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January 2007
Volume 10 / Number 1

Billing and OSS - the Last Barrier to VoIP and IMS

By Richard “Zippy” Grigonis: ( Page 1 || Page 2 || Page 3 || Page 4 || Page 5 || Page 6 || Page 7)


Top-Down and End-to-End

Stepping back for a moment to see the “big picture,” ultimately everyone wants “end-to-end” OSS and BSS functionality. But to truly offer end-to-end network management and billing, however, sometimes even great vendors in this area have to form alliances. For example, in 2006, Telcordia Technologies and Accenture formed a strategic alliance to build and deliver end-to-end OSS, network management and business support solutions for the world’s communications service providers. Telcordia’s OSS applications are incorporated into Accenture’s suite of software for communications service providers, called Accenture Communications Solutions. By combining its technology network, business process and broadband experience with Telcordia's product portfolio, both companies feel that they can help carriers migrate to next-generation IP networks “with fully-integrated platforms enabling market differentiation and revenue maximization.” Moreover, The market research firm OSS Observer released a report last year noting that Telcordia was the clear market leader in inventory, network resource management and service fulfillment. This probably shouldn’t be surprising, since even back in the “old days” Telcordia’s (i.e. Bellcore’s) TIRKS inventory system was an immensely popular OSS. Telcordia also made a key acquisition in this area, Granite Systems and its Granite’s Service Resource Management technologies.

With all of our talk of software, we mustn’t forget that hardware must be up to the task of running software in provider environmnets. Sonus ( for example, recently announced the latest release of its carrier class billing platform, enabling network operators to streamline the integration of next generation applications with existing OSSs. By leveraging the Sonus Insight Management System™, service providers can support the rapid integration of new multimedia services into existing billing platforms. Sonus’ billing mediation solution, the DataStream Integrator (DSI), mediates and correlates billing records, whether generated from Sonus-based platforms or from third party application platforms, and incorporates the information into traditional as well as next generation billing systems.

The Sonus billing solution includes a new streaming billing functionality for the GSX4000™ Open Services Switch, which eliminates the need for local storage of billing records by allowing multiple GSX4000s to stream records to a single, centralized DSI Billing System rather then dedicated local servers, driving down the cost of the overall network and maintaining the benefits of a smaller form factor the GSX4000 was designed to address.

Bruce Trvalik, Director, Product Management at Sonus Networks, says, “As for ‘future applications’ it’s very unclear what charging models will be for services as we move forward. A big question concerns whether network operators should replace their existing equipment that’s tied into BSS and OSS, or do they try to play nicely with that equipment? Over the eight years or so that Sonus Networks has been in existence, the preferred idea has been to play nicely with existing equipment. To start with, information must be collected. You have to think about services and what information is ‘traditionally’ billable. For example, Sonus makes gateways and tends to play in the core of operators’ networks, very much in the position where the IMS infrastructure will ultimately live. Early on, we devised a highly distributed architecture. In circuit-switched systems, a customer was not necessarily able to go to one particular box and get all of the relevant information about the network. So, for many years we’ve had to deal with problems similar to the problems faced by IMS.”

“There’s a two-fold challenge here,” says Trvalik. “First is fetching the richness of information that these systems need today, which often means that a lot of that information doesn’t necessarily come from the device itself; e.g., the number of minutes the call has been in progress. All of that information is easy for the device to retrieve. If you look at what’s needed to keep legacy billing systems happy, much of the information they need comes from SS7 signaling. When you look at an IMS architecture or a Sonus architecture, what you’ll see are media gateways, SS7 gateways, and call routing functions. All of these are distributed onto different platforms. To help run all of this as a single system, Sonus years ago acquired a company called Linguatech. A big reason for that acquisition was that the company had some fundamental technology for doing very efficient correlations and aggregations of information. They came up with ideas about how to create rules for collecting distributed information and then processing this into something an upstream system could handle. So, for example, in billing a basic call, our Sonus billing mediation solution, the DataStream Integrator (DSI), will collect information from the appropriate elements. Within that information store, there are correlation keys which allow it to correlate the information from, say, three different elements, which perhaps were involved with the call, and channel that into a single record that can be handled by a traditional billing system.”

