Resource Reservation Protocol-traffic Engineering Research Articles

Enhanced signaling crankback scheme in multi-domain and complex optical networks

In optical networks lightpath setup problems, researchers usually assume the optical networks to be a single domain. However, the optical networks develop toward to multi-domain and larger scale in practice. However, with the optical networks develop toward to complexity, conventional resource reservation protocol traffic engineering (RSVP-TE) protocol crankback schemes cannot meet the requirements of these new applications for real-time dynamic services and fast restoration with long propagation delays. In this letter, we focus on lightpath setup problems in multi-domain optical networks, mixed integer linear programming (MILP) formulations is presented. A heuristic algorithm base on network virtualization and source backtracking region re-routing (SBRR) crankback scheme is proposed. Simulation results show that, under different traffic patterns, the proposed algorithm achieves significant improvement on network resources occupation and lightpath setup latency in contrast with the conventional algorithms which were proposed base on a single domain network environment.

RSVP-TE Bilateral-Recursive Region Re-Routing Crankback Mechanism for Large-Scale Optical Networks

Abstract Cloud computing services and real-time Internet applications have spawned a large variety of potential requirements for quality of service (QoS), especially the latency and connection setup time. However, with the optical networks develop toward to larger scale, wider coverage and more users access, conventional resource reservation protocol traffic engineering (RSVP-TE) signal hop by hop transmission scheme cannot meet the requirements of these new applications for real-time dynamic services and fast restoration with long propagation delays. This paper proposes a novel RSVP-TE bilateral-recursive region re-routing crankback mechanism (BRCB) base on distributed path computation element (PCE) for generalized multiprotocol label switching (GMPLS) optical networks. In this mechanism, the backtracking nodes re-route and update the region routing paths which bypass the crankback and re-routing failure nodes when crankback occurs. It not only reduces the influencing factors of the scale of network, signaling crankback position and frequency to path connection setup time, but also avoids the backtracking of teardown messages.

An OAM function to improve the packet loss in MPLS‐TP domains for prioritized QoS‐aware services

SummaryThe emergence of new kinds of applications and technologies (e.g., data‐intensive applications, server virtualization, and big data technology) has led to a higher utilization of network resources. These services imply increased bandwidth consumption and unexpected congestions, especially in backbones. In this article, a novel proposal is studied with the aim of improving the performance of prioritized forwarding equivalence classes in congested Multiprotocol Label Switching Transport Profile (MPLS‐TP) domains. The congestion impact on those QoS‐aware services that require high reliability and low delay is analyzed. A new policy has been implemented on MPLS‐TP, which is a technology that provides QoS by means of flow differentiation in the Internet backbones. The proposal is known as Gossip‐based local recovery policy and is offered as an operation, administration, and management function to allow local recovery of lost traffic for MPLS‐TP privileged forwarding equivalence classes. In order to fulfill the requirements for implementation on MPLS‐TP, a minimum set of extensions to resource reservation protocol traffic engineering has also been proposed to provide self‐management capable routes. Finally, we have carried out a performance improvement measurement by means of an analytical model and simulations. Copyright © 2014 John Wiley & Sons, Ltd.

Multicast in Multi Protocol Label Switching: A comparison study between LDP and RSVP-TE

Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE), andLabel Distribution Protocol (LDP) may be used to set up Point toMulti Point (P2MP) trees in MPLS. RSVP-TE performs better inoptimizing network resources, while LDP is simpler but has noguarantee on resource optimization. This paper presents acomparative study between RSVP-TE and LDP in regards of resourceoptimization and the resulting impact on the amount of memoryconsumed. It shows that the amount of memory needed in the case ofRSVP-TE grows linearly as the size of the tree increases. Incontrast, an approximate constant behavior is observed in the caseof LDP, yielding an important scalability property. The paper thenproposes two extensions to LDP aiming to achieve better resourceoptimization. In both extensions, a new leaf is provided a partialtree knowledge, by involving either all the nodes of the tree oronly its leaves. The leaf joins the tree by connecting to theclosest node among the known ones. Valuable comparisons withRSVP-TE are performed, and they represent an important backgroundto decide when and how to use each protocol.

