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Cost Optimization Using Regenerator Site Concentration and Routing in ROADM Networks
Rakesh Sinha, Angela Chiu, Mark Feuer, Guangzhi Li, Sheryl Woodward, Weiyi Zhang, Balagangadhar G Bathula, Keren Bergman, Robert Doverspike, Peter Magill
DRCN 2013,
2013.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2012. , 2013-03-04
{The advent of colorless and non-directional reconfigurable
optical-add-drop multiplexers (ROADMs) will enable
flexible pre-deployment of optoelectronic regenerators in future
optical networks. Compared to the current practice of installing
regenerators only when a circuit needs them, pre-deployment
will allow service providers to achieve rapid provisioning and
restoration. The pre-deployed regenerators should be concentrated
in a selected subset of ROADM sites in order to attain high
utilization and to reduce operational costs. We prove that the
resulting optimization problem is NP-hard and present an efficient
heuristic for this problem that takes into account both the cost of
individual circuits (regenerator cost and transmission line system
cost) and the probability of a given circuit request, as well as
the number of regenerator sites. We provide various methods
to reduce the number of regenerator sites, if low probability
demands are allowed to have slightly costlier paths. Specific
network examples show that the proposed heuristic has near
optimal performance under most studied scenarios. We present
results for several different cost models. We have also evaluated
the heuristic for survivable optical networks, in which a second,
disjoint path must be supported for each circuit.}
Simulations of a Service Velocity Network Employing Regenerator Site Concentration
Mark Feuer, Balagangadhar Bathula, Daniel Bihon, Angela Chiu, Inwoong Kim, Guangzhi Li, Paparao Palacharla, Rakesh Sinha, Xi Wang, Sheryl Woodward, Weiyi Zhang
OFC/NFOEC2012 conference,
2012.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC/NFOEC2012 conference. , 2012-03-04
{We use Monte Carlo simulations of quasi-static traffic growth to study concentration of regenerator sites in dynamic photonic networks supporting service velocity. Idle regenerators can be reduced by >60% compared to unrestricted regeneration sites.}
On Shared Risk Link Group Optimization (Invited)
Guangzhi Li, Dongmei Wang, Timothy Gallivan, Robert Doverspike
Journal of optical communication networks,
2012.
[LINK]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2012 , Volume $vol, 2012-09-13
{Abstract— Shared Risk Link Groups (SRLGs) have been investigated during the past 10 years due to optical network innovation and deployment. Dense Wavelength Division Multiplexing (DWDM) technology has significantly increased the data transmission capability per fiber. Service providers build their overlay networks, such as IP networks, on top of optical networks and all optical networks are built over some combination of DWDM equipment and fibers. If there is a single DWDM system outage or fiber outage, the set of overlay network links dependent on the failed resource would all fail at the same time. The set of links failed by a common resource outage is called a shared risk link group (SRLG). SRLGs have been designed and implemented in many network planning tools and some network routing protocols. A single SRLG represents one potential outage (or failure mode) and a large service provider’s network could easily contain tens of thousands of failure modes. The greater the number of SRLGs, the more difficult it is to attain good performance from planning tools (like routers) whose computations are dependent on the number of SRLGs. For some routing protocols using SRLG information, the situation becomes even worse because a routing protocol may have space constraints to hold a limited number of SRLGs. These issues create a challenge to optimize the SRLG calculations such that the SRLG-related functions are not impacted or the impacts to the SRLG-related functions are limited. This paper takes a closer look at the SRLG optimization issue and proposes algorithms for how to reduce the number of SRLGs for different applications. }
On Shared Risk Link Group Optimization
Guangzhi Li, Dongmei Wang, Robert Doverspike, Timothy Gallivan
OFCNFOEC 2012,
2012.
[LINK]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in OFCNFOEC 2012. , 2012-03-04, http://www.ofcnfoec.org/home.aspx
{this paper takes a closer look at the shared risk link group (SRLG) optimization issue and proposes algorithm on how to reduce the size of the SRLGs for different applications with correctness proofs.}
On Concentrating Regenerator Sites in ROADM Networks
Rakesh Sinha, Angela Chiu, Guangzhi Li, Weiyi Zhang, Mark Feuer, Sheryl Woodward, Balagangadhar G. Bathula, Keren Bergman, Inwoong Kim, Paparao Palacharla
OFC/NFOEC2012 conference,
2012.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC 2012. , 2012-03-04
{Concentrating optical regenerators in a subset of network nodes provides significant savings. We present a
heuristic for choosing this subset. Our results are within 1 or 2 of optimal in the studied cases.}
SRLG-Diverse Routing of Multiple Circuits in a Heterogeneous Optical Transport Network
Dahai Xu, Guangzhi Li, Byrav Ramamurthy, Angela Chiu, Dongmei Wang, Robert Doverspike
International Workshop on Design of Reliable Communication Networks (DRCN) 2011,
2011.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in International Workshop on Design of Reliable Communication Networks (DRCN) 2011. , 2011-10-12
{Network planners are often requested to provision multiple physically-diverse high-speed circuits over a large carrier's core (inter-city) DWDM network, which consists of multiple layers and heterogeneous vendor systems. Optimally provisioning such circuits while avoiding shared risk link group (SRLG) failures is an NP-hard problem. In this paper, we propose a novel hybrid two-step approach: pre-processing with Integer Linear Programming (ILP) for diverse routing and post-processing for regenerator placement and wavelength assignment. This approach has been implemented in a prototype network planning tool. According to our experiments, most of the cases for a typical large carrier's core transport network can be solved within 1 minute, even with tens of thousands of binary decision variables, which allows interactive use by network planners.}
IP Backbone Design for Multimedia Distribution: Architecture and Performance
Guangzhi Li, Robert Doverspike, Kadangode Ramakrishnan, Dongmei Wang, Kostas Oikonomou
2006.
