Chin Guok

Chin P. Guok
Network Engineer
Network Engineering Services Group

Chin Guok joined ESnet in 1997 as a network engineer, focusing primarily on network statistics. He was a core engineer in the testing and production deployment of MPLS and QoS (Scavenger Service) within ESnet.  He is the technical lead of the ESnet On-demand Secure Circuits and Advanced Reservation System (OSCARS) project which enables end-users to provision guaranteed bandwidth virtual circuits within ESnet. He also serves as a co-chair of the Open Grid Forum On-Demand Infrastructure Service Provisioning Working Group.

His research interests include high-performance networking and network protocols; dynamic network resource provisioning; network tuning issues; hybrid network traffic engineering. Guok received a M.S. in Computer Science, from the University of Arizona in 1997 and a B.S. Computer Science, University of Pacific in 1991.


Journal Articles

Z. Yan, M. Veeraraghavan, C. Tracy, C. Guok, “On How to Provision Virtual Circuits for Network-Redirected Large-Sized, High-Rate Flows”, International Journal on Advances in Internet Technology, vol. 6, no. 3 & 4, 2013, November 1, 2013,

Tom Lehman, Xi Yang, Nasir Ghani, Feng Gu, Chin Guok, Inder Monga, and Brian Tierney, “Multilayer Networks: An Architecture Framework”, IEEE Communications Magazine, May 9, 2011,

Neal Charbonneau, Vinod M. Vokkarane, Chin Guok, Inder Monga, “Advance Reservation Frameworks in Hybrid IP-WDM Networks”, IEEE Communications Magazine, May 9, 2011, 59, Issu:132-139,

Inder Monga, Chin Guok, William E. Johnston, and Brian Tierney, “Hybrid Networks: Lessons Learned and Future Challenges Based on ESnet4 Experience”, IEEE Communications Magazine, May 1, 2011,

Chin P. Guok, Jason R. Lee, Karlo Berket, “Improving The Bulk Data Transfer Experience”, International Journal of Internet Protocol Technology 2008 - Vol. 3, No.1 pp. 46 - 53, January 1, 2008,

“Measurements On Hybrid Dedicated Bandwidth Connections”, INFOCOM 2007, IEEE (TCHSN/ONTC), May 1, 2007,


Conference Papers

M Kiran, E Pouyoul, A Mercian, B Tierney, C Guok, I Monga, “Enabling Intent to Configure Scientific Networks for High Performance Demands”, 3nd International Workshop on Innovating the Network for Data Intensive Science (INDIS) 2016, SC16., November 10, 2016,

Henrique Rodriguez, Inder Monga, Abhinava Sadasivarao , Sharfuddin Sayed, Chin Guok, Eric Pouyoul, Chris Liou,Tajana Rosing, “Traffic Optimization in Multi-Layered WANs using SDN”, 22nd Annual Symposium on High-Performance Interconnects, Best Student Paper Award, August 27, 2014,

Wide area networks (WAN) forward traffic through a mix of packet and optical data planes, composed by a variety of devices from different vendors. Multiple forwarding technologies and encapsulation methods are used for each data plane (e.g. IP, MPLS, ATM, SONET, Wavelength Switching). Despite standards defined, the control planes of these devices are usually not interoperable, and different technologies are used to manage each forwarding segment independently (e.g. OpenFlow, TL-1, GMPLS). The result is lack of coordination between layers and inefficient resource usage. In this paper we discuss the design and implementation of a system that uses unmodified OpenFlow to optimize network utilization across layers, enabling practical bandwidth virtualization. We discuss strategies for scalable traffic monitoring and to minimize losses on route updates across layers. We explore two use cases that benefit from multi-layer bandwidth on demand provisioning. A prototype of the system was built open using a traditional circuit reservation application and an unmodified SDN controller, and its evaluation was per-formed on a multi-vendor testbed.



