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Optical Network Management and Control
Robert Doverspike, Jennifer Yates
Proceedings of the IEEE,
2012.
[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 Proceedings of the IEEE. , Volume TBD, Issue TBD, 2012-05-01
{While dense wavelength division multiplexing equipment has been deployed in networks of major telecommunications carriers for over a decade, the capabilities of its networking and associated network control and management have not caught up to those of digital cross-connect systems and packet-switched counterparts in higher layer networks. We shed light on this situation by examining the current structure of the optical layer, its relationship to other network technology layers, and current network management and control implementations. We provide additional insight by explaining how a combination of business and technical perspectives has driven evolution of the optical layer. We conclude by exploring activities to close this gap in the future.}
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.}
Traffic Types and Growth in Backbone Networks (SLIDES)
Alexandre Gerber, Robert Doverspike
in Proc. of OFC/NFOEC, INVITED PAPER,
2011.
[PDF]
[BIB]
{We review the growth of the different sources of data traffic on backbones, highlight the importance and nature of IP services today, and discuss the implications on content distribution and efficient use of backbone capacity.}
Traffic Types and Growth in Backbone Networks
Robert Doverspike, Alexandre Gerber
in Proc. of OFC/NFOEC, INVITED PAPER,
2011.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC 2011 , 2011-03-06
{We review the growth of the different sources of data traffic on backbones, highlight the importance and nature of IP services today, and discuss the implications on content distribution and efficient use of backbone capacity.}
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.}
Network architecture for joint failure recovery and traffic engineering
Dahai Xu, Robert Doverspike, David Johnson, Martin Suchara, Jennifer Rexford
Sigmetrics 2011,
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 SIGMETRICS , 2011-06-07.
{Today's networks typically handle traffic engineering (e.g., tuning the routing-protocol parameters to optimize the flow of traffic) and failure recovery (e.g., pre-installed backup paths) independently. In this paper, we propose a unified way to balance load efficiently under a wide range of failure scenarios. Our architecture supports flexible splitting of traffic over multiple precomputed paths, with efficient path-level failure detection and automatic load balancing over the remaining paths. We propose two candidate solutions that differ in how the routers rebalance the load after a failure, leading to a trade-off between router complexity and load-balancing performance. We present and solve the optimization problems that compute the configuration state for each router. Our experiments with traffic measurements and topology data (including shared risks in the underlying transport network) from a large ISP identify a "sweet spot" that achieves near-optimal load balancing under a variety of failure scenarios, with a relatively small amount of state in the routers. We believe that our solution for joint traffic engineering and failure recovery will appeal to Internet Service Providers as well as the operators of data-center networks.}
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.}
A network design technique for selective restoration
Kostas Oikonomou, Robert Doverspike, Rakesh Sinha
OFC 2011,
2011.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in proceedings of OFC 2011 (Optical Society of America). , 2011-03-09
{We outline a network design technique that exploits differences in the failure
rate and impact of network elements to produce a more efficient design. We
demonstrate its efficacy on a Tier-1 backbone network.}
Proactive Network Management of IPTV Networks
Rakesh Sinha, Kadangode Ramakrishnan, Robert Doverspike, Dahai Xu, Jorge Pastor, Aman Shaikh
2010.
[PDF]
[BIB]
{Consumer communications and entertainment services, including broadcast TV and VoIP require service providers to meet stringent availability and latency constraints. When a packet technology, such as IP, is used to transport these services, this also poses stringent packet loss requirement on the network. This aspect of IPTV, where impairments have consumer-visible impact and potential public relations consequences, creates new challenges in protocol design, as well as network management. The key to operating an effective network is to expand beyond the typical ?reactive? network management approach to be able to anticipate and manage potential network problems. This paper describes network management techniques deployed in a production IPTV network with over 2 million customers. }
Cross-Layer Techniques for Failure Restoration of IP Multicast with Applications to IPTV
Kadangode Ramakrishnan, Robert Doverspike, Murat Yuksel
2009.
[PDF]
[BIB]
{Broadcast TV distribution over an IP network requires stringent QoS constraints, such as low latency and loss. Streaming content in IPTV is typically delivered to the distribution points on the IP backbone using IP multicast protocols such as Protocol Independent Multicast Source Specific Mode (PIM-SSM). Link-restoration using MPLS or layer-2 Fast Reroute (FRR) is a proven failure restoration technique at the IP layer. Link-based FRR creates a pseudo-wire or tunnel in parallel to the IP adjacencies (links); and thus, single link failures are transparent to the Interior Gateway Protocol (IGP). Although one may choose the back-up path?s IGP link weights to avoid traffic overlap during any single physical link failure, multiple failures may still cause traffic overlap with FRR. We present a cross-layer restoration approach that combines both FRR-based restoration for single link failure and ?hitless? (i.e., without loss) PIM tree reconfiguration algorithms to prevent traffic overlap when multiple failures occur. Addl AT&T author: Wang, Dongmei }
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. }
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. }
Evolution of IP/OL Performance Management
Robert Doverspike, Jennifer Yates, Jorge Pastor, Martin Birk
2006.