[PDF]
[BIB]
{Multimedia distribution, especially broadcast TV distribution over an IP network requires high bandwidth combined with tight latency and loss constraints, even under failure conditions. Due to high bandwidth requirements of broadcast TV distribution, use of IP-based multicast to distribute TV content is needed for capacity efficiency. The protection and restoration mechanisms currently adopted in IP backbones use either IGP re-convergence or some form of Fast Reroute. The IGP re-convergence mechanism is too slow for real-time multimedia distribution while a drawback of fast reroute is that since they re-route traffic on a link-basis (instead of end-to-end) they can suffer traffic overlap during failures. Here traffic overlap is defined as the same traffic passing through the same link along the same direction more than once, which requires more link capacity. We propose a method that interacts with Fast Reroute and multicast to minimize traffic overlap during failures. We also present an algorithm for link-weight setting that avoids traffic overlap for any single link failure. Performance analysis shows that the proposed method improves network service availability and significantly reduces the impact of failure events. version 2 record added in error; please see version 1 for paper. }
A GMPLS based control plane testbed for dnd-to-end services
Guangzhi Li, Jennifer Yates, Dongmei Wang, Panagiotis Sebos, Joel Gottlieb, Albert Greenberg
2005.
[DOC]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Efficient restoration capacity design in MPLS networks
Guangzhi Li, Dongmei Wang, Jennifer Yates, Charles Kalmanek, Robert Doverspike
2004.
[DOC]
[BIB]
Efficient Segment-by-Segment Restoration
Dongmei Wang, Guangzhi Li, Jennifer Yates, Charles Kalmanek
2004.
[PDF]
[BIB]
Economic Analysis of IP/Optical Network Architectures
Guangzhi Li, Dongmei Wang, Charles Kalmanek, Jennifer Yates, Robert Doverspike
2004.
[PDF]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Detail study of IP/Reconfigurable Optical Network Architectures
Guangzhi Li, Dongmei Wang, Jennifer Yates, Robert Doverspike, Charles Kalmanek
2004.
[DOC]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
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Survivability Issues in IP / Optical Networks
2003.
[BIB]
Integrated IP/optical approach for efficient access router failure recovery, An
Panagiotis Sebos, Jennifer Yates, Guangzhi Li, Monica Lazer, Rubenstein Dan
2003.
[PDF]
[BIB]
Efficient algorithm for OSPF subnet aggregation
Guangzhi Li, Dongmei Wang, Jennifer Yates, Charles Kalmanek, Aman Shaikh
2003.
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Ultra-fast IP link and interface provisioning with applications to IP restoration
Panagiotis Sebos, Jennifer Yates, Guangzhi Li, Dongmei Wang, Monica Lazer, Albert Greenberg, Rubenstein Dan
2002.
[DOC]
[BIB]
Control plane design for reliable optical networks
Guangzhi Li, Jennifer Yates, Charles Kalmanek, Dongmei Wang
2002.
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Method And Apparatus For Generating A Set Of Aggregates,
Tue Mar 08 16:04:39 EST 2011
A method and apparatus for generating at least one aggregate (e.g., a set of aggregates) for a given area of a network such that the number of aggregates is minimized subject to a maximum acceptable path selection error are disclosed. One operational benefit of the present method is that network administrators can select aggregates for an area based solely on the topology of the area without worrying about remaining areas of the OSPF network. Another benefit is that the present method enables trade-offs between the number of aggregates and the bound on the path selection error.
