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Time-driven or Fractional Lambda Switching for "Green Internet"

Ultra scalable UTC-based pipeline switching and forwarding for IP packet flows, while:
- Providing "Green Internet" solution by significantly reducing the required electricity for switching in the core, metro and access networks, while fully utilizing the link capacity
- solving switch and link bottlenecks
- providing quality of service guarantees for all streaming media applications
- enabling high-speed, predictable and efficient transfer of very large files for GRID and database applications

This architecture can be realized in the all optical domain with minimum buffering and optimal non-blocking switching complexity, with scalability to 10-100 Tb/s in a single chassis.
Nguyen V. T., Lo Cigno R. A., Ofek Y., Telek M., "Time Blocking Analysis in Time-driven Switching Networks". In: proc. IEEE INFOCOM 2008 , Usa:IEEE/INFOCOM 2008, 2008. Atti del convegno: "INFOCOM 2008", Phoenix , AZ, USA, April 15-17 2008
Nguyen V. T., Lo Cigno R. A., Ofek Y., "Tunable Laser-based Design and Analysis for Fractional Lambda Switches". IEEE transactions on communications, 2008, v. 56, n. 6, p. 957-967. , DOI: 10.1109/TCOMM.2008.060707
Mario Baldi, Guido Marchetto, Yoram Ofek, “A scalable solution for engineering streaming traffic in the future Internet,” Computer Networks: The International Journal of Computer and Telecommunications Networking, Volume 51 Issue 14, October 2007, Elsevier North-Holland, Inc.
O. Zadedyurina , Y. Ofek, A.Pattavina “Space and Time Blocking versus Cost in all optical Banyan Networks”, ICC2008 International Conference on Communications in Beijing, May 2008
D. Agrawal , M. Baldi , M. Corrà, G. Fontana, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina, T. H. Truong, O. Zadedyurina “A Scalable Approach for Supporting Streaming Media: Design, Implementation and Experiments”, 12th IEEE Symposium on Computers and Communications, July 2007, Portugal
D. Agrawal , M. Baldi , M. Corrà, G. Fontana, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina, T. H. Truong, O. Zadedyurina “Scalable Switching Testbed not “Stopping” the Serial Bit Stream”, ICC 2007 Optical Networks and Systems Symposium, Glasgow, Scotland, UK
Thu-Huong Truong, Mario Baldi, Yoram Ofek “Scheduling High-Rate Sessions in Fractional Lambda Switching Networks: Algorithm and Analysis,” ISCC, Morocco, June 2008.
Thu-Huong Truong, Mario Baldi, Yoram Ofek, “Efficient Scheduling for Heterogeneous Fractional Lambda Switching Networks”, IEEE Globecom 2007, Washington DC, USA.
D. Agrawal, M. Baldi, M. Corra, G. Fontana, T. H. Truong, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina, O. Zadedyurina, "Multi-terabit per Second Scalable Switch Prototype," Technical Report, Internal Publication, January 2006. http://dit.unitn.it/ipflow/tech-rep.html
D. Agrawal, M. Baldi, M. Corra, G. Fontana, T.T. Huong, G. Marchetto, V.T. Nguyen, Y. Ofek, D. Severina, and O. Zadedyurina, "Global Time from GALILEO for Overcoming Internet Challenges: Switching Scalability and Streaming Media," Parliament Magazine, 20 March 2006.
Mario Baldi and Yoram Ofek, "Lambda and Sub-lambda Switching", in The Handbook of Computer Netwroks, Hossein Bidgoli (Editor), John Wiley & Sons, 2006.
T. H. Truong, M. Baldi, Y. Ofek, "An Efficient Scheduling Algorithm for Time-Driven Switching Networks," LANMAN 07, The 15th IEEE workshop on Local and Metropolitan Area Networks, Pricenton, New Jersey, USA
L. Gasparini, O. Zadedyurina, G. Fontana, D. Macii, A. Boni, Y. Ofek, "An Effective Digital Circuit for Jitter Reduction of GPS Synchronization Signals," AMUEM '07- IEEE International Workshop on Advanced Methods for Uncertainty Estimation in Measurement 2007, Sardagna, Trento, Italy, July 16-18 2007.
D. Agrawal, M. Baldi, M. Corr�, G. Fontana, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina, T. H. Truong, O. Zadedyurina, "A Scalable Approach for Supporting Streaming Media: Design, Implementation and Experiments," ISCC 2007 - IEEE Symposium on Computers and Communications, Aveiro, Portugal, 1-4 July 2007.