“So, we’ve been successful in making these next-gen networks look like a traditional network from back-office perspective,” says Trvalik. “A large part of that was because that’s what existed when we started to company. Some of the newer players had next-gen stuff, but all the big, Tier-1 guys who are our bread and butter had a lot of back office equipment that was accustomed to dealing with circuit-switched devices. These days, the initial step is essentially to take the services coming off of IMS — whether they be voice services or something else — and make them look like a known service from a billing perspective. The challenge appears when, for example, you’re interfacing with a Telcordia system, and the flavor of choice here is a well-known billing system input format, AMA [Automatic Message Accounting] records. Likewise, from a provisioning perspective, many of these systems have no ability to identify endpoints using such things as IP addresses; they only understand phone numbers. So, inasmuch as a service is being delivered to a phone, you can make the legacy systems relatively happy. That’s what we’ve done for years and years.”

“The challenge occurs when you’re billing for services that don’t have phone numbers associated with them,” says Trvalik. “But even if there’s an IP endpoint device, chances are that somewhere it’s mapped out to a phone number and so within this process I’ve described we can provide records in the appropriate format for a legacy billing system. It’s the same story from a provisioning perspective. Massive provisioning systems are very difficult to change, so again, similar services are provisioned by the legacy back office systems. The tricky part comes into play when you want to offer something that can’t be represented by legacy services. Let’s say I’m a wireline guy and now I want to start charging for messaging. I may not have a back office that can deal with that, so the challenge you’re faced with is, when do you finally make a break with the past? Again, if you look at the Tier-1s, quite often they’ll represent something like someone’s street address in 40 different ways. They’re struggling with common representation for very basic information. It’s a tough question as to how you represent these advanced services in systems that were designed to measure metered services; that is, minutes of use. You’ll find that some operators are asking themselves of these other services whether they should stay metered or do they become subscription-based? Certainly the entertainment services quite often are subscription-based. That’s true of some other types of services too. So operators can look at things both ways.”

“One of the most difficult things from an IMS perspective is where you need to have that richness of the legacy billing,” says Trvalik. “It’s not only to satisfy the billing system, but it’s quite often to satisfy regulatory requirements. Operators have obligations and those obligations haven’t necessarily been rewritten for the new IP world yet. For a number of years operators will have to take existing services that are now being sent over an IMS infrastructure, and still provide the richness of the information and the ability to correlate and process it into a format that legacy systems will accept. People certainly don’t want to modify legacy systems to recognize new elements. That’s a more expensive proposition than trying to get the element to play nicely with the legacy system.”

“Moving forward, these systems obviously have to change,” says Trvalik. “It’s almost impossible, I think, to predict how that happens in a generic sense. There really is no standard around the back office, to speak of. Every carrier we deal with has a different mix of systems that is either bought from the vendor community or they built a home-grown system or they’ve got some hybrid monstrosity that draws from both worlds. It’s natural. These systems have grown over many years and they won’t be adapted very easily. You’ll see different ways of billing for some of these services.”

“If you look at the way the IMS standard addresses billing,” says Trvalik, “its designers laid out some basic architecture that we’re all familiar with. It supports the notion of both off-line and on-line charging. Fundamentally, it has something that’s very similar to what we’ve been doing. They’ve defined a collection function and events records with correlation keys. IMS puts a framework in place of how to send DIAMETER-based event records off to a collector and a correlator and things of that nature. Basically, it’s the right approach. However, the information provided is not terribly ‘rich’ today, but I don’t think that was the intent of the IMS architects. People always want IMS to be a ‘cookbook’, but it’s actually an architecture. So there’s still work to be done on the IMS standards’ billing front. On-line charging will be a bit more difficult than today because of the real-time nature of what’s happening in the system. It will be interesting to see what the typical back office can do with real-time, service-based information, since I’d don’t think most major operators are set up to do that today.”

Trvalik elaborates: “Case in point: I went to check my minutes of use on my mobile phone. The figure for my voice minutes are usually up to snuff and the figure for my data minutes are usually about a week out of synchronization. Many of the data services don’t even have facilities to really collect the data in any reasonably accurate way and get it to a Web portal, which is funny because you’d think the data guys would have a much easier job than the voice guys. But again, it all goes back to the newness of the services for many of these operators and the way they charge for them.”

Because of the size and depth of Zippy’s article, readers can peruse this feature in its entirety below.

Richard Grigonis is Executive Editor of TMC’s IP Communications Group.


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