Abhinava Sadasivarao, Sharfuddin Syed, Chris Liou, Ping Pan, Andrew Lake, Chin Guok, Inder Monga, “Open Transport Switch - A Software Defined Networking Architecture for Transport Networks”, August 17, 2013,


There have been a lot of proposals to unify the control and management of packet and circuit networks but none have been deployed widely. In this paper, we propose a sim- ple programmable architecture that abstracts a core transport node into a programmable virtual switch, that meshes well with the software-defined network paradigm while leverag- ing the OpenFlow protocol for control. A demonstration use-case of an OpenFlow-enabled optical virtual switch im- plementation managing a small optical transport network for big-data applications is described. With appropriate exten- sions to OpenFlow, we discuss how the programmability and flexibility SDN brings to packet-optical backbone networks will be substantial in solving some of the complex multi- vendor, multi-layer, multi-domain issues service providers face today. 


Z. Yan, M. Veeraraghavan, C. Tracy, and C. Guok, “On how to Provision Quality of Service (QoS) for Large Dataset Transfers”, Proceedings of the Sixth International Conference on Communication Theory, Reliability, and Quality of Service, April 21, 2013,

Inder Monga, Eric Pouyoul, Chin Guok, “Software Defined Networking for big-data science (paper)”, SuperComputing 2012, November 11, 2012,


University campuses, Supercomputer centers and R&E networks are challenged to architect, build and support IT infrastructure to deal effectively with the data deluge facing most science disciplines. Hybrid network architecture, multi-domain bandwidth reservations, performance monitoring and GLIF Open Lightpath Exchanges (GOLE) are examples of network architectures that have been proposed, championed and implemented successfully to meet the needs of science. Most recently, Science DMZ, a campus design pattern that bypasses traditional performance hotspots in typical campus network implementation, has been gaining momentum. In this paper and corresponding demonstration, we build upon the SC11 SCinet Research Sandbox demonstrator with Software-Defined networking to explore new architectural approaches. A virtual switch network abstraction is explored, that when combined with software-defined networking concepts provides the science users a simple, adaptable network framework to meet their upcoming application requirements. 


Tom Lehman , Xi Yang, Chin P. Guok, Nageswara S. V. Rao, Andy Lake, John Vollbrecht, Nasir Ghani, “Control Plane Architecture and Design Considerations for Multi-Service, Multi-Layer, Multi-Domain Hybrid Networks”, INFOCOM 2007, IEEE (TCHSN/ONTC), May 1, 2007,

Chin Guok, David Robertson, Mary Thompson, Jason Lee, Brian Tierney and William Johnston, “Intra and Interdomain Circuit Provisioning Using the OSCARS Reservation System”, Third International Conference on Broadband Communications Networks, and Systems, IEEE/ICST, October 1, 2006,

Book Chapters

William Johnston, Evangelos Chaniotakis, Eli Dart, Chin Guok, Joe Metzger, Brian Tierney, “The Evolution of Research and Education Networks and their Essential Role in Modern Science”, Trends in High Performance & Large Scale Computing, ( November 1, 2008)

Published in: "Trends in High Performance & Large Scale Computing" Lucio Grandinetti and Gerhard Joubert, Editors


Inder Monga, Chin Guok, SDN for End-to-End Networking at Exascale, February 16, 2016,

Traditionally, WAN and campus networks and services have evolved independently from each other. For example, MPLS traffic engineered and VPN technologies have been targeted towards the WAN, while the LAN (or last mile) implementations have not incorporated that functionality. These restrictions have resulted in dissonance in services offered in the WAN vs. the LAN. While OSCARS/NSI virtual circuits are widely deployed in the WAN, they typically only run from site boundary to site boundary, and require painful phone calls, manual configuration, and resource allocation decisions for last mile extension. Such inconsistencies in campus infrastructures, all the way from the campus edge to the data-transfer hosts, often lead to unpredictable application performance. New architectures such as the Science DMZ have been successful in simplifying the variance, but the Science DMZ is not designed or able to solve the end-to-end orchestration problem. With the advent of SDN, the R&E community has an opportunity to genuinely orchestrate end-to-end services - and not just from a network perspective, but also from an end-host perspective. In addition, with SDN, the opportunity exists to create a broader set of custom intelligent services that are targeted towards specific science application use-cases. This proposal describes an advanced deployment of SDN equipment and creation of a comprehensive SDN software platform that will help with bring together the missing end-to-end story. 