D. Agrawal, M. Baldi, M. Corr�, G. Fontana, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina, T. H. Truong, O. Zadedyurina, "Scalable Switching Testbed not "Stopping" the Serial Bit Stream," ICC 2007 - The IEEE International Conference on Communications 2007, Glasgow, Scotland, 24-28 June 2007.
V.T. Nguyen, R. Lo Cigno, Y. Ofek, "Blocking Analysis of Time-Driven Switching".
Deepak Agrawal, Michele Corra, Viet Thang Nguyen, and Yoram Ofek, "UTC based Controller for Scalable Time Driven Switching", IEEE Globecom 2006, San Francisco, USA, Nov 27, Dec 01, 2006.
D. Agrawal, M. Baldi, M. Corra, G. Fontana, T. H. Truong, G. Marchetto, V. T. Nguyen, Y. Ofek, D. Severina and O. Zadedyurina, "Ultra Scalable UTC-based Pipeline Forwarding Switch for Streaming IP Traffic", IEEE International Conference on Computer Communications (Infocom), Barcelona, Spain, April 23-29, 2006, Poster/Demonstration.
V. T. Nguyen, R. Lo Cigno , Y. Ofek, "Design and Analysis of Tunable Laser-based Fractional Lambda Switching (FLS)," IEEE INFOCOM 2006. (Abstract)
Y. Ofek, "Ultra Scalable Optoelectronic Switching Fabric for Streaming Media over IP," ISSPIT 2005 (IEEE International Symposium on Signal Processing and Information Technology). (Abstract)
Donato Grieco, Achille Pattavina and Yoram Ofek, "Fractional lambda switching for flexible bandwidth provisioning in wdm networks: principles and performance," Photonic Network Communications, Issue: Volume 9, Number 3, Date: May 2005, Pages: 281 � 296. (Abstract)
M. Baldi, Y. Ofek, "Fractional Lambda Switching - Principles of Operation and Performance Issues," SIMULATION: Transactions of The Society for Modeling and Simulation International, Vol. 80, No. 10, Oct. 2004, pp. 527-544. (Abstract) (Full paper)
M. Baldi, Y. Ofek, "Comparison of Ring and Tree Embedding for Real-time Group Multicast," IEEE/ACM Transactions on Networking, Vol. 11, No. 3, June 2003, pp. 451-464. (Abstract)
Viet-Thang Nguyen, Mario Baldi, Renato Lo Cigno, Yoram Ofek, "Wavelength Swapping using Tunable Lasers for Fractional l Switching," Local and Metropolitan Area Networks, The 14th IEEE Workshop on LAN/MAN, 18-21 Sept. 2005, Pages: 1- 6.
M. Baldi, Y. Ofek, "Fractional Lambda Switching," IEEE International Conference on Communications (ICC2002), Optical Networking Symposium, New York, NY, USA, Apr. 2002, pp. 2692-2696. (Abstract) (Full paper)
M. Baldi, Y. Ofek, "Realizing Dynamic Optical Networking," Optical Networks Magazine, Special Issue "Dynamic Optical Networking: around the Corner or Light Years Away?", Vol. 4, No. 5, Sep./Oct. 2003, pp. 100-111. (Abstract) (Full paper)
A. Pattavina, M. Bonomi, Y. Ofek, �Performance evaluation of time driven switching for flexible bandwidth provisioning in WDM networks,� IEEE Globecom 2004, Dallas, Texas, vol. 3, pp 1930-1935. (Abstract)
D. Grieco, A. Pattavina and Y. Ofek, �Fractional Lambda Switching for Flexible Bandwidth Provisioning in WDM Networks: Principles and Performance,� IEEE Globecom 2003(Abstract)
M. Baldi, Y. Ofek, "UTC for Enabling New Applications and Services in GRID Networks," AICA 2005, Udine (Italy), Oct. 2005. (Abstract) (Full paper)
V.-T. Nguyen, M. Baldi, R. Lo Cigno, and Y. Ofek, "Wavelength Swapping using Tunable Lasers for Fractional ? Switching," 14th IEEE Workshop on Local and Metropolitan Area Networks, Chania, Crete (Greece), Sep. 2005. (Abstract) (Full paper)
M. Baldi, Y. Ofek, "Dynamic Optical Switching: The Network is the Memory," 11th IEEE International Conference on Software, Telecommunications and Computer Networks (SoftCOM 2003), Split, Dubrovnik (Croatia), Ancona, Venezia (Italy), Oct. 2003, pp. 631-635. (Abstract) (Full paper)
M. Baldi, Y. Ofek, "Grooming and Degrooming with Coordinated Universal Time (UTC)," Workshop on Contemporary Communications, 11th IEEE International Conference on Software, Telecommunications and Computer Networks (SoftCOM 2003), Split, Dubrovnik (Croatia), Ancona, Venezia (Italy), Oct. 2003, pp. 63-67. (Abstract) (Full paper)
M. Baldi, Y. Ofek, "Global Time for Interactive Applications over Global Packet Networks," 4th International Workshop on Quality of Future Internet Services (QoFIS 2003), Stockholm, Sweden, Oct. 2003, Springer-Verlag Lecture Notes on Computer Science (LNCS) 2811, pp. 52-62. (Abstract) (Full paper)




