A new coarse-grained differentiated least interference routing algorithm(CDLI) with DiffServ-Aware was presented.This algorithm is composed of off-line and on-line stages,taking into account both real-time traffic and...A new coarse-grained differentiated least interference routing algorithm(CDLI) with DiffServ-Aware was presented.This algorithm is composed of off-line and on-line stages,taking into account both real-time traffic and best-effort traffic.Off-line stage is to determine the shortest path set disjointed path(DP) database for real-time traffic,and to identify link critical value by traffic profile information of real-time traffic and DP database.On-line stage is at first to select route in the DP database for real-time traffic,if there is no path to meet the needs,the dynamic routing will be operated.On-line routing algorithm chooses the relatively short path for real-time traffic to meet their bandwidth requirements,and for best-effort traffic it chooses a lighter load path.The simulation results show that compared with the dynamic online routing algorithm(DORA) and constrained shortest path first(CSPF) algorithm,the new algorithm can significantly improve network throughput and reduce the average path length of real-time traffic.This guarantees quality of service(QoS) of real-time traffic while improving the utilization of network resources.展开更多
A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimi...A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.展开更多
The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone spac...The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone space, dispersion compensation and coupler split ratio, are studied by numerical simulation. The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.展开更多
This paper evaluates the performance of Internet Protocol Security (IPSec) based Multiprotocol Label Switching (MPLS) virtual private network (VPN) in a small to medium sized organization. The demand for security in d...This paper evaluates the performance of Internet Protocol Security (IPSec) based Multiprotocol Label Switching (MPLS) virtual private network (VPN) in a small to medium sized organization. The demand for security in data networks has been increasing owing to the high cyber attacks and potential risks associated with networks spread over distant geographical locations. The MPLS networks ride on the public network backbone that is porous and highly susceptible to attacks and so the need for reliable security mechanisms to be part of the deployment plan. The evaluation criteria concentrated on Voice over Internet Protocol (VoIP) and Video conferencing with keen interest in jitter, end to end delivery and general data flow. This study used both structured questionnaire and observation methods. The structured questionnaire was administered to a group of 70 VPN users in a company. This provided the study with precise responses. The observation method was used in data simulations using OPNET Version 14.5 Simulation software. The results show that the IPSec features increase the size of data packets by approximately 9.98% translating into approximately 90.02% effectiveness. The tests showed that the performance metrics are all well within the recommended standards. The IPSec Based MPLS Virtual private network is more stable and secure than one without IPSec.展开更多
Optimized are the label extinction ratio and dispersion compensation of an optical label switching transmission system,which employs 40-Gb/s return to zero differential phase shift keying(RZ-DPSK)payload labeled with ...Optimized are the label extinction ratio and dispersion compensation of an optical label switching transmission system,which employs 40-Gb/s return to zero differential phase shift keying(RZ-DPSK)payload labeled with 622-Mb/s amplitude shift keying(ASK)control data.In our scheme,the receiver sensitivities of payload and label achieves-27.8dBm and-33.5dBm,respectively.After transmitted over 40km,60km and 80km single mode fiber(SMF)(with dispersion compensation)respectively,the payload can be recovered with no power penalty,while the label can be recovered with less than 2dB penalty.展开更多
Implementing QoS, one of the eternal research subjects, on Internet has been attracting a lot of attentions although several schemes are already available. This letter proposes a new service architecture-Scalable Tri-...Implementing QoS, one of the eternal research subjects, on Internet has been attracting a lot of attentions although several schemes are already available. This letter proposes a new service architecture-Scalable Tri-tier Service Architecture (STSA) and a fast label switching scheme, which can reduce the overhead of signaling and suit the applications of access demand for a great number of end users with QoS guarantee. Also presented in the letter is an implementation of STSA in MPLS scenario.展开更多
Proposed is a novel optical code(OC) label switching scheme in which an optical label is constructed by multiple parallel optical codes.The performances of splitting loss and BER are simulated and analyzed.Simulation ...Proposed is a novel optical code(OC) label switching scheme in which an optical label is constructed by multiple parallel optical codes.The performances of splitting loss and BER are simulated and analyzed.Simulation results show that the proposed label can be correctly recognized to perform packet switching.Compared with reported schemes using one OC as a label,the splitting loss in our proposal is lowered.展开更多
Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying（RZ-DPSK） payload labeled with 2.5 Gbit/s...Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying（RZ-DPSK） payload labeled with 2.5 Gbit/s on-off keying（OOK） signal based on the optical carrier suppression and separation（OCSS） techniq ue, In the system, proposed are the receiver sensi ti vity oS payload and label, achieving -- 32. 4 dBm and --38.5 dBm, respectively. Using the optimal dispersion compensation scheme, after transmitted over 160 km and 320 km SMF respectively, the label can be recovered without power penalty, while the payload can be recovered with less than 2 dB and 5 dB penalty, respectively.展开更多
