In order to reduce costs, a growing number of companies are trying to limit the number of different platforms on which they base applications. Each platform type requires a different tool chain for development; a different supply chain to manage; and different processes to deploy and maintain in the field.
Increasingly, telecom equipment manufacturers (TEMs) are implementing common platform strategies, where their goal is to minimize the number of platform types, yet still support the breadth of elements and applications required by the service providers. AdvancedTCA (ATCA) technology has been established as one of the key components of this approach—an industry managed open standard with the required performance, manageability, and availability characteristics required by the telecom industry. This should not be surprising, as all the major TEMs were involved in the specification of ATCA, and now most (if not all) top tier TEMs have some form of ATCA-based common platform initiative underway.
Adopting a common platform approach benefits the industry by increasing the number of applications that can be developed for that platform.
For example, initial deployments of ATCA based elements were focused on signalling and control-plane applications such as system-in-package (SiP) based softswitches and radio network controllers. Improvements to ATCA switch-blade technology have increased the application scope to include data-plane and packet-processing elements. In addition, we are now seeing a trend to push the common platform into more server-based applications such as billing engines, authentication databases, service delivery platforms, and IPTV content caching. These applications are much more diverse than other network element classes, and require a more flexible approach to data storage.
Storage can be complicated. It seems that every application has a different mass storage requirement and each development organization has different ideas on what topologies are acceptable. This means that there is no “one size fits all” storage solution. The approach adopted by storage providers for the enterprise server market is to provide a tiered storage strategy where the customer can choose the right capacity, performance, topology, and price point for any given application.
This white paper explains that although there are many different applications for systems based on ATCA server blades, it is possible to simplify them into a small number of storage application classes with similar needs, and propose a tiered storage strategy that can be employed. Finally, it gives recommendations for narrowing the choice for each storage class. First, though, it provides a quick primer for the various terms used in storage discussions and identifies their specific relevance.
Storage Primer
The purpose of any storage product is to reliably store and to provide access to such data that is required by an application in a timely and cost effective manner. This storage is normally implemented using hard drives (rotating magnetic media), although solid state drives (SSD) using flash memory technology are becoming rapidly more popular as their capacity increases and cost decreases.
Scalability can be discussed in two balancing dimensions: capacity and performance. You can scale capacity by increasing the number of drives in the storage array. Increasing the speed of the drives and/or number of CPU blades that access the storage array scales application performance. The performance of the storage array is usually governed by the type, interface, and spindle speed of the drives used as well as the amount of cache that the application can utilize.
For example, for certain applications, it may be more beneficial to fit more drives of smaller capacity than fewer drives of a larger capacity. The application characteristics determine how capacity and performance are related. Click here to read up on drive options.
Application characteristics also dictate how reliable the access and retention of data must be. A typical telecom application requires no single point of failure in the overall architecture and requires data to be accessible at all times. Of course, it would be best if no drive failures ever took place, unfortunately a hard-disk drive (HDD) is usually the most unreliable component in a system. Therefore, steps must be taken to against possible breakdown within a storage array.
This is usually achieved by means of redundant array of independent disks (RAID) technology coupled with the ability to hot-swap failed drives to get the storage array back to full operation as soon as possible. RAID can be implemented in software or hardware using dedicated RAID controller chips. In general, more sophisticated RAID implementation are best done using hardware RAID controller. Click here to read up on RAID.
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