces, and standardized protocols. The end result is a application enabling platform that encourages the rapid adoption of industry standards, promotes innovations, and promises lower costs.

Figure 4 illustrates a sample telecom platform, one subrack that consists of multiple network elements. Each network element runs a different type of application; all network elements have the same open architecture built around the concept of standardized building blocks and COTS hardware and software components.

Carrier Grade Linux

Carrier Grade Linux (CGL) stands at the center of the move to open architectures. About three years ago, representatives from platform vendors, Linux distribution suppliers, and network equipment providers, set out to define how "Carrier Grade Linux" could enable environments with higher availability, serviceability, and scalability requirements. As a result, the OSDL CGL working group was formed.

Since its formation, the working group has produced three versions of a specification to define these required capabilities. In response, Linux distribution suppliers are now demonstrating that they can meet the emerging needs of telecommunications by registering (disclosing publicly) how their Linux-based software platform products address the requirements as defined in the Carrier Grade Linux Requirements Definition.

Today, the CGL working group has grown to include over three dozen representatives from platform vendors, Linux distribution suppliers, network equipment providers, carriers and development community members worldwide. This expanded group has now released the Carrier Grade Linux Requirements Definition version 3.1. For clarity and ease of use, the specification has been split into seven separate topical documents: Availability, Clusters, Serviceability, Performance, Standards, Hardware, and Security.

The initiative started with the vision that communication services will be delivered using open standard carrier grade platforms. A Linux kernel with Carrier Grade characteristics is an essential building block component of such platforms and architectures. The focus with CGL (Figure 5) is to enhance the capabilities of Linux in several key areas such as availability, security and reliability, with the goal of making Linux an attractive alternative to proprietary operating systems for telecom servers.

As for mobile networks, CGL is targeted for all types of servers nodes running at all layers of a next generation network: service, control and connectivity layers:

  • The user application layer contains services for which the end user will be willing to pay.
  • The control layer with MSC servers, support servers, HLR etc. These servers are needed to provide any service to a subscriber.
  • Connectivity layer supports high quality voice & data delivery.

At the time of writing, multiple providers are offering CGL-based server nodes for Service Providers and Carriers to deploy. Most deployments today are concentrated at the control layers and some deployments at the application layer.

As the work progresses on the CGL requirements and CGL has more capabilities and advanced features areas of RAS, security, performance, and real time, we expect the deployment of CGL to expand to the connectivity layer.

Carrier Grade Linux 2005 Major Milestones

Figure 8 presents the major milestones of the CGL initiative in 2005. The major milestones until the writing of this article include:

  • February 2005:
  • May 2005:
    • The CGL initiative organized meetings with Carriers and Network Equipment Providers in Paris on May 13 and 16. The goals of the meeting were to provide input for the CGL Initiative, exchange best practices, identify enablers for escalated Linux/CGL deployment and identify nes areas that CGL can address. The meetings were attended by carriers such as British Telecom, France Telecom, and NTT DoCoMo, and my Network Equipment Providers such as Motorola, NEC, NTT Labs, and Nortel. The meetings provided valuable input to the initiative and we are planning similar meetings in August and October 2005.
    • The second face to face meeting of 2005 took place also in Paris and the CGL 3.1 Requirement Document was ratified.
  • June 2005
    • The CGL 3.1 Requirement Document was released. It is available from http://www.osdl.org/lab_activities/carrier_grade_linux/documents.html/document_view.
    • SuperComm 2005 featured two Panel Discussions: "Accelerating Linux Deployment in Communications" and "The Business Case for Linux" to meet the growing interest in CGL applications for telecommunications infrastructure. In addition, the keynote presentation at the Linux Solutions Telecom Conference on "The State of the Penguin" was focused on CGL and Linux in the communication space.

As for the planned CGL activities for the remainder of 2005:

  • July 2005:
    • A presentation to the MultiService Switching Forum on Carrier Grade Linux and a discussion to explore possible collaboration model between the two organizations, especially that MSF members include a large number of Carriers and NEPs.
    • A presentation at the Ottawa Linux Symposium", Carrier Grade Linux: The Full Story!
  • August 2005:
    • A feature presentation at HP World 2005 on Carrier Grade Linux Solutions in Mobile Infrastructures: Markets Trends, Challenges and Global Deployments
    • The second meeting with Carriers and NEPs is being organized at the time of writing.
    • A presence at the LWE in San Francisco with presentations.
  • September 2005:
    • A presentation on Highly Available Linux Clusters and the CGL Cluster Model at the IEEE Cluster Conference to take place in September 2005 in Boston, MA.
  • October 2005:
    • Planning a third face to face meeting with Carrier and NEPs in Beijing, China.
    • The third annual CGL initiative face to face meeting will take place in Beijing, China.

Beyond CGL 3.1

As for beyond 3.1, the priorities of the CGL working group as identified based on the market input and the feedback received from participating companies in the CGL initiative are: Real-time capabilities, testing CGL workloads, device driver hardening and availability, Linux performance and scalability, in addition to further enhancement to Security and Manageability (see Figure 9).