The rapid development of network raise the role of WAN. As a large-scale backbone network, the failure of network components can lead to huge loss of data and revenue. How to improve the data switching speed and Quali...The rapid development of network raise the role of WAN. As a large-scale backbone network, the failure of network components can lead to huge loss of data and revenue. How to improve the data switching speed and Quality of Service of network data is more and more important problem which Internet Server Provides cared. Multi-Protocol Lable Switching （MPLS） is a new WAN technology which is currently being standardized by IETF. This paper analysise the architecture of MPLS and describe the mechanism of label switching protocol. In addition, this study analyses the encapsulation of data packet at the Label Switching Routers which is on the boundary of MPLS network. A Label Switching Path （LSP） is built by Label Distribute Protocol in core network. A conclution of ＂one time routed, more times switching＂ routed was reached.展开更多
We investigate prime labeling for some graphs resulted from switching of a vertex. We discuss switching invariance of some prime graphs and prove that the graphs obtained by switching of a vertex in Pn and K1,n admit ...We investigate prime labeling for some graphs resulted from switching of a vertex. We discuss switching invariance of some prime graphs and prove that the graphs obtained by switching of a vertex in Pn and K1,n admit prime labeling. Moreover we discuss prime labeling for the graph obtained by switching of vertex in wheel Wn.展开更多
Multi-protocol label switching（MPLS） has the advantage of high efficiency in the second layer, which improves the performance of data packets routing. In this paper, a new structure to implement optical MPLS is prop...Multi-protocol label switching（MPLS） has the advantage of high efficiency in the second layer, which improves the performance of data packets routing. In this paper, a new structure to implement optical MPLS is proposed. We construct a code family for spectral-amplitude coding（SAC） labels in the optical MPLS networks. SAC labels are suitable for optical packet switching because they can be constructed and recognized quickly at each router. We use the label stacking to provide hierarchical routing to avoid swapping labels at each forwarding node and reduce system complexity. However, the phase-induced intensity noise（PIIN） appears due to the incoherent property of the light source when the stacked labels set makes the correlation decoding with the local node label,which degrades system performance.展开更多
This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier （SOA） with a length of about 1.5 mm to optical label switching network based on c...This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier （SOA） with a length of about 1.5 mm to optical label switching network based on combined frequency shift keying （FSK）-intensiy modulation （IM）/optical label-packet modulation to overcome the dispersion limitation of fiber. The 155 Mb/s-10 Gb/s combined FSK/IM signal is experimentally transmitted over a 100 km standard single mode fiber. 10^-10 and 10^-9 BER （bit error ratio）, or even better, is achieved for the FSK label and IM packet, respectively. The -19 dB power conversion efficiency is obtained for -1 nm wavelength detuning.展开更多
In the present work we investigate some classes of graphs and disjoint union of some classes of graphs which admit prime labeling. We also investigate prime labeling of a graph obtained by identifying two vertices of ...In the present work we investigate some classes of graphs and disjoint union of some classes of graphs which admit prime labeling. We also investigate prime labeling of a graph obtained by identifying two vertices of two graphs. We also investigate prime labeling of a graph obtained by identifying two edges of two graphs. Prime labeling of a prism graph is also discussed. We show that a wheel graph of odd order is switching invariant. A necessary and sufficient condition for the complement of Wn to be a prime graph is investigated.展开更多
We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label...We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor （EOF） and bit-error rate （BER） at 10 9 as a function of the received optical power （ROP） and the optical signal to noise ratio （OSNR）. The payload could well be demodulated after 900 km at a bit error rate of 10-3 using forward error correction （FEC）.展开更多
基金Project(2003AA781011) supported by the National High-Tech Research and Development of Program of China Project(20072022) supported by Science and Technology Foundation of Liaoning Province,China
文摘A new coarse-grained differentiated least interference routing algorithm(CDLI) with DiffServ-Aware was presented.This algorithm is composed of off-line and on-line stages,taking into account both real-time traffic and best-effort traffic.Off-line stage is to determine the shortest path set disjointed path(DP) database for real-time traffic,and to identify link critical value by traffic profile information of real-time traffic and DP database.On-line stage is at first to select route in the DP database for real-time traffic,if there is no path to meet the needs,the dynamic routing will be operated.On-line routing algorithm chooses the relatively short path for real-time traffic to meet their bandwidth requirements,and for best-effort traffic it chooses a lighter load path.The simulation results show that compared with the dynamic online routing algorithm(DORA) and constrained shortest path first(CSPF) algorithm,the new algorithm can significantly improve network throughput and reduce the average path length of real-time traffic.This guarantees quality of service(QoS) of real-time traffic while improving the utilization of network resources.
