Development Platforms: Integrated xTCA Architectures Offer a Choice for Highly Reliable and Scalable Network Designs

By: Sven Freudenfeld

Network services, such as IPTV (News - Alert), social networking and 4G presence-enabled services continue to drive growth, setting the foundation for a broad spectrum of content delivery platforms. Competition is intensifying as Network Equipment Providers (NEPs) and Telecom Equipment Manufacturers (TEMs) must keep up with these time-to-market demands, Quality of Experience (QoE) expectations and increasing complexity of the network, while focusing on differentiating their application.

However, building a distributed, highly available and reliable system to deliver network services is a complex and often time-consuming task. Developers of content delivery platforms looking to add new revenue streams cannot afford 18 to 24-month deployment cycles. Designing the entire system in-house is no longer a realistic use of resources nor is it a cost-effective option. Instead, network equipment designers are looking to a Commercial Off-The-Shelf (COTS) approach that is driven by standards in order to accelerate the development cycle, reduce risk and ultimately shorten time-to-market.

The Advance Telecommunications Computing Architecture (AdvancedTCA (News - Alert), or ATCA) was defined by the PCI Industrial Computers Manufacturing Group (PICMG) to address the need for COTS solutions to address the specific needs of telecom. Advanced Mezzanine Cards (AMC) modules, ATCA plug-in expansion cards, address the need for high levels of modularity and configurability. AMCs can extend the benefits of the AdvancedTCA fabric to individual modules, enabling designers to customize, scale, upgrade and service their systems. Micro Telecommunications Architecture (MicroTCA (News - Alert)) is a complementary, smaller scale platform, ratified in July 2006 and built around the use of AMC modules. Together, AdvancedTCA, MicroTCA and AMCs make up the xTCA ecosystem offering the freedom of choice to source from multiple vendors.

AdvancedTCA Building Blocks

The advent of the AdvancedTCA specification to meet carrier-class requirements provides an ecosystem of flexible hardware building blocks for the integration of complex high-performance systems. The advantages of AdvancedTCA are its extremely high computing power, high communication bandwidth, and high availability. Manufacturers who take advantage of the latest multi-core processors in these COTS building blocks from multi-vendor ATCA component providers will be able to build high performance, scalable systems without upgrading the framework or increasing floor space.

The AdvancedTCA specification defines a number of backplane protocol and topology choices, providing flexibility depending upon the needs of the application. The processing boards communicate over the backplane via high bandwidth channels, typically Gigabit Ethernet or 10 Gigabit Ethernet — in either a star, dual star, or full mesh topology. Peripherals such as packet processing modules and storage drives using iSCSI both communicate over the backplane, typically via PCI Express, GbE, 10GbE, Serial Rapid IO, SATA, or SAS (News - Alert).

The redundancy of the dual star and full mesh topologies are a key factor in making AdvancedTCA systems highly available. Other features of AdvancedTCA that support high availability include the ability to hot swap all FRUs (Field-Replaceable Units), redundant IPMI (Intelligent Platform Management Interface) buses for blade management, and shelf management. These features, if properly leveraged through judicious use of middleware and/or application support, can provide systems with up to five nines (99.999%) availability.

MicroTCA — Compact Size and Flexibility

One of the biggest advantages of MicroTCA is its small form-factor, high bandwidth and high availability. Despite its small size, MicroTCA offers a wide range of bandwidth, options both in terms of compute bandwidth and communication bandwidth. The abiliyt to plug up to 12 compute boards into a single backplane give MicroTCA a tremendous amount of potential computing resources, especially when each board is using a multicore processor. Communication bandwidth capabilities range from 1 Gbps to 10 Gbps using multiple switch protocols such as 1GbE, 10GbE or brio. With this amount of compute and communication power, MicroTCA has more than enough bandwidth for most demanding applications.

MicroTCA also offers design flexibility with several packaging options for different environments and support for a number of interconnect technologies, including Ethernet, PCIe and RapidIO.

Potential applications are as varied as WiMAX (News - Alert) and cellular base stations, data centers and the enterprise, along with VoIP and IMS applications. One area of potential growth for MicroTCA within the telecom market is IPTV-based or content delivery services. The challenge is deploying an end-to-end IP-managed network that can deliver superior quality of service and quality of experience for the consumer. Since it offers high availability, low-power, ultra dense processing and lower operating costs, designers can use MicroTCA for residential media gateways. The smaller form-factor and lower entry cost in footprint of MicroTCA communications servers supports a “pay-as-you-grow” business model, allowing service providers to enter a market with less initial capital expenditure and to expand their computing platform capabilities in small, low-cost increments as demand for the new service increases.

Other Critical Building Blocks

Selecting the appropriate hardware to support a given set of communications protocols and applications is just the beginning of the engineering workload associated with launching a new carrier-class platform. Along with the robust, highly intelligent, high availability and reliable hardware components provided by xTCA also comes a degree of complexity in the details of virtually every facet of the system. Besides the standards-based COTS system management building blocks, there are a number of other elements which must all work together seamlessly (see Figure 1).

