PIM-SM(Protocol Independent Multicast-Sparse Mode) is a main multicast routing pro-tocol in the IPv6(Internet Protocol version 6).It can use either a shared tree or a shortest path tree to deliver data packets,consequ...PIM-SM(Protocol Independent Multicast-Sparse Mode) is a main multicast routing pro-tocol in the IPv6(Internet Protocol version 6).It can use either a shared tree or a shortest path tree to deliver data packets,consequently the multicast IP lookup engine requires,in some cases,two searches to get a correct lookup result according to its multicast forwarding rule,and it may result in a new requirement of doubling the lookup speed of the lookup engine.The ordinary method to satisfy this requirement in TCAM(Ternary Content Addressable Memory) based lookup engines is to exploit parallelism among multiple TCAMs.However,traditional parallel methods always induce more re-sources and higher design difficulty.We propose in this paper a novel approach to solve this problem.By arranging multicast forwarding table in class sequence in TCAM and making full use of the intrinsic characteristic of the TCAM,our approach can get the right lookup result with just one search and a single TCAM,while keeping the hardware of lookup engine unchanged.Experimental results have shown that the approach make it possible to satisfy forwarding IPv6 multicast packets at the full link rate of 20 Gb/s with just one TCAM with the current TCAM chip.展开更多
Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-...Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.展开更多
On the basis of inner-system labeling signaling used in the integrated access system,a kind of inner-system labeling algorithm is introduced in this paper, and the fairness of the algorithm for each traffic stream in ...On the basis of inner-system labeling signaling used in the integrated access system,a kind of inner-system labeling algorithm is introduced in this paper, and the fairness of the algorithm for each traffic stream in the integrated-services is analyzed. The base of this algorithm is Class of Services (CoS), and each packet entering the relative independent area (an autonomous system) would be labeled according to the service type or Quality of Service (QoS) in demand,and be scheduled and managed within the system (the system can be enlarged if conforming to the same protocol). The experimental results show that each of the stream rate in the integratedservices would converge to a stable value if the rates of transmitting converge to that of the receiving exponentially, that is, the effective traffic of each stream would be fair.展开更多
基金Supported by the National High-Tech Research and De-velopment Plan of China (No. 2007AA01Z2a1)the Na-tional Grand Fundamental Research 973 Program of China (No. 2007CB307102)
文摘PIM-SM(Protocol Independent Multicast-Sparse Mode) is a main multicast routing pro-tocol in the IPv6(Internet Protocol version 6).It can use either a shared tree or a shortest path tree to deliver data packets,consequently the multicast IP lookup engine requires,in some cases,two searches to get a correct lookup result according to its multicast forwarding rule,and it may result in a new requirement of doubling the lookup speed of the lookup engine.The ordinary method to satisfy this requirement in TCAM(Ternary Content Addressable Memory) based lookup engines is to exploit parallelism among multiple TCAMs.However,traditional parallel methods always induce more re-sources and higher design difficulty.We propose in this paper a novel approach to solve this problem.By arranging multicast forwarding table in class sequence in TCAM and making full use of the intrinsic characteristic of the TCAM,our approach can get the right lookup result with just one search and a single TCAM,while keeping the hardware of lookup engine unchanged.Experimental results have shown that the approach make it possible to satisfy forwarding IPv6 multicast packets at the full link rate of 20 Gb/s with just one TCAM with the current TCAM chip.
基金Supported by National Basic Research and Development Program of China (2007CB307102)
文摘Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.
文摘On the basis of inner-system labeling signaling used in the integrated access system,a kind of inner-system labeling algorithm is introduced in this paper, and the fairness of the algorithm for each traffic stream in the integrated-services is analyzed. The base of this algorithm is Class of Services (CoS), and each packet entering the relative independent area (an autonomous system) would be labeled according to the service type or Quality of Service (QoS) in demand,and be scheduled and managed within the system (the system can be enlarged if conforming to the same protocol). The experimental results show that each of the stream rate in the integratedservices would converge to a stable value if the rates of transmitting converge to that of the receiving exponentially, that is, the effective traffic of each stream would be fair.