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Y. Ofek, "Ultra Scalable Optoelectronic Switching Fabric for Streaming Media over IP," ISSPIT 2005 (IEEE International Symposium on Signal Processing and Information Technology)

ABSTRACT

As data traffic on the Internet continues to grow exponentially, there is a real need to solve the switch bottleneck by developing ultra-scalable switching fabrics. Although in recent years there have been a lot of efforts to solve the switching fabric scalability problem, in the optical domain, the proposed solutions have been (very) expensive, (very) complex and (much) larger than electronic switching fabric alternatives. Unfortunately, electrical interconnection of existing (off-the-shelf) electronic switching devices is very difficult due to wave reflections on transmission lines, impedance mismatching, crosstalk and noise. Consequently, electronic switching with electrical interconnections has major scalability limitations. Thus, the question is whether and how optical interconnects can be used to link off-the-shelf electronic switching devices in order to develop optoelectronic switching fabrics that can scale up to 10-100 terabit per second (Tb/s) capacity in a single chassis. In order to further increase the scalability of the proposed novel optoelectronic switching fabric a UTC-based (coordinated universal time) time driven switching or fractional lambda switching (FS) architecture is proposed. This novel low-complexity switching architecture capitalizes on the ubiquitous of UTC from GPS and Galileo. FS architecture is especially suitable to support high capacity streaming media applications over the Internet.




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Ofek, Pattavina - IEEE Globecom 2003

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Ofek, Pattavina - IEEE Globecom 2004

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Ofek, Pattavina - Journal paper 2004

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M. Baldi, Y. Ofek, "Fractional Lambda Switching - Principles of Operation and Performance Issues," SIMULATION: Transactions of The Society for Modeling and Simulation International, Vol. 80, No. 10, Oct. 2004, pp. 527-544.

ABSTRACT

This article introduces fractional lambda (�) switching (F�S) and studies its blocking issues. F�S uses a global common time reference (CTR) for implementing pipeline forwarding (PF) inside the network. A global CTR is conveniently realized with the UTC (coordinated universal time) standard. Resource reservation over an F�S network requires a schedule. As in other scheduling cases, a call may not be accepted, even though there is enough capacity, because the schedule is not available�the call is then considered blocked. This work studies the probability of call blocking as a function of link utilization. The results show that (especially if multiple-wavelength division multiplexing channels are deployed on optical links between fractional � switches) high-link utilization can be achieved with negligible call blocking, even when the switching fabric is a Banyan network.




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M. Baldi, Y. Ofek, "Comparison of Ring and Tree Embedding for Real-time Group Multicast," IEEE/ACM Transactions on Networking, Vol. 11, No. 3, June 2003, pp. 451-464.