System design engineers must also integrate the associated OS and in some instances the Board Support Package (BSP) with the associated supporting drivers for the components on the board or system and develop middleware to integrate the hardware with the application reliably. The management capabilities for all the hardware, fabrics, software, and system components are quite sophisticated and require an expertise of complex standards to pull all the building blocks together into a cohesive system.

However, standards-based middleware provides TEMs with off-the-shelf high availability software to complement its carrier-grade equipment. Frequently there is a lapse between the availability of the hardware and the date with which it is possible to deploy applications because of the development costs associated with the back-end software. This gap can be filled with middleware platforms that provide chassis management functions, inter-process communications, and services that are scalable from deeply embedded to large, complex systems. The availability of open system solutions and open architecture middleware platforms make it possible to integrate essential services without being a technical expert in communications.

Interoperability is Critical for Mainstream Adoption

One of the keys to the adoption of any open standards computing platform is interoperability. Because the system configuration options using the xTCA approach are diverse, multi-vendor interoperability is key (see Figure 2).

The Communications Platform Trade Association (CP-TA) is a global association of communications platform and building block providers dedicated to accelerating the adoption of SIG-governed, open specification-based communication platforms through interoperability and testing. CP-TA has delivered interoperability documents for ATCA and is currently addressing AMC and MicroTCA specifications. COTS building blocks tested according to the CP-TA Test Procedure Manual and validated according to the Interoperability Compliance Document.

Beside the CP-TA, there are a number of other working groups dedicated to solving issues related to xTCA interoperability and compliance (see Figure 3). The SCOPE Alliance (News - Alert) has defined a reference architecture for a generic Carrier Grade Base Platform (CGBP). This architecture, which includes hardware, operating system, operations and maintenance functions and tools, also specifies middleware as a fundamental component for service availability. SCOPE also creates profiles for The Service Availability Forum (SA Forum), the main organization active in the middleware standardization effort.

The Daunting Task of Integration

While there are significant benefits in using standardized xTCA building blocks, developing a complete system still requires an integration effort that can take from six to 12 months to make sure all of the elements work seamlessly together. In addition, integrating the hardware platform can require a great deal of support in the form of program management, functional experts, quality assurance, tools and deployment support all of which adds up to a tremendous amount of precious personnel, time and money resources.

Integration efforts must start from interoperability on the hardware level when using multiple sources for the system components. There are also the considerations of thermal, mechanical, fabric connectivity and IPMI interoperability. Having all the tools to perform this task is already a significant investment not to mention the engineering time to perform validation and integration. When integrating multi-sourced standard components, further challenges arise when the design team must identify which “vendor” is at fault when a problem arises.

The next level of integration requires that the preferred OS works properly and is supported on the desired boards. The manageability within the system can become a major undertaking. Even when standard-based components are implemented, the system management (middleware), HPI (News - Alert), and shelf management all must be validated as a cohesive management unit.

The following provides an example of the associated costs of resources and lost revenue due to incremental time-to-market in a real-world network application developed entirely in-house:

From the initial procurement phase (including component selection, procurement and learning curve) to carrier-class integration and validation of the hardware platform all the way through deployment support (including debug and component upgrade), the incremental time to market can add up to more than 700 days. The lost revenue due to this delay can add up to a loss of $1 Million for every month not in the market, which totals to nearly $24 Million.

For a product to be successful, it needs to be an integrated solution with hardware, middleware, OS, etc. As a result, partnering with hardware and middleware experts that can provide integrated, validated and tested platforms is very important to the long-term success of the application (see sidebar).

Summary

It is a complex and laborious undertaking to build a distributed, highly available and reliable system to deliver network services. The COTS approach has proven to help reduce risk and accelerate time-to-market. As the COTS xTCA ecosystem continues to grow, multi-vendor interoperability becomes essential. CP-TA tested building blocks offers developers with the freedom of choice to select the best of breed in price and performance, alleviating the issues about hardware integration or interoperability and allowing them to focus on differentiating their application. Collaborating with an experienced platform integration partner can help ensure the application can be successfully brought to market.

Sven Freudenfeld is responsible for North American Business Development for the Kontron (News - Alert) AG line of AdvancedTCA, AdvancedMC, MicroTCA, and Pre-Integrated OM Solutions. Sven possesses more than 15 years of experience with voice, data and wireless communications, having worked extensively with Nortel (News - Alert) Networks in Systems Engineering, Sanmina-SCI in Test Engineering, and Deutsche Telekom in Network engineering. Sven holds an electrical engineering degree from Germany, is VP of The Communications Platforms Trade Association (News - Alert) (CP-TA) and is the Chair of the CP-TA marketing workgroup focusing on the interoperability of COTS standard building blocks. His company, Kontron (www.kontron.com), designs and manufactures standard-based and custom embedded and communication solutions for OEMs, systems integrators, and application providers in a variety of markets. IT

» Internet Telephony Magazine Table of Contents