NTT Research and Development 2008 Review of Activities

The spread of broadband Internet communications is causing a significant shift in the ways networks are used. For example, clients are increasingly exchanging large files such as video content, and many corporate and individual clients are getting into the habit of engaging in simultaneous communication.

To implement communication systems that are better able to reflect the state of end-to-end network usage while continuing to provide the same quality of service to clients, the routing of information (traffic) through the network must be continuously optimized. However, performing this task with the routers and optical transmission equipment that has conventionally been used on the Internet gives rise to issues from the viewpoint of the flexibility of computation algorithms and computational capacity, and issues associated with the difficulty of ascertaining the network status between multiple service providers and across different layers.

At NTT Laboratories, to separate these traffic engineering functions from the communication equipment itself, we have been working on the standardization of PCE^*1 architecture and the standardization based on the PCEP^*2 of interfaces between PCEs and communication systems. Our proposals have now been incorporated as the basis of international standards on architecture and interface (protocol). At the same time, we have developed protocol software based on these standards.

We have confirmed that this technology is able to control existing optical communication equipment and routers, thereby allowing paths to be optimized across multiple administrative regions (which is normally very difficult to achieve). In addition to the standardization efforts, there have also been international developments of software products, and it is reported that as of March 2008 this software has been implemented by 9 companies including NTT Advanced Technology Corporation^*3.

At NTT Laboratories, we are expanding and developing this technology while continuing with our standardization efforts, which include optimizing the path computation algorithms used between multiple services and different communication technologies (e.g., optical networks and IP networks), taking the characteristics of optical communication more strictly into consideration, and dealing with connections among multiple locations. We are also conducting research and development to support further development of our broadband services with a view to implementing networks that provide our customers with optimal quality at all times.

• *1 PCE: Path Computation Element
• *2 PCEP: Path Computation Element communication Protocol
• *3 NTT Advanced Technology Corporation news release, December 18, 2007