Abhinava Sadasivarao, Sharfuddin Syed, Ping Pan, Chris Liou, Andy Lake, Chin Guok, Inder Monga, Open Transport Switch: A Software Defined Networking Architecture for Transport Networks, Workshop, August 16, 2013,

Presentation at HotSDN Workshop as part of SIGCOMM 2013

M. Boddie, T. Entel, C. Guok, A. Lake, J. Plante, E. Pouyoul, B. H. Ramaprasad, B. Tierney, J. Triay, V. M. Vokkarane, On Extending ESnet's OSCARS with a Multi-Domain Anycast Service, IEEE ONDM 2012, December 2012,

I. Monga, E. Pouyoul, C. Guok, Software-Define Networking for Big-Data Science – Arthictectural Models from Campus to the WAN, SC12: IEEE HPC, November 2012,

C.Guok, E, Chaniotakis, A. Lake, OSCARS Production Deployment Experiences, GLIF NSI Operationalization Meeting, October 2012,

C. Guok, I. Monga, IDCP and NSI: Lessons Learned, Deployments and Gap Analysis, OGF 34, March 2012,

T. Lehman, C. Guok, Advanced Resource Computation for Hybrid Service and TOpology Networks (ARCHSTONE), DOE ASCR PI Meeting, March 2012,

Chin Guok, Evolution of OSCARS, Joint Techs, January 23, 2012,

On-demand Secure Circuits and Advance Reservation System (OSCARS) has evolved tremendously since its conception as a DOE funded project to ESnet back in 2004. Since then, it has grown from a research project to a collaborative open-source software project with production deployments in several R&E networks including ESnet and Internet2. In the latest release of OSCARS as version 0.6, the software was redesigned to flexibly accommodate both research and production needs. It is being used currently by several research projects to study path computation algorithms, and demonstrate multi-layer circuit management. Just recently, OSCARS 0.6 was leveraged to support production level bandwidth management in the ESnet ANI 100G prototype network, SCinet at SC11 in Seattle, and the Internet2 DYNES project. This presentation will highlight the evolution of OSCARS, activities surrounding OSCARS v0.6 and lessons learned, and share with the community the roadmap for future development that will be discussed within the open-source collaboration.

C. Guok, OSCARS, GENI Project Office Meeting, May 2011,

W.E. Johnston, C. Guok, J. Metzger, B. Tierney, Network Services for High Performance Distributed Computing and Data Management, The Second International Conference on Parallel, Distributed, Grid, and Cloud Computing for Engineering, Ajaccio - Corsica - France, April 12, 2011,

Chaitanya S. K. Vadrevu, Massimo Tornatore, Chin P. Guok, Inder Monga, A Heuristic for Combined Protection of IP Services and Wavelength Services in Optical WDM Networks, IEEE ANTS 2010, December 2010,

C. Guok, OSCARS Roadmap, OGF 28; DICE Control Plane WG, May 2010,

C. Guok, I. Monga, Composible Network Service Framework, ESCC, February 2010,

C. Guok, ESnet OSCARS, DOE Joint Engineering Taskforce, February 2009,

Chin Guok, David Robertson, Evangelos Chaniotakis, Mary Thompson, William Johnston, Brian Tierney, A User Driven Dynamic Circuit Network Implementation, IEEE DANMS 2008, November 2008,

C. Guok, Impact of ESnet OSCARS and Collaborative Projects, SC07, November 2007,

ESnet On-demand Secure Circuits and Advance Reservation System (OSCARS), Google invited talk; Advanced Networking for Distributed Petascale Science Workshop; IEEE GridNets; QUILT Fall Fiber Workshop, 2008, 2006,