Mike, a very good article about programmable switches in
internettelephony.com
Here is a clip,no URL.
Architecture plans differ
Programmable switch vendors may be driving in the same direction, but they're taking different roads. While Nortel is building on its core platform, Summa Four and Excel are evolving their platforms in opposite directions with regard to architecture.
Excel is embracing a distributed architecture with its Open Network Expansion architecture platform (Figure 2). It uses Excel's Expandable Switching System hardware and software and Excel's patented Programmable Protocol Language to allow carriers to build a distributed switching architecture that is open to integrate unrelated resources, such as interactive voice response, voice recognition and voice-over-Internet devices, into the switch. The system is designed to work with any host platform, and applications can be written independent of the network protocol. The system also allows for new technologies to be incorporated via daughter card processors, eliminating the need for system redesigns for such implementations.
"Our story of openness applies to every piece in the architecture, and it's not just programmability," Foster says. "Operators can change the software that runs the switch itself. As we move more and more into the network, ONE architecture allows us to provide network routing and management services required in the network infrastructure environment. We can now position ourselves as not just a programmable switch. Very often, we're seeing ourselves being compared with traditional switches."
With its new architecture, Excel plans to offer a platform that can support small carriers' needs and grow to a very high density.
"[Customers] can purchase as few as a couple hundred ports and grow to meet capacity requirements up to 30,000 ports in a single switch," Foster says.
While Excel's thrust is for a distributed architecture, Summa Four is developing an integrated programmable switch with its Project Sigma initiative. The idea is to integrate the switch, the media (the elements that provide various capabilities such as voice, fax, speech recognition and voice/fax over IP) and the host into a single box (Figure 3).
The project is still being developed, but Summa Four has already clearly defined how the system will work. It will consist of three products: a media server designed to meet intelligent peripheral requirements; a voice-over-IP gateway that supports up to 2000 fully redundant voice-over-IP connections and a variety of compression algorithms for voice and fax; and a transport platform that scales up to 16,000 non-blocking ports and is designed for use as a programmable Class 4 or 5 switch or, for wireless, a base station controller, mobile switching center or wireless local loop controller.
"Media and switching are now fully integrated," Carlino says. "You can move calls around and provide all the services you need. It's a core switching platform suitable for CO deployment."
The intended small footprint for the Project Sigma devices should make it appealing in terms of real estate costs as well as its lower initial cost to deploy. By reducing the space a single platform requires, carriers can scale their switching centers to greater densities without having to expand their actual floor space to do so. Those factors should be especially appealing to newer carriers that are just building their networks, and a network starting from scratch is an ideal opportunity for programmable switches to make inroads, Carlino says.
"Newer networks aren't tied to [legacy equipment] constraints," he says. "It allows them to build intelligence from the start and to be scalable."
Changing with the times
With all the new competition cropping up, established carriers are beginning to change their thinking to match that of their new competitors, says Alex McCarthy, business manager of telco network services at Dialogic, which makes media for programmable switches and has worked closely with Summa Four on Project Sigma.
"A lot of Bell [companies] are setting up internally and behaving entrepreneurially," McCarthy says.
Part of that entrepreneurial behavior involves offering new services to customers. However, offering a new service doesn't guarantee success. Different areas of the same city may have different demands for services. Business districts and residential areas are evidence of that. The question for carriers becomes one of determining what services will do well in which areas.
Nortel's Doerk says that integrating the programmable switching functions into a primary switch allows carriers greater flexibility in trying out new services.
"A number of enhanced services have different busy hours," Doerk says. "Very often, carriers have excess capacity on certain trunks. At a cost much lower than a third-party programmable switch, [carriers] can have programmable switch functionality, and they don't have to add hardware or trunk capacity to try an enhanced service. If it takes off, they can add additional resources to handle demand. If not, they can move on to the next enhanced service."
As programmable switches become more important to network operators, the switches themselves will have to evolve, as will the vendors and their strategies. The programmable switches enjoy several key competitive points. They include providing the same capabilities and reliability that current CO switches provide, as well as supporting industry standards such as ATM, frame relay and eventually, voice over IP. But the crucial element is building programmable switching into a standards-based function.
"The future for programmable switching lies in being established as a valid, standard architecture for switching in the future," Excel's Foster says. "We want to build awareness of programmable switching and have standards for the future."
As such standards evolve, it will become easier for more companies to write applications for programmable switches, leaving carriers in an interesting quandary, says The Yankee Group's Rich. The more applications vendors there are, the more difficult it will be to separate the wheat from the chaff.
"It ultimately opens up to a much larger group of applications developers," Rich says. "Having it open to more [programmers] gives more choice and you probably pay a little bit less, but [carriers] obviously don't want any Tom, Dick or Harry who's a Unix hack" writing applications for their switches.
But, as Dataquest's Kelly points out, those days are still far away. Despite the advances in programmable switching, such devices aren't ready to take over for the bigger switches, and will remain still in a specialized--if slightly more expanded--role, he says.
"They're lacking the services to use as a core switching system. The feature content in big switches is humongous," Kelly says. "The good news is, one size doesn't have to fit all. They can be used in rural areas where you don't need a ubiquitous switch."
It is clear that while programmable switches will continue to grow in importance, the growth curve will be shallow. Open programmability may become a more common feature among switch vendors, but an absolute change to programmable switches is not going to happen in the foreseeable future.
"There's no one type of switch that's going to win out," says Mine. "CLECs are increasing demand for smaller, more flexible platforms, but there will be continued demand for large-scale networks."
Programmable switch vendors agree. Despite the company's belief that its platform is a viable stand-alone switch, Summa Four's Carlino says the company doesn't expect its switches' roles to entirely change from service-provisioning adjuncts to CO anchors.
"It's a dual role," Carlino says. "We continue to see growth on both sides."
got to go to work,
Hiram |