基金This work was supported by the National Natural Science Foundation of China (No10371097)Open Project of Com-putational Key Laboratory in Yunnan Provice
文摘A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.
基金supported by the National Natural Science Foundation of China(Grant No 60677004)the National High Technology Research and Development Program of China(Grant No 2007AA01Z260)+4 种基金The project is also supported by the Key Project of Chinese Ministry of Education(Grant No 107011)the Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks(UESTC)(Ministry of Education of China)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry of China)the Corporative Building Project of Beijing Educational Committee(Grant No XK100130737)the Program for New Century Excellent Talents in University of China(Grant No NECT-07-0111)
文摘The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone space, dispersion compensation and coupler split ratio, are studied by numerical simulation. The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.
文摘This paper evaluates the performance of Internet Protocol Security (IPSec) based Multiprotocol Label Switching (MPLS) virtual private network (VPN) in a small to medium sized organization. The demand for security in data networks has been increasing owing to the high cyber attacks and potential risks associated with networks spread over distant geographical locations. The MPLS networks ride on the public network backbone that is porous and highly susceptible to attacks and so the need for reliable security mechanisms to be part of the deployment plan. The evaluation criteria concentrated on Voice over Internet Protocol (VoIP) and Video conferencing with keen interest in jitter, end to end delivery and general data flow. This study used both structured questionnaire and observation methods. The structured questionnaire was administered to a group of 70 VPN users in a company. This provided the study with precise responses. The observation method was used in data simulations using OPNET Version 14.5 Simulation software. The results show that the IPSec features increase the size of data packets by approximately 9.98% translating into approximately 90.02% effectiveness. The tests showed that the performance metrics are all well within the recommended standards. The IPSec Based MPLS Virtual private network is more stable and secure than one without IPSec.
基金National Natural Science Foundation of China(60677004)National"863"Program Project(2007AA01Z260)+1 种基金Key Project of Chinese Ministry of Education(107011)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Optimized are the label extinction ratio and dispersion compensation of an optical label switching transmission system,which employs 40-Gb/s return to zero differential phase shift keying(RZ-DPSK)payload labeled with 622-Mb/s amplitude shift keying(ASK)control data.In our scheme,the receiver sensitivities of payload and label achieves-27.8dBm and-33.5dBm,respectively.After transmitted over 40km,60km and 80km single mode fiber(SMF)(with dispersion compensation)respectively,the payload can be recovered with no power penalty,while the label can be recovered with less than 2dB penalty.
文摘Implementing QoS, one of the eternal research subjects, on Internet has been attracting a lot of attentions although several schemes are already available. This letter proposes a new service architecture-Scalable Tri-tier Service Architecture (STSA) and a fast label switching scheme, which can reduce the overhead of signaling and suit the applications of access demand for a great number of end users with QoS guarantee. Also presented in the letter is an implementation of STSA in MPLS scenario.
基金National Natural Science Foundation of China(60577045 and 60677004)Doctoral Subject Foundation,State Education Ministry(20050013002)+1 种基金Program for New Century Excellent Talents in University( NECT-07 -0111)Scientific Research Foundation for the Returned Overseas Chinese Scholars,StateEducation Ministry
文摘Proposed is a novel optical code(OC) label switching scheme in which an optical label is constructed by multiple parallel optical codes.The performances of splitting loss and BER are simulated and analyzed.Simulation results show that the proposed label can be correctly recognized to perform packet switching.Compared with reported schemes using one OC as a label,the splitting loss in our proposal is lowered.