Novel control plane framework and protocol extensions for Spectrum-Efficient Optical Transport Networks

Spectrum-Efficient Optical Transport Networks (SE-OTN), the most important character of which is high spectrum efficiency due to flexible grid, have attracted much attention recently. However, it cannot be employed for practical use since most of the related protocols are immature. This paper mainly focuses on the framework and protocol extensions for the control plane of SE-OTN. A novel control plane framework is designed combining the advantages of Generalized Multi-Protocol Label Switching (GMPLS) and Path Computation Element (PCE), and several routing and spectrum assignment (RSA) models are built. Furthermore, motivation and extension solutions for Open Shortest Path First-Traffic Engineering (OSPF-TE), Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE), and PCE Protocol (PCEP) are proposed based on this framework. An experimental testbed of large-scale spectrum-efficient optical networks with the capability of supporting 1000 GMPLS-based control nodes has been built to validate the performance of the protocols and algorithms, and some numeric results and analysis are given finally. Numeric results show that our proposed Centralized Routing and Centralized Spectrum Assignment (CR+CSA) model has better performance than Centralized Routing and Distributed Spectrum Assignment (CR+DSA) and Distributed Routing and Distributed Spectrum Assignment (DR+DSA), and spectrum defragmentation algorithm based on spectrum compactness can get good performance in the CR+CSA model.

Analyses of soft-state signaling protocols in GMPLS-Based WDM networks

Wavelength-routed Generalized Multi-Protocol Label Switching (GMPLS) networks use Resource reSerVation Protocol—Traffic Engineering (RSVP-TE) as signaling protocol to set up and tear down lightpaths. RSVP-TE uses a soft-state control mechanism to manage lightpaths. In the soft-state control mechanism, each node sets a timer for each control state and resets the timer with refresh messages to maintain the state. When the timer expires due to losses of refresh messages, the control state is initialized and a reserved resource managed with the state is released. It has been considered that resource utilization of soft-state protocols is inferior to that of hard-state protocols, since soft-state protocols may reserve resources until control states are deleted due to timeout. Therefore, some extensions to promote the performance of soft-state protocols, such as message retransmission, have been considered. In this paper, we analyze the behavior of GMPLS RSVP-TE and its variants with a Markov model and analyze the performance of RSVP-TE. From the results, we demonstrate that resource utilization of RSVP-TE can be equivalent to that of a hard-state protocol when the loss probability of signaling messages is low. We also investigate the effectiveness of message retransmission and show that using message retransmission leads to poor resource utilization in some cases. Copyright © 2012 John Wiley & Sons, Ltd.

QoS Supported IPTV Service Architecture over Hybrid-Tree-Based Explicit Routed Multicast Network

With the rapid advance in multimedia streaming and multicast transport technology, current IP multicast protocols, especially PIM-SM, become the major channel delivery mechanism for IPTV system over Internet. The goals for IPTV service are to provide two-way interactive services for viewers to select popular program channel with high quality for watching during fast channel surfing period. However, existing IP multicast protocol cannot meet above QoS requirements for IPTV applications between media server and subscribers. Therefore, we propose a cooperative scheme of hybrid-tree based on explicit routed multicast, called as HT-ERM to combine the advantages of shared tree and source tree for QoS-supported IPTV service. To increase network utilization, the constrained shortest path first (CSPF) routing algorithm is designed for construction of hybrid tree to deliver the high-quality video stream over watching channel and standard quality over surfing channel. Furthermore, the Resource Reservation Protocol- Traffic Engineering (RSVP-TE) is used as signaling mechanism to set up QoS path for multicast channel admission control. Our simulation results demonstrated that the proposed HT-ERM scheme outperforms other multicast QoS-based delivery scheme in terms of channel switching delay, resource utilization, and blocking ratio for IPTV service.