CGL Registration Process

The registration disclosure is a self-registration process. Carrier Grade Linux Registration is the full disclosure of all the priority 1 requirements in the Carrier Grade Linux Requirements Definition. Disclosure for each priority 1 requirement indicates whether or not the requirement has been implemented. For each met requirement, then the document defines the data needed for registration disclosure. Linux distribution vendors provide the disclosure information on their web site and on the OSDL site and this public disclosure information is owned and maintained by each Linux distribution vendor. If a Linux distributor vendor did not implement a certain Priority 1 requirement(s), the vendor must disclose the reason for its absence. Linux distribution vendors that have registered with full public disclosure of all priority 1 requirements may describe their product as OSDL CGL Registered.

CGL Distributions

Currently, five Linux distributors provide CGL 2.0 registered distributions (see Figure 10). OSDL maintains a web site that lists CGL registered distributions and links to their disclosure documents: http://www.osdl.org/lab_activities/carrier_grade_linux/registration.html

Providers of CGL-Based Platforms and Products

Platform providers also use CGL registered distributions on their platforms. Those platforms end up being offered to NEPs and Carriers and are deployed on carrier networks.

Figure 11 illustrates the companies that have announced the use of either CGL based platforms in their offerings or use of their own Linux distributions based on CGL. The list is quite interesting from a geographical perspective, as CGL-based products and platforms are coming from North America, Europe and Asia.

Deployments with CGL

NEC Case Study

In May 2005, members of the CGL initiatives (including this author) had the opportunity to meet with some service providers, carriers and NEPs. The goals of the meetings were to receive input about the future direction of the CGL initiative beyond CGL 3.1 and to receive feedback regarding current CGL deployments.

One of the more interesting deploying stories came from NEC. This Japan-based member NEP is providing GGSN (Gateway GPRS Serving Node) and SGSN (Servicing GPRS Serving Node) CGL-based server nodes to major Asian Carriers. NEC has already deployed over 100 nodes servicing over 10 million subscribers. These deployments have been in a commercial setting for over six months. Based on this positive experience, NEC's customers have plans to implement other nodes in their mobile infrastructure using the sample platform architecture (see Figure 12) based on COTS hardware and CGL.

BT Case Study

Another deployment story comes from British Telecom Global who has been running a pilot project in Belgium for a COTS-based platform to provide voice services. The architecture of the platform is shown in Figure 13 and has Carrier Grade Linux as a core component.

The pilot project has been successful and the platform has been providing service in a mission-critical environment for months. BT Global is in the process of investigating the roll-out of this platform across their EU network.

During SuperComm 2005 (June 6-9) in Chicago, Mr. Paul Reynolds (Chief Executive of BT Wholesale) was interviewed by the SuperComm Daily (on June 7):

"We knew we had to break from normal conventions and view whole life cost, and build everything as much as possible on open standards, where we had access to source code and could expect plug and play compatibility."

Open platforms based on industry defined standards and building practices are the way forward; CGL is one core component of such platforms.

Conclusion

Today, three and a half years since the CGL initiative began, how might we rate the progress of CGL?

  • The CGL initiative has released three major CGL requirement definitions, 1.1, 2.0 and the latest is 3.1
  • There are five providers of CGL distributions that are registered against the CGL 2.0 requirement document--in addition to two distribution providers are in the process of completing their registrations
  • Over 20 platform providers and NEPs are offering CGL-based platforms and solutions
  • Carriers and Service Providers are deploying CGL-based platforms on their networks providing communications services to their subscribers

Linux with carrier grade characteristics provides an essential building block that allows TEMs and NEPs to build open communication platforms. The CGL initiative is a community effort: TEMs, NEPs and Carriers supply requirements; OSDL members gather requirements and create specifications; OSDL members, community, and ISVs implement projects; Distribution suppliers build and register CGL platforms; TEMs, NEPs and Carriers deploy. The initiative is based on cooperation between companies and individuals and participation is open to everyone.

Carrier Grade Linux is real! CGL 1.1 and CGL 2.0 based platforms and applications are shipping worldwide; CGL 3.1 distributions and platforms will be available in 2006.

Summing it best is this statement from a Computerworld The interview with Brian McFadden, Nortel CTO, dated January 14, 2005. McFadden was asked about technologies to watch in 2005:

"Another technology that will be important in 2005 is Linux in networks. It is now carrier-grade and picking up momentum. It is real, and it will continue to integrate in enterprise and carrier products."

The goal of the CGL initiative is to accelerate the development and deployment of Linux in the telecommunications' industry. So far, we are on target! The initiative is based on cooperation between companies and individuals and participation is open to everyone. Please consider this as an invitation to get involved in this effort and contribute to making Linux a viable operating system for communication platforms.

Links

References

About the author: Ibrahim Haddad is an OSDL member leading the Carrier Grade Linux Initiative and promoting the development and adoption of Linux in the communication industry. Prior to joining OSDL, he was a senior researcher at the Research and Innovation Department, of Ericsson Research Corporate, in Montreal, Canada, where he was involved with the server system architecture for 3G wireless IP networks. Ibrahim is a Contributing Editor for the Linux Journal and Linux Today, and is a frequent contributor to the O'Reilly Network, Unix Sys admin, LinuxWorld magazine, and Linux User and Developer. He is also a featured speaker and panelist at conferences such as Linux World, SuperComm, Real World Linux, Ottawa Linux Symposium, in addition to the more academic conferences held by IEEE, ACM, and USENIX. He is currently a Doctoral of Science Candidate at Concordia University in Montreal, Canada, researching Scalable Architectures for High-Availability Web Server Clusters.

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