ABSTRACT

In general topology networks, routing from one node to another over a tree embedded in the network is intuitively a good strategy, since it typically results in a route length of O(log n) links, being n the number of nodes in the network. Routing from one node to another over a ring embedded in the network would result in route length of O(n) links. However, in group (many-to-many) multicast, the overall number of links traversed by each packet, i.e., the networks elements on which resources must be possibly reserved, is typically O(N) for both tree and ring embedding, where N is the size of the group. This paper focuses on the tree versus ring embedding for real-time group multicast in which all packets should reach all the nodes in the group with a bounded end-to-end delay. In this paper, real-time properties are guaranteed by the deployment of time-driven priority in network nodes.In order to have a better understanding of the nontrivial problem of ring versus tree embedding, we consider the following group multicast scenarios: 1) static--fixed subset of active nodes, 2) dynamic--fixed number of active nodes (i.e., the identity of active nodes is changing over time, but its size remains constant), and 3) adaptive--the number and identity of active nodes change over time.Tree and ring embedding are compared using the following metrics: 1) end-to-end delay bound, 2) overall bandwidth allocated to the multicast group, and 3) signaling overhead for sharing the resources allocated to the group. The results are interesting and counterintuitive, since, as shown, embedding a tree is not always the best strategy. In particular, dynamic and adaptive multicast on a tree require a protocol for updating state information during operation of the group. Such a protocol is not required on the ring where the circular topology, and implicit token passing mechanisms are sufficient. Moreover, the bandwidth allocation on the ring for the three multicast scenarios is O(N), while on a general tree it is O(N) for the static multicast scenario and O(N2) for the dynamic and adaptive multicast scenarios.




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M. Baldi, Y. Ofek, "Fractional Lambda Switching," IEEE International Conference on Communications (ICC2002), Optical Networking Symposium, New York, NY, USA, Apr. 2002, pp. 2692-2696.

ABSTRACT

Fractional Lambda (�) Switching (F�S) adds the necessary efficiency to Wavelength Division Multiplexing (WDM) while preserving the simplicity of whole � switching. Due to its provisioning capability, from a fraction of STS-1 to a full optical channel capacity, F�S� will extend the reach of optical networking all the way to the network edges in the metro and enterprise. Finally, F�S� uniquely enables the implementation of dynamic all-optical switches since its operation does not require (1) optical processing (e.g., packet header processing) and (2) optical buffering.




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M. Baldi, Y. Ofek, "Realizing Dynamic Optical Networking," Optical Networks Magazine, Special Issue "Dynamic Optical Networking: around the Corner or Light Years Away?", Vol. 4, No. 5, Sep./Oct. 2003, pp. 100-111.

ABSTRACT

Electronic asynchronous packet switching has been developed since the early 1960s and now, at the dawn of the 21st century, it is a well-understood technology. On the other hand, all-optical packet switching, a major candidate for the realization of dynamic optical networking, is a new technology, currently undergoing research and development. In this paper we show that the transition from electronic to optical is not as straightforward as one would like to think.
The main thesis of this paper is that the transition to dynamic all-optical switching will require changing the current asynchronous packet switching paradigm. This is shown by focusing the analysis on the simple problem of optical memory, while not considering the more complex problems associated with optical packet header processing and switching as if they had been resolved - which is indeed not the case.
In order to evaluate optical memory, various comparative measures are used. For example, much more glass (Silicon) is needed for optical memory versus electronic memory, in fact a factor of 1 million! If we assume shrinking of Silicon circuitry by a factor of two every 18 months, the transition to optical packet switching will translate into reversing Moore's law by 30 years.
It will be shown that a common time reference (CTR) is needed for realizing the optical random access memory (O-RAM) required for dynamic optical networking. Furthermore, it is shown that by using coordinated universal time (UTC a.k.a. GMT) CTR can be globally distributed, then it is possible to (globally) distribute the O-RAM and, consequently, to realize a new dynamic optical networking architecture called Fractional Lambda Switching (F�S), that additionally, does not require optical header processing.