OSNR-aware lightpath provisioning in distributed optical network

An optical signal-to-noise ratio (OSNR) aware lightpath provisioning mechanism (OSNR-LPM) is proposed for distributed optical networks. This OSNR-LPM takes the OSNR value of the lightwave along the lightpath into consideration when establishing the lightpath for the connection request using resource reservation protocol-traffic engineering (RSVP-TE). Moreover, the OSNR-LPM makes full advantages of the OSNR monitoring function in each node and assigns the lightwave by judging the OSNR value carried by the signaling message in order to guarantee the reliable establishment of the lightpath in the data plane.The simulation results show that the OSNR-LPM outperforms other lightpath assignment mechanisms in terms of real blocking probability in the data plane.

Rendezvous Multicast: A Novel Architecture for MPLS QoS Multicast

IP multicast and MPLS (multi-protocol label switching) are proposed to support emerging network applications effectively, extending current IP routing and switching mode in different ways. It is still in progress to combine IP multicast with MPLS properly. In this paper, a novel architecture, called Rendezvous MPLS Multicast, is proposed to support IP multicast in MPLS networks and to have the scalability of multicast routing, to achieve the label space reduction, and to solve some practical problems in implementation. A two-layered structure of control plane without multicast routing protocols is implemented by overlaying novel service control plane over the existing routing control plane to support multicast state aggregate. The interface between the two planes is formulated to support the interaction and cooperation. Moreover, the label distribution process for MPLS P2MP (point to multi-point) connection, with RSVP-TE (resource reservation protocol-traffic engineering) protocol, is extended to support aggregate of multiple label switching paths with traffic engineering and guarantee of quality of service. An algorithm of selecting Rendezvous Routers for Rendezvous MPLS Multicast has been presented. A test-bed with Linux-based implementations of MPLS multicast router and IP multicast service control system has also been constructed. The experimental results show its efficiency in terms of label space reduction and multicast traffic balancing, with the whole system adapting to the dynamic change of group members and network topology.

Accounting for Shared Regenerators in GMPLS-Controlled Translucent Optical Networks

In translucent optical networks, the usage of sparse opto-electronic regenerators permits to overcome optical signal quality degradations. In dynamic translucent optical networks, where lightpaths are established upon request, regenerators can be effectively time shared. However, the current generalized multiprotocol label switching (GMPLS) protocol suite does not consider how to dynamically reserve and release shared regenerators and how to distribute regenerator availability information to network nodes. In this paper, four <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Translucent</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Lightpath</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Dynamic</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Provisioning</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(TLDP)</i> schemes are proposed to establish lightpaths in dynamic distributed translucent optical networks. TLDP schemes differently combine the utilization of specific open shortest path first-traffic engineering (OSPF-TE) or resource reservation protocol-traffic engineering (RSVP-TE) extensions and shared regenerator availability information. Simulation results show that TLDP scheme based on OSPF-TE extensions obtains lower lightpath setup time, but higher control plane load than TLDP schemes based on RSVP-TE extensions. Moreover, schemes based on RSVP-TE extensions or on OSPF-TE extensions obtain the same lowest blocking probability.

Distributed Optical Control Plane Architectures for Handling Transmission Impairments in Transparent Optical Networks

Transmission impairments in wavelength-division- multiplexing (WDM) transparent optical networks accumulate along an optical path and determine the feasibility of lightpaths; hence, the impairments need to be managed efficiently by the control plane. This paper presents impairment-aware distributed optical control plane (OCP) based on enhancements to resource reservation protocol-traffic engineering (RSVP-TE) signaling protocol (S-OCP). In particular, four architectural options [K-sequential (K-SEQ), K-parallel (K-PAR), hop-by-hop (HbH), and full flooding (FF)] within the S-OCP approach are defined and compared. Simulation results show that a combination of HbH routing and feasibility check can be considered as a good compromise both in terms of blocking probability and control plane overhead. The feasibility of a signaling-based approach for the control plane is further demonstrated by comparing simulation results with the results obtained from the implementation of the proposed architectural options in a commercial generalized multiprotocol label switching (GMPLS) protocol emulator. Furthermore, we argue that the real networks will rarely be homogeneous concerning transponder types, creating the need for a transponder selection policy at the end nodes. We introduce and compare two policies: best-first and worst-first. The results obtained from our experiments show that a worst-first policy for selecting transponders can save up to 50% enhanced transponders thereby reducing the overall cost.

