Why bother with Interoperability?

 

In the Telecom industry, particularly as it relates to IMS interoperability, some vendors are more open to “sharing” than others, much like children, interacting on a playground. But unlike at the playground, IMS presents many new challenges that exacerbate already existent issues.

 

With interoperability, ideally service providers should be able to construct their networks using a variety of vendors. The service provider could then choose among many best-of-breed vendors for a specific task, and if one does not perform as desired, they could then switch to another without a problem. The ease of using multiple vendors leads to increased competition, improvements in product offerings, and lower pricing. While this is not an ideal situation for standalone vendors, standards-based technologies have provided a demand for increased overall industry spending, which means that ultimately all vendors benefit, despite the initial challenges of this approach.

 

IMS was designed with interoperability in mind. In fact, a large part of its architecture derived from the internal software elements that many vendors had in common, but did not expose externally. These elements essentially form a set of building blocks that can be used to create a network, and IMS is designed to allow these blocks to be interchangeable from one vendor to another. Vendors achieve this end by following technical specifications and implementing their products accordingly. And, in theory, if everyone follows the specs, they should be able to interoperate.

 

Unfortunately, this is not as easy as it may seem. First, there are thousands of pages of detailed specifications across a handful of major spec-writing bodies and dozens of influencing industry organizations. Just keeping track of all the specifications is a major undertaking, and that is without the inevitable mistakes and incomplete areas in these documents. In addition, the standards are evolving over time as the industry matures, so other vendors also have to worry about what versions of the spec they are working with and their increasing need to support multiple versions of the specs.

 

Secondly, vendors need to take unique approaches to implementing these specifications to differentiate themselves from their competitors. The differentiation allows them to not only beat the opposition, but to also potentially charge a premium for this uniqueness. Therefore, it is not surprising that the vendors have conflicting interpretations of technical standards, and often they may refute the standard altogether if their approach is significantly better. Depending upon the nature of their advantage, these vendors may or may not share their findings and lobby to have the approach incorporated into future standards. In addition, these benefits take time to develop, so most major vendors are experimenting with new approaches long before the standards bodies form any final conclusions.

 

We should also keep in mind that no organization ever operates with perfect efficiency, and companies often implement new technologies in a less-than-ideal fashion. Within a typical telecom vendor, multiple development groups are working simultaneously on different subcomponents that join together to make a product, or product suite. As anyone who has worked in this type of environment knows, getting all of the subcomponents within a single vendor to come together in a cohesive fashion is an enormous undertaking, so you can imagine the challenges involved when you combine products from a plethora of vendors.

 

Despite the seemingly discouraging situation, vendors and service providers are proving interoperability is possible. The telecom industry has taken two major approaches to solving the interoperability problem by:

 

 

Realizing the challenges ahead, many vendors have taken the first approach and have joined public and private consortiums that promote interoperability among members, which are often led by the major network equipment manufacturers. Others are formed upon the request of carriers, and several vendors have even been successful enough to be mandated by service providers. These groups typically collate their equipment in a common lab and share interoperability test findings and implementation best-practices with the partner-group.

 

The other alternative is to participate in the above-mentioned open interoperability events. The Multi Service Forum recently completed its 3rd Global MSF Interoperability event this past October. In this event, dozens of major carriers, equipment vendors, and test companies worked together to develop a five-stage test plan of the IMS architecture that was executed over a 10-day period. The event illustrated the challenges introduced by various interpretations of the specifications that existed between vendors. Interestingly, while the initial work of making basic registration and call setup took longer to get up and running than expected, more advanced stages of testing went quicker than planned in many cases. Overall, the event was a great success, proving that close vendor coordination can overcome many interoperability challenges.

 

In addition, the IMS Forum is hosting a Plugfest event taking place January 15th through 20th, 2007, at the University of New Hampshire’s Interoperability Lab (UNH-IOL), one of the industry’s premier test centers. During Plugfest, several unique IMS scenarios will be tested, including interaction with wireless and wireline, as well as the functionality of the reference IMS test network, starting with fixed and mobile voice services. The event will also include testing services, such as presence, instant messaging, hosted IP PBX (News - Alert), VoIP supplemental services, multimedia, and roaming across multiple networks, such as Mobile, WiFi, Wireline and Cable broadband.

 

IMS interoperability will not come easy, and there are numerous business and technical challenges that need to be addressed in order to achieve IMS’s ideal vision. Fortunately, the industry has already begun this journey. Events like the MSF’s GMI prove that interoperability is possible, even in the public eye, and the IMS Forum’s upcoming Plugfest will help to further reinforce that technology, private vendor and service-provider driven interoperability labs are making IMS interoperability happen.

 

Time will tell how long vendors can “play-nice” with each other. For now, it appears they are leveraging their playground rules well.