Stephen S. Liu

A model and evaluation of distributed network management approaches

This paper develops an analytical framework to model and compare centralized and distributed approaches for network management. Each scheme is evaluated in terms of performance and scalability for two applications, network monitoring, and data searching. The results support the intuitive argument that distributed approaches can have considerable advantages over traditional centralized network management, but a single approach may not be best for all types of applications. Instead, the most appropriate approach for a specific application should be selected after a careful evaluation. The modeling framework presented is intended to quantify the tradeoffs between different approaches to lend a basis for the selection decision.

Deployment of Carrier-Grade Bandwidth-on-Demand Services over Optical Transport Networks: A Verizon Experience

In September 2006, Verizon partner solutions (VPS) launched the bandwidth-on-demand (BoD) service trial in New York City, as a precursor to the formal rollout of just-in-time provisioning (JiT) service in 2007. The JiT service will offer wholesale customers OC-n, Ethernet private line, and DS3 services utilizing a GMPLS-based intelligent optical network to reduce provisioning intervals. This paper presents Verizons experience in deploying BoD/JiT Provisioning services, and identifies technology gaps and operations challenges.

Verizon experience with NG Ethernet services: evolution to a converged layer 1, 2 network

This article presents Verizons experience with deploying metro Ethernet services and some of our laboratory activities related to the convergence of layer 2/1 networks. Such convergence leverages the existing SONET and optical transport network infrastructure, and integrates layer 1 and layer 2 transport, control, and management planes within the network. Integrated service provisioning is featured, including service logic and policy that controls the admission, path selection, and transport bandwidth adjustment requirements of provisioning an Ethernet virtual connection within the metro Ethernet network.

Protection switching performance in next generation optical transport networks

Sub-50 millisecond protection switching times are embedded in the requirements, tariffs, and practices of carriers such as Verizon. This paper reports on a recent Verizon study of next generation optical transport gear that implements shared mesh protection schemes. We find that such schemes most likely will not perform protection switching in less than 50 milliseconds for even moderate numbers of paths. This paper explains our methodology and findings.

Demonstration of multivendor E-NNI interoperability across a 1000 km production network

E-NNI allows network to network interconnection between multiple vendors and I-NNI domains in an ASON/GMPLS network. Verizon and participating vendors have demonstrated end-to-end STS-n circuit provisioning across 1000 km in a production network.