GMPLS-based optical slot switching access-distribution network with a 10 ns high-speed PLZT optical switch

We design and implement an optical slot switching network for bulk content transfer. To realize the slot switching network, we employ the generalized multiprotocol label switching (GMPLS) extension protocol to reserve and release slots dynamically according to the application. We use optical switches as relay points in the slot switching network, and we employ a 10ns high-speed (Pb,La)(Zr,Ti)O&lt;sub&gt;3&lt;/sub&gt; (PLZT) optical switch. We extend the resource reservation protocol-traffic engineering (RSVP-TE) and realize optical slot reservation. In the slot reservation, the proposed scheme allocates a slot in a frame for clients in order to guarantee the minimum bandwidth. The scheme considers the accelerated and tentative slot reservation. In the slot switching network, we use the PLZT optical switch. The PLZT switch can improve the bandwidth utilization by reducing the guard time between slots unlike the microelectromechanical system (MEMS) switch. To realize the slot switching network, we develop a PLZT optical switch system with a GMPLS-based controller. By experiment based on the experimental network, we confirm that we can realize the slot switching network. We consider the application of the proposed network as an access network for content distribution.

Hose 모델 VPN 서비스를 위한 NSIS 기반 자원 예약 프로토콜

본 논문에서는 NSIS(Next Step in Signaling) 시그널링 프로토콜을 기반으로 VPN(Virtual Private Network) QoS(Quality of Service) 서비스 모델인 Hose 모델 자원 준비(Resource Provisioning) 메커니즘에 따라 자원을 예약하고 관리하는 Hose-NSIS-QoSM을 제안한다. 구체적으로 Hose-NSIS-QoSM을 위한 NSIS 메시지 객체(Objects), QoS NSLP(NSIS Signaling Layer Protocol)/NTLP(NSIS Transport Layer Protocol)/RMF(Resource Management Function) 상태 테이블, NSIS 노드에서의 메시지 처리 과정을 정의하였다. 또한, MPLS 네트워크에서의 VPN의 Hose 기반 QoS 서비스 모델을 지원하기 위해 확장된 RSVP-TE(Resource Reservation Protocol-Traffic Engineering)를 이용하는 시그널링 방안인 Hose-RSVP-TE-QoSM과 본 논문에서 제안하는 방안인 Hose-NSIS-QoSM를 비교하였다. In this paper, we define a Hose-NSIS-QoSM, which reserves and manages resources according to the hose based resource provisioning mechanisms for supporting the VPN QoS(Quality of Service) using the NSIS(Next Step in Signaling) signaling protocol. Specifically, we specify the NSIS message objects, the structures of QoS NSLP(NSIS Signaling Layer Protocol)/NTLP(NSIS Transport Layer Protocol)/RMF(Resource Management Function) state tables and the processing of the signaling messages in NSIS nodes. Also, we compare the Hose-NSIS-QoSM with the Hose-RSVP-TE-QoSM that supports the hose based VPN QoS in the MPLS networks using the extended RSVP-TE mechanism.

Multicast with a new switching structure in optical networks

The emergence of new services demands for a multicast function in optical networks. At the same time, wavelength converters are introduced to increase the efficiency of wavelength usage. It is because of the high cost and complex architecture of optical multicast and wavelength conversion technology, that a new switch structure is introduced, in which optical splitters and wavelength converters are shared per-node. In order to accommodate this architecture, a multicast routing and wavelength assignment algorithm in a splitter–converter-sharing optical network and a changing link weight policy to balance network traffic are proposed. By extending RSVP-TE (Resource ReSerVation Protocol-Traffic Engineering) and OSPF-TE (Open Shortest Path First-Traffic Engineering), an optical multicast mechanism is provided, and message type, signaling flow, and finite state machine model are given. Simulations of NSFNET show that, when the number of splitters and converters are 50% and 12.5% of the full equipment respectively, the performance is close to the ideal case. Using a changing link weight policy can improve performance greatly, when there are enough splitters and converters.

