Switch Boards Blur the line with Routers by RTC Media

Technology InContext

Figure 3

Compute Blade

System Manager

Compute Blade

Switch Blade

Switch Blade + System Manager

Switch Blade

Switch Blade + System Manager

System Manager

Compute Blade

Open site frees up blade slots.

by adding or removing modules as system needs or requirements change. This flexibility makes it easier to tailor systems for large and small customers. Equipment makers can adjust system capacity and capability within the same platform and more quickly address the needs of different market segments and improve their time-to-market. Carrier blades can also be used to combine functionality that may have previously resided on separate blades. A single carrier blade can accommodate modules for both control and data planes resulting in a more consolidated solution. As an alternative to AMC carrier blades, board vendors are adding open module sites to common building blocks like switch and compute blades. For example, the RadiSys Promentum ATCA2210 10 Gigabit switch and control module has a COM Express site that enables equipment makers to add intelligence to the switch by adding a control module or system manager to the baseboard (Figure 2). In addition to providing a higher level of integration, this capability may free up a slot by eliminating the need for a separate blade. In Figure 3, the switch and sys-

tem manager functions are consolidated, usually providing cost reductions and saving a board slot to be used for revenue generation. For highly redundant systems, two slots can be freed up. High-performance compute blades often include an AMC expansion site that can be populated with hard disk drives or Ethernet cards. Adding storage and I/O directly on the compute blade helps reduce cabling and increases system density. In other cases, an adjunct processor can be placed in the expansion slot, providing an offload for functions like security processing. Flexible baseboards may support mezzanine modules other than AMC, which allows developers to forgo implementing some complex features such as hot swap. These modules can also provide TEMs a simpler, faster and cheaper means to integrate their IP without developing a full-blown ATCA blade. TEMS developing next-generation systems may still need to maintain support for legacy signaling software. Instead of designing an ATCA version of older proprietary boards, system developers can use blades that provide highest density media processing and ease the

Common ATCA Blade Types Blades can be categorized as hub boards that provide the central switching resource in a shelf or node boards that communicate to other nodes through backplane interfaces. Here are examples of common ATCA building blocks: •C arrier blade: A node board containing several (2-8) mezzanine slots, typically Advanced Mezzanine Card (AMC), for integrating a wide range of functionality like processing, storage and I/O functionality. • Compute blade: A node board consisting of a single board computer used for general-purpose processing (a.k.a. CPU/server blade). • DSP Blade: A node board integrating digital signal processors (DSPs) for processing media in applications including voice (VoIP) and video (MPEG). • Line Card: A node board interfacing to subscriber lines supporting services such as POTS, ISDN and DSL. • Networking blade: A node board processing networking I/O—Ethernet, T1/E1 and OC3—often employing network processing units (NPUs). • Storage blade: A node board providing high-capacity storage, normally across storage-specific interfaces such as Fibre Channel. • Switch blade: A hub board generally supporting 12-20 base interfaces, a similar number of fabric interfaces, as well as some auxiliary interfaces. • System Manager Blade: A hub board implementing a management processing hierarchy including Intelligent Platform Management Interface (IPMI) controllers, the shelf management controller and the shelf manager.

November 2007