George Clapp

Architectures and Protocols for Capacity Efficient, Highly Dynamic and Highly Resilient Core Networks [Invited]

The Core Optical Networks (CORONET) program addresses the development of architectures, protocols, and network control and management to support the future advanced requirements of both commercial and government networks, with a focus on highly dynamic and highly resilient multi-terabit core networks. CORONET encompasses a global network supporting a combination of IP and wavelength services. Satisfying the aggressive requirements of the program required a comprehensive approach addressing connection setup, restoration, quality of service, network design, and nodal architecture. This paper addresses the major innovations developed in Phase 1 of the program by the team led by Telcordia and AT&T. The ultimate goal is to transfer the technology to commercial and government networks for deployment in the next few years.

Optical dynamic circuit services

IP service, leased-line service and POTS service have been the three long-standing communication service offerings of providers. Recently, both commercial and research-and-education network providers have started offering optical dynamic circuit services. This article reviews these services, differentiates DCS from leased-line services, offers a classification of DCS, and proposes two new types of DCS. DCS are classified into two types: Specified-Duration Scheduled and Unspecified-Duration Unscheduled. SDS service is less flexible than UDU service in that it requires users to specify call durations, and is more complex (needs reservation schedulers), but it is the only efficient option if link bandwidth is divided into a small number of channels (e.g., 1 Gb/s circuits on a 10 Gb/s link for fast transfers of large files). For SDS offerings, if the mean call duration is small, then a distributed scheduler implementation may be required to handle the high call arrival load required to maintain high utilization levels. Finally, SDS is classified into two sub-types: Specified Start Time and Earliest Start Time, based on whether the user can only accept a start time from within its own specified set of start times, or whether it can accept any, preferably earliest, start time. The SST sub-type is useful for applications requiring the co-scheduling of network bandwidth with other resources, while the EST sub-type is ideal for file transfers.

Management of switched systems at 100 Tbps: The DARPA CORONET program

The DARPA CORONET program is laying the foundations for a next generation IP-over-Optical network that supports 100 Tbps of traffic and provides rapid, on-demand, switched wavelength services. The wavelength services are very dynamic, with setup times of 100 ms and holding times as short as a few seconds to a minute. A major management challenge is designing a provisioning protocol for the dynamic services. We describe in this paper a 3-Way Handshake (3WHS) protocol that meets the service requirements, and we provide simulation results of the performance of the 3WHS.

Lessons learned from CORONET

The DARPA CORONET Program is focused on multi-terabit core optical networks supporting highly dynamic IP and wavelength services. We describe key methodologies for achieving CORONET objectives and insight into important elements for future commercial applicability.

Metro network design methodologies that build a next-generation network infrastructure based on this generation's services and demands

This paper describes two key network architecture design concepts that relate to evolving existing transport networks into economically viable next-generation optical networks. Todays metropolitan transport networks largely consist of synchronous optical network/synchronous digital hierarchy rings or switch-to-switch fiber connections for some form of optical Ethernet. The result is an optical-electrical-optical infrastructure that has limited use in providing wavelength services. Wavelength-division multiplexing (WDM) is the enabling technology for wavelength services, but it has limited penetration in the metropolitan area due to its cost justification being dependent primarily on fiber relief. The first part of this paper shows how existing services, primarily using time-division-multiplexing (TDM) transport, can be used to economically justify a WDM infrastructure while achieving significantly lower costs than legacy design techniques would produce. Dynamic bandwidth-on-demand (BoD) service is another elusive goal envisioned for next-generation metropolitan networks. This paper addresses how an economically viable BoD infrastructure can be built based on revenues from existing enterprise services rather than relying on revenues from new and unproven services. Quantitative analyses, presented in the paper, show the key parameters that determine when BoD services will be used, how bandwidth granularity affects BoD decisions, and how the customers use of BoD drives service provider network design considerations.

Performance of IP over optical networks with dynamic bandwidth allocation

IP over optical network performance can be improved with dynamic bandwidth allocation, depending on the reallocation paradigm and the network topology. Under high connectivity, dynamic bandwidth allocation provides a notable boost to the networks traffic-carrying capacity.

Architectures and protocols for highly dynamic IP-over-Optical networks

The DARPA CORONET program is laying the foundations for a next generation IP-over-Optical network that supports 100 Tbps of traffic and provides rapid, on-demand, switched wavelength services. The wavelength services are very dynamic, with setup times of 100 ms and holding times as short as a few seconds to a minute. A major management challenge is designing a provisioning protocol for the dynamic services. We describe in this paper a 3-Way Handshake (3WHS) protocol that meets the service requirements, and we provide simulation results of the performance of the 3WHS.

Data in the optical domain technology: A network-level perspective

This study focuses on network-level issues that fall into three broad categories: 1) network performance, 2) network requirements and 3) drivers and applications for the DOD-N. The goal of this work is to investigate the value, viability, and fit of this new networking technology across a broad spectrum of network scenarios. A network simulation environment is constructed, which allows the investigation of the performance of DOD-networks as a function of node design and technologies, network architecture, network scale, traffic characteristics, physical layer constraints, and other parameters. The intent of Telcordias project is to bring network-level issues to bear to optimize both the performance and the utility of the DOD-N technologies.

Requirements and design of a dynamic Grid networking layer

We address the requirements and design of bandwidth on demand networks in the context of Grid services. Regardless of the deployment scenario for Grid services (e.g., commercial or research), there is a need for efficient use of network facilities and a need to meet the performance requirements of the Grid services users. We present quantitative analysis showing how these needs can be met.

The Flexible, Dynamic Optical Layer: Myths and Realities

A dynamic optical network that adjusts quickly and automatically to changes in offered traffic load provides performance superior to that of a network of fixed, static optical connections only under certain conditions: a high degree of interconnectivity among the network nodes and a moderate granularity of traffic relative to link capacity.