Extensions to P2MP RSVP-TE for VPN-specific state provisioning with fair resource sharing

Among the resource provisioning algorithms for the hose-based Virtual Private Network (VPN) Quality of Service (QoS), VPN-specific state provisioning allows the service provider to obtain highest resource multiplexing gains. In this paper, we show that the existing resource reservation protocols proposed for the Internet are not appropriate for the VPN-specific state provisioning. Furthermore, since the VPN-specific state provisioning makes the reserved resources to be randomly shared by the sites belonging to the same VPN, a site generating heavy traffic may unfairly dominate the resources reserved for the VPN. We propose extensions to an existing resource reservation protocol proposed for the Internet, i.e., P2MP RSVP-TE (Point-to-Multipoint Resource Reservation Protocol-Traffic Engineering), for the resource reservation of VPN-specific state provisioning. The proposed extensions also enable the fair usage of reserved resources among the users of a VPN that is provisioned by the VPN-specific state. Through simulation experiments, the effects of deploying a fair usage mechanism into the resource reservation of VPN-specific state provisioning is presented.

Performance analysis of optical multicast in a new switching structure

The emergence of new services demands multicast function in optical network. Because of the high cost and complex architecture of multicast capable (MC) node, splitter-sharing switch structure is introduced in which the light splitters are shared by all input signals. To accommodate to this situation, by extending resource ReSerVation protocol-traffic engineering (RSVP-TE) and open shortest path first-traffic engineering (OSPF-TE), a new optical multicast mechanism is provided and the signaling flow and its finite state machine model are given. At the same time, a multicast routing algorithm in splitter-sharing optical network and a changing link weight policy to balance network traffic are proposed. Simulations in NSFNET show no matter with or without wavelength converters, when the number of splitters is 25% of that demanded by traditional MC nodes, the multicast performance has been close to the ideal circumstance. Wavelength converters and changing link weight help much in improving the traffic performance when the number of splitters is adequate.

Design of a high-performance RSVP-TE hardware signaling accelerator

Signaling protocols, primarily used to set up and teardown connections, are essential in connection-oriented networks. Up to now, signaling protocols are mostly implemented in software for two reasons: complexity and the requirement for flexibility. Adversely, the price paid is in performance. Software implementations of signaling protocols are rarely capable of handling over 1000 calls/s. Corresponding call setup delays per switch are in the order of milliseconds. To improve performance for high-speed networks, we implemented a subset of the resource reservation protocol-traffic engineering signaling protocol in reconfigurable field programmable gate array hardware. Our implementation demonstrates the feasibility of 1000x speedup vis-a/spl grave/-vis software implementations. The impact of this work is far-reaching in that it enables connection-oriented networks to support new applications that require rate guarantees but have short call holding times.

The private user network interface - a GMPLS-compliant signaling interface for overlay-based multilayer networks

Feature Issue on Next-Generation WDM Network Design and Routing (WDMN). To address the integration of [IP/MPLS (multiprotocol label-switching)] packet and (optical) transport networks, the Optical Internetworking Forum (OIF) has defined a user-to-network interface (UNI) for overlay networks: the OIF UNI version 1.0, also referred to as the Public UNI. However, since its implementation agreement specification, it has become clear that this UNI--based on OIF-specific extensions to the generalized MPLS (GMPLS) protocols--will not be able to meet the future requirements of some operational environments. Hence a flexible, extensible, and fully GMPLS-compliant UNI is being defined at the Internet Engineering Task Force (IETF): the Private UNI (aka GMPLS for overlay networks). The Private UNI enhances the interaction between the packet and transport network control planes of a multilayer network architecture. This interface is particularly suitable for a control-plane interconnection model in which the equipment belongs to a common administrative entity (i.e., a single carrier environment). Signaling sessions through the Private UNI are used to invoke two main services that require constructive coordination between the network layers: provisioning and network recovery. Here we present the Private UNI specific GMPLS resource reservation protocol-traffic engineering (RSVP-TE) extensions in support of these services in IP/MPLS over SONET/SDH (synchronous optical network/synchronous digital hierarchy) GMPLS multilayer networks and illustrate how Private UNI signaling enhances coordination in multilayer network recovery.