Two-Phase Fast Reroute Mechanism With Optimized Traffic Engineering,
Tue Dec 28 15:05:23 EST 2010
Systems and methods are described for restoring IP traffic flows routed in an IP network in less than 100 ms after the IP network sustains a network failure. The systems and methods are a two-phase fast reroute that uses distributed optimized traffic engineering during backup tunnel restoration and end-to-end tunnel restoration that maximizes sharing among all independent failure scenarios and minimizes the total capacity, total cost, or a linear combination of the two. For defined failure condition scenarios, restoration traffic is routed using pre-computed backup tunnels using a constrained shortest path first method where link weights along the path are chosen dynamically and depend on available and total capacity of the link, latency, and other cost measures such as IP port costs. During the capacity allocation phase, the method reuses capacity already allocated for other independent failure scenarios as much as possible but also adds capacity, if necessary. When an actual IP network failure occurs, the backup tunnels are used to immediately restore service to affected IP network traffic flows. In parallel, end-to-end tunnels corresponding to each affected traffic flow are rerouted and once the rerouting process is complete, traffic is switched over from the old end-to-end tunnel routes (using backup tunnels) to new end-to-end tunnel routes without using backup tunnels.
System And Method For Restoration In A Multimedia IP Network,
Tue Nov 09 15:04:59 EST 2010
Disclosed herein are systems, methods, and computer readable media for modifying IP backbone link weights such that multicast traffic and unicast traffic will not travel on a same path between nodes. The method comprises assigning link weights to nodes within an IP backbone such that multicast forwarding paths and unicast forwarding paths are failure disjoint, and delivering undelivered multicast packets using IP unicast encapsulation to the loopback address of next hop router on a multicast tree upon link/interface failure.
Method For Unidirectional And Bidirectional Label Switched Path Setup In A Label Switched Network,
Tue Aug 24 15:04:28 EDT 2010
Label contention in a label switched network is resolved by applying a contention resolution scheme that reconciles policies for handling unidirectional and bidirectional label switched path setup.
Arrangement For Reducing Multiplexing And Demultiplexing Cost In Ultra Long Haul (ULH) All-Optical Networks By Minimizing Number Of Required Mux/Demux Groups,
Tue Aug 03 15:04:18 EDT 2010
Multiplex-demultiplex (mux/demux) "groups" multiplex and demultiplex a predetermined maximum number of optical wavelengths. A method for assigning wavelengths of fiber links and mux/demux groups to given traffic (or traffic segments) in an optical communications network, minimizes over all terminals a total number of mux/demux groups required. The method (FIG. 5) involves (510) sorting the terminals in order of size of load. Further, for each traffic segment between pairs of first and second terminals, the method involves (516) assigning a smallest wavelength that is available between the first and second terminals and that is available on the segment path between the terminals; and in the terminals, (518) deploying mux/demux groups supporting the assigned wavelengths. A modified method (FIGS. 6A, 6B), as well as a method for dynamically assigning and deploying newly arriving traffic segments (FIG. 7), are also provided.
Method For Selecting A Restoration Path In A Mesh Network,
Tue Mar 30 15:03:40 EDT 2010
A method of selecting a restoration path in a mesh telecommunication network is disclosed that advantageously is practical and flexible and may be pre-computed along with a service connection path during the setup of the connection. The information used to select the restoration path can be advantageously distributed among nodes in the network.
Method For Restoration And Normalization In A Mesh Network,
Tue Jan 26 15:03:16 EST 2010
The present invention is directed to methods for signaling that enable bandwidth reservation, path restoration, path normalization, and path removal in a mesh network that supports shared mesh restoration.
System And Method For Routing Packet Traffic,
Tue Nov 03 16:08:08 EST 2009
A system and method for routing packet traffic is disclosed. A system that incorporates teachings of the present disclosure may include, for example, a router having a routing element that routes packet traffic according to Internal Gateway Protocol (IGP) weights that prevent multicast packet traffic and unicast packet traffic from occupying a common unidirectional link. Other embodiments are disclosed.
Method for selecting restoration path in a mesh network,
Tue Nov 11 18:13:08 EST 2008
A method of selecting a restoration path in a mesh telecommunication network is disclosed that advantageously is practical and flexible and may be pre-computed along with a service connection path during the setup of the connection. The information used to select the restoration path can be advantageously distributed among nodes in the network.
Method for unidirectional and bidirectional label switched path setup in a label switched network,
Tue Nov 20 18:12:27 EST 2007
Label contention in a label switched network is resolved by applying a contention resolution scheme that reconciles policies for handling unidirectional and bidirectional label switched path setup.
Method for selecting a restoration path in a mesh network,
Tue Feb 20 18:11:54 EST 2007
A method of selecting a restoration path in a mesh telecommunication network is disclosed that advantageously is practical and flexible and may be pre-computed along with a service connection path during the setup of the connection. The information used to select the restoration path can be advantageously distributed among nodes in the network.
Method for selecting a restoration path in a mesh network,
Tue Jan 03 18:10:45 EST 2006
A method of selecting a restoration path in a mesh telecommunication network is disclosed that advantageously is practical and flexible and may be pre-computed along with a service connection path during the setup of the connection. The information used to select the restoration path can be advantageously distributed among nodes in the network.