基金National Natural Science Foundation of China(60677004)National High Technology"863"Research and Development Program of China(2007AA01Z260)+4 种基金Key Project of Chinese Ministry of Education(107011)Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks(Ministry of Education)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry)the Corporative Building Project of Beijing Educational Committee(XK100130737)Program for New Century Excellent Talents in University of China( NECT-07-0111)
文摘Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying（RZ-DPSK） payload labeled with 2.5 Gbit/s on-off keying（OOK） signal based on the optical carrier suppression and separation（OCSS） techniq ue, In the system, proposed are the receiver sensi ti vity oS payload and label, achieving -- 32. 4 dBm and --38.5 dBm, respectively. Using the optimal dispersion compensation scheme, after transmitted over 160 km and 320 km SMF respectively, the label can be recovered without power penalty, while the payload can be recovered with less than 2 dB and 5 dB penalty, respectively.
文摘The rapid development of network raise the role of WAN. As a large-scale backbone network, the failure of network components can lead to huge loss of data and revenue. How to improve the data switching speed and Quality of Service of network data is more and more important problem which Internet Server Provides cared. Multi-Protocol Lable Switching （MPLS） is a new WAN technology which is currently being standardized by IETF. This paper analysise the architecture of MPLS and describe the mechanism of label switching protocol. In addition, this study analyses the encapsulation of data packet at the Label Switching Routers which is on the boundary of MPLS network. A Label Switching Path （LSP） is built by Label Distribute Protocol in core network. A conclution of ＂one time routed, more times switching＂ routed was reached.
文摘We investigate prime labeling for some graphs resulted from switching of a vertex. We discuss switching invariance of some prime graphs and prove that the graphs obtained by switching of a vertex in Pn and K1,n admit prime labeling. Moreover we discuss prime labeling for the graph obtained by switching of vertex in wheel Wn.
文摘Multi-protocol label switching（MPLS） has the advantage of high efficiency in the second layer, which improves the performance of data packets routing. In this paper, a new structure to implement optical MPLS is proposed. We construct a code family for spectral-amplitude coding（SAC） labels in the optical MPLS networks. SAC labels are suitable for optical packet switching because they can be constructed and recognized quickly at each router. We use the label stacking to provide hierarchical routing to avoid swapping labels at each forwarding node and reduce system complexity. However, the phase-induced intensity noise（PIIN） appears due to the incoherent property of the light source when the stacked labels set makes the correlation decoding with the local node label,which degrades system performance.
基金supported by National Natural Science Foundation of China (Grant No 60677004)National High Technology 863 Research and Development Program of China (Grant Nos 2007AA01Z260,2007AA03Z447 and 2009AA01Z220)+4 种基金Key Project of the Chinese Ministry of Education (Grant No 107011)Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks (UESTC) (Ministry of Education)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)the Corporative Building Project of Beijing Educational Committee (Grant NoXK100130737)Program for New Century Excellent Talents in University of China (Grant No NECT-07-0111)
文摘This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier （SOA） with a length of about 1.5 mm to optical label switching network based on combined frequency shift keying （FSK）-intensiy modulation （IM）/optical label-packet modulation to overcome the dispersion limitation of fiber. The 155 Mb/s-10 Gb/s combined FSK/IM signal is experimentally transmitted over a 100 km standard single mode fiber. 10^-10 and 10^-9 BER （bit error ratio）, or even better, is achieved for the FSK label and IM packet, respectively. The -19 dB power conversion efficiency is obtained for -1 nm wavelength detuning.
文摘In the present work we investigate some classes of graphs and disjoint union of some classes of graphs which admit prime labeling. We also investigate prime labeling of a graph obtained by identifying two vertices of two graphs. We also investigate prime labeling of a graph obtained by identifying two edges of two graphs. Prime labeling of a prism graph is also discussed. We show that a wheel graph of odd order is switching invariant. A necessary and sufficient condition for the complement of Wn to be a prime graph is investigated.
文摘We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor （EOF） and bit-error rate （BER） at 10 9 as a function of the received optical power （ROP） and the optical signal to noise ratio （OSNR）. The payload could well be demodulated after 900 km at a bit error rate of 10-3 using forward error correction （FEC）.