[PPT]
[BIB]
Packet aware transport for metro networks
Thomas Afferton, Robert Doverspike, Charles Kalmanek, Kadangode Ramakrishnan
IEEE Communication Magazine,
2004.
[BIB]
{Today's metro networks have evolved from the need to support traditional voice and private line services. However, the tremendous growth in access to Frame Relay, ATM, IP and Ethernet services, coupled with the desire of enterprise customers to interconnect via Ethernet interfaces, suggests the need for a new approach. This paper proposes a new architecture for Packet-Aware technologies to provide efficient aggregation and switching of packet traffic in metro networks. The PATN has the potential to provide significant cost savings to carriers by reducing the number of network elements, reducing transport costs through statistical multiplexing, and eliminating the need for redundant multiplexing operations. HB8420000-040104-01TM This is an abstract of the previous version. }
Efficient restoration capacity design in MPLS networks
Guangzhi Li, Dongmei Wang, Jennifer Yates, Charles Kalmanek, Robert Doverspike
2004.
[DOC]
[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
IEEE copyright policy.
Congestion control in resilient packet rings
Dongmei Wang, Kadangode Ramakrishnan, Charles Kalmanek, Robert Doverspike, Aleksandra Smiljanic
7th INFORMS Telecommunications Conference,
2004.
[BIB]
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Network Performance And Reliability Evaluation Taking Into Account Multiple Traffic Matrices,
Tue Aug 30 16:06:06 EDT 2011
Network performability characteristics with improved accuracy are derived by taking into account, in the various analyzed network failure states, attributes of elements at the logical level other than just the capacities of edges, as well as by taking into account one or more "abstract components," such as scheduled maintenance, and by using multiple traffic matrices.
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.
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.
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.
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.
Link selection schemes for avoiding channel contention,
Tue Nov 11 18:13:09 EST 2008
United States Patent: 7450516A connection in an optical communication system is routed over a sequence of cross-connects and aggregated links comprising multiple links. A different link selection algorithm is used for service provisioning than is used for restoration, i.e., after a cable cut or other failure or incident has made one or paths in the network suddenly unavailable. In particular, a special link selection algorithm called the Interleave algorithm is used for restoration different from the well known Best-Fit algorithm used for provisioning. The Interleave algorithm substantially reduces the probability of glare while maintaining near-optimum capacity utilization.
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.
Methods and systems for fast restoration in a mesh network of optical cross connects,
Tue Aug 08 18:11:28 EDT 2006
Communication is restored in a fiber optic network by placing error detection circuitry at the add/drop ports of the network nodes of the network. If the error detection circuitry detects an error condition for a communication signal traversing a normal communication path within the network, the communication signal is rerouted along a restoration communication path that is node and span disjoint from the first communication path. By requiring a restoration path to be node and span disjoint from the normal communication path, error detection circuitry need only be placed at the end nodes of the normal communication path. By allowing each node in the restoration path to dynamically choose the particular channels that can accommodate a particular communication signal at the time of the restoration, efficient use of available resources is gained. The result is a cost effective network that restores communication in times competitive to that of SONET rings.
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.
Methods And Systems For Fast Restoration In A Mesh Network Of Optical Cross,
Tue Nov 29 18:10:38 EST 2005
The present invention provides methods and systems for restoring communication in a fiber optic network by placing error detection circuitry at the add/drop ports of the network nodes of the network. If the error detection circuitry detects an error condition for a communication signal traversing a normal communication path within the network, the communication signal is rerouted along a restoration communication path that is node and span disjoint from the first communication path. By requiring a restoration path to be node and span disjoint from the normal communication path, error detection circuitry need only be placed at the end nodes of the normal communication path. By allowing each node in the restoration path to dynamically choose the particular channels that can accommodate a particular communication signal at the time of the restoration, efficient use of available resources is gained. The result is a cost effective network that restores communication in times competitive to that of SONET rings.
Optical layer quasi-centralized restoration,
Tue Aug 01 18:05:35 EDT 2000
A wavelength-switching, mesh-based restoration method among a network of optical cross-connects (OXCs) is disclosed. The method is defined as quasi-centralized in that the network is first partitioned into a plurality of subnetworks, then a single restoration controller is defined for each separate subnetwork. The subnetwork partitioning is defined as being either minimally overlapping, meaning that the OXCs are clustered in their network topology, with only a few links required to join the various, autonomous subnetworks, or highly overlapping, meaning that the OXCs are defined as being included in more than one subnetwork. Each subnetwork restoration controller (SRC) includes a network graph and is therefore responsible for providing restoration around faults recognized in its own subnetwork.
INFORMS Fellow, 2006.
