The service delivery platform (SDP) was born out of the need to rapidly create advanced multimedia services: IPTV, mobile video, gaming, location-based services. But is there a role for SDPs in the cloud? Potentially, but they can't be service delivery platforms as we know them today. To remain relevant to cloud providers, the service delivery platform must evolve.
It's likely orchestration will cement the role of service delivery platforms in XaaS.
Decades ago, the primary service of networks was voice communication, and the features of that service were embedded in the central-office and tandem switches. As network services evolved and became more software-based, this monolithic model was forced to change; even before the advent of the Internet, standards groups were working on how to define the role of computer-hosted intelligence in network services. These circumstances gave rise to the service delivery platform.
The roots of the service delivery platform lay in traditional voice services, and today those roots are most evident in the role that SDPs play in mobile voice services, functioning as a host for components of the IP Multimedia Subsystem (IMS). The future of SDPs, however, will likely be tied to two next-generation technologies: over-the-top (OTT) content delivery and cloud computing. The combination of OTT and cloud forms a union that can be called XaaS -- meaning Anything as a Service or Everything as a Service -- reveals the direction service delivery platforms must take.
Why XaaS needs a service delivery platform
The XaaS model presumes that providers will increasingly deliver next-generation services to mobile devices. The data fed to these devices will come from a variety of sources, and the compute resources processing it would likely be distributed as well. Supporting this model with simple, best-effort Internet connectivity is likely to frustrate customers, however, since the failure of any component to play its role will cause the service to fail overall.
Reliability is paramount to supporting XaaS applications -- from the network up to the application components -- as the service must keep users happy and be profitable for the provider. Given these requirements, the service delivery platform may be an ideal platform for XaaS. Service delivery platforms are inherently designed for a higher standard of availability than traditional servers, and they are also built to meet the high-reliability requirements of signaling in telecom services.
Most SDPs use open platforms like Linux, UNIX or a derivative operating system, and in theory, most could be equipped with cloud software and support Web-compatible interfaces. The only thing that today's service delivery platforms lack is an explicit conception of Web services that's on par with their explicit conception of session-based services like Voice over IP (VoIP) and IMS. It seems unlikely that IMS could generate a competitive platform for Web services, and SDPs must significantly enhance basic server or cloud server capabilities if they are to be justified as a competitive option to ordinary servers.
SDPs in XaaS: App stores, certification or orchestration?
To date, the market has identified three applications for which the merits of SDPs are considered valuable: the development of app stores, certification of features and service elements and orchestration of services through composition of elements.
App stores are interesting to service providers because they address a market related to their mobile device deployment and they link to their billing processes. While it would be possible to host app stores on standard servers, as Google and Apple do, the network operator faces a higher standard of reliability, and that is enough to justify a service delivery platform. The issue is that app stores are simply an application -- not the foundation for a service architecture.
Certification is a potentially more compelling step in the evolution of the service delivery platform to an XaaS platform. Certification platforms are responsible for managing the elements of a service network, including the software, servers and databases that fall outside the scope of traditional network management and network operations center tools. Service delivery platforms could be deployed in parallel with traditional servers and could be used to ensure these devices were available and functional, thus overseeing service operation at a high level. But even in this mission, the SDP is outside the service itself -- ensuring resources are available, but not participating.
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It's likely orchestration will cement the role of service delivery platforms in XaaS. In online services, orchestration is the composition of a service or experience through an orderly linkage of service components and the movement of requests and responses among those components. Unlike certification, which focuses on verification of availability, orchestration actually creates the service or experience, which means it's critical to building what users see -- and buy.
Orchestration also addresses the underlying challenges of building complex, componentized applications that XaaS creates in the first place. An SDP-orchestrated service could protect against the failure of a single component by simply monitoring it to ensure that requests sent to that component generate responses, or by employing a failover plan if the requests don't respond properly. This means that more traditional Web servers could participate in XaaS without creating the avalanche of failure risk that typically accompanies deployment of multi-part services.
When used in orchestration, service delivery platforms can act as hosts for the service components whose operation is most critical to XaaS and where it's necessary to integrate components with a high-availability network or with OSS/BSS elements. Orchestration is the future of the service delivery platform, and most SDP vendors now acknowledge that in their marketing materials.
SDPs for orchestration: Many obstacles ahead
The challenge that remains is organizing and standardizing orchestration itself -- something that's been attempted for several years without much success. Most SDP vendors offer some orchestration tools, but many of these platforms are still complex and expensive, making them less competitive in the real world of XaaS.
Meanwhile, work on orchestration in the more general cloud and server markets is progressing, particularly through work around DevOps and application integration. Some vendors have also taken the lead on this, including Alcatel-Lucent, Cisco Systems, Dell, Hewlett-Packard, IBM, Microsoft Corp and Oracle. The service delivery platform has to move to the front of these activities if it's to remain relevant.
Service delivery platforms may also have to resolve the conflicts associated with mobile Web services outside of IMS. Many vendors in the IMS world have resisted efforts to define "services" except as a series of sessions -- a model the OTT giants that drive the XaaS market today have rejected. If this debate interferes with the progress of orchestration support on SDPs, it could relegate the service delivery platform to softswitch-like applications and reduce its relevance in the XaaS-driven future.
About the author: Tom Nolle is president of CIMI Corporation, a strategic consulting firm specializing in telecom and data communications since 1982. He is the publisher of Netwatcher, a journal addressing advanced telecom strategy issues.