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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 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.}
Bandwidth on Demand for Inter-Data Center Communication
Ajay Mahimkar, Robert Doverspike, Emmanuil Mavrogiorgis, Jorge Pastor, Jennifer Yates, Mark Feuer, Sheryl Woodward, Peter Magill, Angela Chiu
ACM SIGCOMM Workshop on Hot Topics in Networks,
2011.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM SIGCOMM Workshop on Hot Topics in Networks , 2011-10-15.
{Cloud service providers use replication across geographically distributed data centers to improve end-to-end performance as well as to offer high reliability under failures. Content replication often involves the transfer of huge data sets over the wide area network and demands high backbone transport capacity. In this paper, we discuss how a Globally Reconfigurable Intelligent Photonic Network (GRIPhoN) between data centers could improve operational flexibility for cloud service providers. The proposed GRIPhoN architecture is an extension of earlier work [34] and can provide a bandwidth-on-demand service ranging from low data rates (e.g., 1 Gbps) to high data rates (e.g., 10-40 Gbps). The inter-data center communication network which is currently statically provisioned could be dynamically configured based on demand. Today's backbone optical networks can take several weeks to provision a customer's private line connection. GRIPhoN would enable cloud operators to dynamically set up and tear down their connections (sub-wavelength or wavelength rates) within a few minutes. GRIPhoN also offers cost-effective restoration capabilities at wavelength rates and automated bridge-and-roll of private line connections to minimize the impact of planned maintenance activities.}
Performability analysis of multi-layer restoration in a satellite network
Kostas Oikonomou, Kadangode Ramakrishnan, Robert Doverspike, Angela Chiu, Rakesh Sinha, Miguel Martinez-Heath
2007.
[TXT]
[BIB]
{Abstract. The ability of an IP backbone network to deliver robust and dependable communications relies on quickly restoring service after failures. Service-level agreements (SLAs) between a network service provider and customers typically include overall availability and performance objectives. To achieve the desired SLA, we have developed a methodology for the combined analysis of performance and reliability (performability)of networks across multiple layers by modeling the probabilistic failure state space in detail and analyzing different restoration alternatives. This methodology has been used to analyze large commercial IP-over-Optical layer networks. In this paper we extend our methodology to evaluate restoration approaches for an IP-based satellite backbone network. Because of the environment in which they operate (long delay links, frequent impairments), satellite networks pose an interesting challenge to typical restoration strategies. We describe the potential multi-layer restoration alternatives and compare their performability. Interestingly, while it is commonly thought that SONET ring restoration at the lower layer improves overall reliability, we find that it may not always improve performability in this environment. }
Shared Mesh Restoration With Pre-Configured Standby Lightpaths,
Tue Apr 03 16:09:50 EDT 2012
Systems and methods are described for restoring wavelength services in mesh networks using pre-configured, standby lightpaths. The standby lightpaths are pre-cross-connected lightpaths that provide connectivity between switching nodes having a fiber link of degree-2 or higher. The restoration method overcomes the problem of optical impairments for long haul connections, avoids wavelength power balancing delays, provides wavelength conversion for capacity efficiency, and allows sharing of links across nonsimultaneous failures.
Method And Apparatus For Communications Traffic Engineering,
Tue May 24 16:05:15 EDT 2011
This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
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.
Methods Of Restoration In An Ultra-Long Haul Optical Network,
Tue Sep 28 15:04:49 EDT 2010
A method includes receiving a restoration indicator associated with a path that includes an optical cross-connect (OXC). The OXC is reconfigured from a standby configuration to a restoration configuration in response to the restoration indicator. An optical signal received in a first direction at a first wavelength is optically regenerated to produce an optical signal in the first direction at a second wavelength. An optical signal received in a second direction at the second wavelength is optically regenerated to produce an optical signal in the second direction at the first wavelength.
Method And Apparatus For Communications Traffic Engineering,
Tue Aug 17 15:04:24 EDT 2010
This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
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.
Arrangement For Low Cost Path Protection For Optical Communications Networks,
Tue Jun 23 16:07:31 EDT 2009
An arrangement provides low cost path protection in an optical communications network. The arrangement has a portion 3 that provides (broadcasts) an outbound optical signal, and at least first and second transmitting portions 202, 206 transmit the outbound optical signal simultaneously onto at least first and second respective mutually distinct optical pathways 231, 232. Meanwhile, a selection arrangement 204 selects among plural incoming optical signals (via 1, 5) according to a SELECT control signal 228 to provide a selected signal, and an analyzer 222 analyzes characteristics of the selected signal to provide the SELECT control signal 228.