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M. Baldi, Y. Ofek, "UTC for Enabling New Applications and Services in GRID Networks," AICA 2005, Udine (Italy), Oct. 2005.

ABSTRACT

A central challenge in the GRID today is to develop applications and services, specifically, profitable services. such developed has to be supported by proper mapping from the logical/virtual application to the underlying combined/converged networking and computing physical infrastructure. Proper mapping should ensure: (1) well-defined resource allocation, such as: computing, storage, bandwidth - while guaranteeing (2) well-defined delay bounds. Proper use of UTC, ubiquitously and almost free of charge available from GPS and Galileo, enables proper (i.e., cost effective) allocation of computing and networking resources.




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V.-T. Nguyen, M. Baldi, R. Lo Cigno, and Y. Ofek, "Wavelength Swapping using Tunable Lasers for Fractional � Switching," 14th IEEE Workshop on Local and Metropolitan Area Networks, Chania, Crete (Greece), Sep. 2005.

ABSTRACT

Fractional Lambda Switching (F�S) is a novel proposal for the management of all-optical networks with sub-wavelength provisioning capability. The unique characteristic of F�S is the utilization of the UTC (coordinated universal time) for alignment and switching. Several central research issues are still open in F�S and need to be formally defined and analyzed. Within the scope of this paper, we introduce three novel switch architecture designs that are based on the use of tunable lasers. As an important goal, we introduce the notion �scheduling feasibility� that measure the number of possible different scheduling between an input and output time-frames.




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M. Baldi, Y. Ofek, "Dynamic Optical Switching: The Network is the Memory," 11th IEEE International Conference on Software, Telecommunications and Computer Networks (SoftCOM 2003), Split, Dubrovnik (Croatia), Ancona, Venezia (Italy), Oct. 2003, pp. 631-635.

ABSTRACT

This paper shows that the transition to dynamic all-optical packet switching, that fully exploits the benefits of fast dynamic optical components, will require changing the current asynchronous packet switching paradigm. This is shown by focusing on the relatively simple problem of optical memory, while assuming that the more complex problems associated with optical packet header processing and fast switching in the optical domain have been resolved - which is indeed not in the case. Various comparative measures are used in the optical memory evaluation. For example, much more glass (Silicon) is needed for optical memory than for electronic memory; in fact the ratio is on the order of 1 million. As shown, a common time reference (CTR) is needed for realizing the optical random access memory (O-RAM) required for optical packet switching. Furthermore, a CTR is used for both minimizing the O-RAM requirements and distributing the O-RAM in the network realizing a new optical network architecture called Fractional Lambda Switching (F�S).




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M. Baldi, Y. Ofek, "Grooming and Degrooming with Coordinated Universal Time (UTC)," Workshop on Contemporary Communications, 11th IEEE International Conference on Software, Telecommunications and Computer Networks (SoftCOM 2003), Split, Dubrovnik (Croatia), Ancona, Venezia (Italy), Oct. 2003, pp. 63-67.

ABSTRACT

Coordinated Universal Time (UTC) enables the efficient and cost effective implementation of a grooming and degrooming method. The number of times data packet headers are being decoded throughout a global network deploying a UTC is limited to the necessary minimum of one. The simple implementation of grooming and degrooming devices results in high scalability and low cost.




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M. Baldi, Y. Ofek, "Global Time for Interactive Applications over Global Packet Networks," 4th International Workshop on Quality of Future Internet Services (QoFIS 2003), Stockholm, Sweden, Oct. 2003, Springer-Verlag Lecture Notes on Computer Science (LNCS) 2811, pp. 52-62.

ABSTRACT

This work is present that global time (a.k.a. time-of-day or coordinated universal time - UTC) is essentital in maximizing user perceived quality of service, while eliminating both switching bottleneck - critical in very high capacity network core - and communications link bottlenecks - at the low speed access (e.g., wireless and DSL). Global time obtained, for example, from GPS (Global Positioning System) or Galileo, is used in the design of all streaming media applications such as toll quality telephony, videotelephony and videoconferencing. The proposed solution, that can be applied to the Internet without changes to any of the existing protocols, provides a guaranteed quality service to each application without requiring nodes to keep state information on microflows.

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