ATM forum pres. talks it up

George Dobrowski, president of the ATM Forum, last week in Atlanta sat down with Network World's Associate News Editor Michael Cooney and Senior Editor Denise Pappalardo to discuss the forum's focus on IP and ATM interoperability.

Would you say there is more of a concerted effort within the ATM Forum to ensure IP and ATM technologies work better together in the future?

IP and ATM interworking is a clear focus of the forum. And there are a number of efforts that have been underway for a while - LAN Emulation and Multi-Protocol over ATM to name a couple - that have always had at their core IP capabilities.

We are also working on new IP/ATM-related specifications, such as Guaranteed Frame Rate and Private Network-to-Network Interface Augmented Routing (see story, page 1), that should help better support IP in ATM environments. We are working with the Internet Engineering Task Force to ensure developing IP standards, such as Multi-protocol Label Switching, Differentiated Services and others, will work with ATM standards smoothly.

How is the ATM Forum working with the IETF on quality-of-service (QoS) issues?

This is the first ATM Forum meeting with technical contributions from the IETF's Differentiated Services group. We are working on how to map the IETF's efforts back to ATM. The Differentiated Services group does not define the parameters that make up the various classes of service on a network, but Diff-Serv does state how to mark packets with a priority status. We are looking at how Diff-Serv and ATM can work together to deliver end-to-end QoS.

Why IP and ATM, though? What are the benefits of tightly coupling those technologies?

No doubt that IP is the sexy technology. As bandwidth needs go up, so does the need for ATM and ATM's QoS capabilities. IP has more challenges ahead of it than ATM does, especially when it comes to adding QoS. That's not to say we don't have some things to work out with ATM, but certainly ATM has a lot of technology that the IP community could use. We want to make sure that IP can move into the realm of real-time QoS.

What is the forum doing to ensure voice traffic will be supported across IP backbones?

The International Telecommunication Union, the IETF and the ATM Forum have all come together to ensure we are all working with the same version of H.323, which is the ITU's specification for voice and video support over IP.

Because there are now three version of H.323, it's important to agree on one version that will optimize voice support over IP and ATM.