Dynamic desires

Finding a middle ground in technology can be a daunting task, but some vendors are attempting it as they try to usher in Internet protocol. With the dependability of circuit-switched networks and the flexibility and scalability of packet networks, a bridge between the two could prove attractive.

Dynarc, based in Sweden, is hoping to provide that bridge between circuit and packet networks with its dynamic synchronous transfer mode (DTM) technology.

The technology, which operates on a multiservice switch and a port adapter, uses dynamic circuit-oriented switching and transmission architecture to replace and fill in gaps that other platforms such as asynchronous transfer mode and Sonet leave.

DTM meets the scalability and quality of service needs necessary for data-centric networks, said Per Lembre, product manager for Dynarc. "The technology provides a flexible and scalable link layer and more simple circuit switching." Dynarc is applying that simplicity to its metropolitan area network switches.

"Metropolitan customers want a reliable platform that is simple to manage," said Lembre. Because DTM can run over existing infrastructure, that simplicity and cost-effectiveness is increased, he said.

"There are a lot of carriers looking to build out their local access rings, and they are looking for very flexible, very cost-effective technology to do it," said Joe Skorupa, director of switching and routing for RHK. Dynarc believes DTM will be substantially less expensive to implement, and if the company can drive down the equipment cost, opportunities will develop with small carriers, he said.

"At Supercomm, we will demonstrate even greater flexibility of DTM by running it over Sonet and [wave division multiplexing]," added Lembre. Carriers also can have the benefits of flexible bandwidth with the product, Lembre said.

DTM is more like time division multiplexing (TDM) than ATM. It incorporates many benefits of ATM, but accomplishes them from a TDM perspective, said Christine Flynn, analyst with The Yankee Group.

So does DTM win out over ATM? Flynn believes it has significant advantages but lacks market acceptance. "Seeing that it is a complicated technology, as ATM is, it will take time to be accepted," she said.

Skorupa agrees, but notes some hurdles. For example, although DTM fits well into the metro space, Dynarc has focused primarily on the technology and still has to address the software side, such as network management and operational issues, said Skorupa. "Can they get the product out the door, can they get it into trials, and can they get some high-profile wins?" asked Skorupa. "If you want to make it here you have to get into a Qwest or a Level 3 or Williams."

That is where Cisco Systems is jumping on the dynamic path, with its dynamic packet transport products, which are also targeted at the metropolitan environment. Cisco's connectionless technology focuses on packet data rather than multiservices. The company has the added benefit of current trials at Qwest and at Sprint.

Skorupa and Flynn still consider DTM a better technology. In fact, Cisco's entrance in the market validates Dynarc's activities, Flynn said. Dynarc's DTM has advantages over the Cisco product because it can support telephony, circuit and packet data, making it much more flexible, added Skorupa. Dynarc's product is at least as good, if not better, than Cisco's metro product, he said.

Unlike Cisco, Dynarc is willing to license the technology to other vendors. That could propel DTM in the marketplace, despite Cisco's dominant presence.

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