Methods Of Restoration In An Ultra-Long Haul Optical Network,
Tue Apr 28 16:07:24 EDT 2009
A method includes receiving a restoration indicator associated with a path that includes an optical cross-connect (OXC). The OXC is reconfigured from a standby configuration to a restoration configuration in response to the restoration indicator. An optical signal received in a first direction at a first wavelength is optically regenerated to produce an optical signal in the first direction at a second wavelength. An optical signal received in a second direction at the second wavelength is optically regenerated to produce an optical signal in the second direction at the first wavelength.
Arrangement for low cost path protection for optical communications networks,
Tue Jun 17 18:12:54 EDT 2008
An arrangement provides low cost path protection in an optical communications network. The arrangement has a portion 3 that provides (broadcasts) an outbound optical signal, and at least first and second transmitting portions 202, 206 transmit the outbound optical signal simultaneously onto at least first and second respective mutually distinct optical pathways 231, 232. Meanwhile, a selection arrangement 204 selects among plural incoming optical signals (via 1, 5) according to a SELECT control signal 228 to provide a selected signal, and an analyzer 222 analyzes characteristics of the selected signal to provide the SELECT control signal 228.
Method and apparatus for communications traffic engineering,
Tue Jun 12 18:12:05 EDT 2007
This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
Arrangement for low cost path protection for optical communications networks,
Tue Jun 05 18:12:05 EDT 2007
An arrangement provides low cost path protection in an optical communications network. The arrangement has a portion 3 that provides (broadcasts) an outbound optical signal, and at least first and second transmitting portions 202, 206 transmit the outbound optical signal simultaneously onto at least first and second respective mutually distinct optical pathways 231, 232. Meanwhile, a selection arrangement 204 selects among plural incoming optical signals (via 1, 5) according to a SELECT control signal 228 to provide a selected signal, and an analyzer 222 analyzes characteristics of the selected signal to provide the SELECT control signal 228.
Arrangement for low cost path protection for optical communications networks,
Tue Jan 30 18:11:50 EST 2007
An arrangement provides low cost path protection in an optical communications network. The arrangement has a portion 3 that provides (broadcasts) an outbound optical signal, and at least first and second transmitting portions 202, 206 transmit the outbound optical signal simultaneously onto at least first and second respective mutually distinct optical pathways 231, 232. Meanwhile, a selection arrangement 204 selects among plural incoming optical signals (via 1, 5) according to a SELECT control signal 228 to provide a selected signal, and an analyzer 222 analyzes characteristics of the selected signal to provide the SELECT control signal 228.
Method and apparatus for an architecture and design of internet protocol quality of service provisioning,
Tue Feb 14 18:10:52 EST 2006
An architecture, design, and realization for providing Quality of Service (QoS) to Internet Protocol (IP) networks based on a three-class differentiated service scheme where the service provider uses a resource management system and a schedule optimizer to enable the optimal use of bandwidth and buffer resources at each node along the various links between the ingress and egress points in a network. The resource reservation system checks to determine whether sufficient bandwidth resources are available along the path requested by the customer for a particular class. The schedule optimizer ensures that sufficient buffer resource allocations and parameter settings are made to optimally reach the predetermined QoS criteria for each of the three classes. The system also contains a mechanism supporting resource reservations providing additional resources along alternative paths if the selected path links fail in the network.
Method And Apparatus For Provisioning and Monitoring Internet Protocol Quality Of Service,
Tue Dec 06 18:10:40 EST 2005
An architecture, design, and realization for providing Quality of Service (QoS) to Internet Protocol (IP) networks based on a three-class differentiated service scheme where the service provider uses a resource management system and a schedule optimizer to enable the optimal use of bandwidth and buffer resources at each node or router along the various links between the ingress and egress points in a network. The resource reservation system checks to determine if sufficient bandwidth resources are available along the path requested by the customer for a particular class. The schedule optimizer ensures that sufficient buffer resource allocations and parameter settings are made to optimally reach the predetermined QoS criteria for each of the three classes. The system also contains a mechanism supporting resource reservations providing additional resources along alternative paths if the selected path links fail in the network.
