P2P streaming application must realize network address translation (NAT) traversal. To handle low success ratio of the existing NAT traversal algorithm, UPnP-STUN (UPUN) and port-mapping sample estimation (PMSE)...P2P streaming application must realize network address translation (NAT) traversal. To handle low success ratio of the existing NAT traversal algorithm, UPnP-STUN (UPUN) and port-mapping sample estimation (PMSE) algorithm are recommended in this paper. UPUN is the combination of UPnP and STUN, and PMSE utilizes port mapping samples added by symmetric NAT for different sessions to estimate regularity of port mapping of symmetric NAT, which takes advantage of the Bernoulli law of large numbers. Besides, for the situation that both peers are behind NAT, and to handle heavy relay server load when many inner peers want to communicate with each other, a peer auxiliary-relay (PAR) algorithm is presented. PAR lets outer peers with sufficient bandwidth act as relay servers to alleviate pressure of real server, which could avoid NAT traversal failure caused by single point failure of relay server. Finally, experiments show that the proposed algorithms could improve the success ratio significantly for NAT traversal in P2P streaming application as well as improve P2P streaming application applicability.展开更多
A sequence of spherical zonal translation networks based on the Bochner-Riesz means of spherical harmonics and the Riesz means of Jacobi polynomials is introduced, and its degree of approximation is achieved. The resu...A sequence of spherical zonal translation networks based on the Bochner-Riesz means of spherical harmonics and the Riesz means of Jacobi polynomials is introduced, and its degree of approximation is achieved. The results obtained in the present paper actually imply that the approximation of zonal translation networks is convergent if the action functions have certain smoothness.展开更多
In the present paper, we find that the Bernstein-Durrmeyer operators, besides their better applications in approximation theory and some other fields, are good tools in constructing translation network. With the help ...In the present paper, we find that the Bernstein-Durrmeyer operators, besides their better applications in approximation theory and some other fields, are good tools in constructing translation network. With the help of the de la Vallée properties of the Bernstein-Durrmeyer operators a sequence of translation network operators is constructed and its degree of approximation is dealt.展开更多
Malicious attacks can be launched by misusing the network address translation technique as a camouflage.To mitigate such threats,network address translation identification is investigated to identify network address t...Malicious attacks can be launched by misusing the network address translation technique as a camouflage.To mitigate such threats,network address translation identification is investigated to identify network address translation devices and detect abnormal behaviors.However,existingmethods in this field are mainly developed for relatively small-scale networks and work in an offline manner,which cannot adapt to the real-time inference requirements in high-speed network scenarios.In this paper,we propose a flexible and efficient network address translation identification scheme based on actively measuring the distance of a round trip to a target with decremental time-tolive values.The basic intuition is that the incoming and outgoing traffic froma network address translation device usually experiences the different number of hops,which can be discovered by probing with dedicated time-to-live values.We explore a joint effort of parallel transmission,stateless probes,and flexible measuring reuse to accommodate the efficiency of the measuring process.We further accelerate statistical countingwith a new sublinear space data structure Bi-sketch.We implement a prototype and conduct real-world deployments with 1000 volunteers in 31 Chinese provinces,which is believed to bring insight for ground truth collection in this field.Experiments onmulti-sources datasets show that our proposal can achieve as high precision and recall as 95%with a traffic handling throughput of over 106 pps.展开更多
The transition from IPv4 to IPv6 is doomed to be a long process. The network Address translation (NAT) technology is used very popularly in IPv4 network to make up the shortage of network address. It is a desiderate...The transition from IPv4 to IPv6 is doomed to be a long process. The network Address translation (NAT) technology is used very popularly in IPv4 network to make up the shortage of network address. It is a desiderated problem to make the users behind NAT gateway to access to IPv6 networks. By studying the transition technology from IPv4 to IPv6 and introducing NAT technology in IPv6, a scenario is put forward through 6to4 tunnel The scenario is implemented and the gateway system's performance is analyzed.展开更多
This paper presents a survey of image synthesis and editing with Generative Adversarial Networks(GANs). GANs consist of two deep networks, a generator and a discriminator, which are trained in a competitive way. Due...This paper presents a survey of image synthesis and editing with Generative Adversarial Networks(GANs). GANs consist of two deep networks, a generator and a discriminator, which are trained in a competitive way. Due to the power of deep networks and the competitive training manner, GANs are capable of producing reasonable and realistic images, and have shown great capability in many image synthesis and editing applications.This paper surveys recent GAN papers regarding topics including, but not limited to, texture synthesis, image inpainting, image-to-image translation, and image editing.展开更多
End hopping is one of the good methods to defend against network attack,but has problems with network address translation(NAT) because packets sent from an unknown endpoint would be dropped by NAT.To avoid the dropp...End hopping is one of the good methods to defend against network attack,but has problems with network address translation(NAT) because packets sent from an unknown endpoint would be dropped by NAT.To avoid the dropping of packets,we propose a punching scheme:a client sends a punching packet to create mapping rules in NAT,so that the packets from the server would be able to pass through effectively with such rules.In this paper,some preliminaries and definitions are provided for building the model of end hopping.Then we discuss the main reason of such packet dropping and specify all the failure situations based on the model.What's more,we analyze how the punching scheme helps end hopping cross NAT.Finally,we validate the feasibility of this scheme with empirical results:if the client is behind a NAT and with punching scheme,the service rate increases to 100%.Therefore,our proposed scheme can greatly improve the performance of crossing NAT in end hopping with little security and computational overhead.展开更多
基金Supported by the Nat/onal Science and Technology Support Projects of China(No. 2008BAH28B04) and the National Natural Science Foundation of China _(No..60903218F0208) andthe National High Technology Research and Development Programme of China (No. 2008AA01A317)
文摘P2P streaming application must realize network address translation (NAT) traversal. To handle low success ratio of the existing NAT traversal algorithm, UPnP-STUN (UPUN) and port-mapping sample estimation (PMSE) algorithm are recommended in this paper. UPUN is the combination of UPnP and STUN, and PMSE utilizes port mapping samples added by symmetric NAT for different sessions to estimate regularity of port mapping of symmetric NAT, which takes advantage of the Bernoulli law of large numbers. Besides, for the situation that both peers are behind NAT, and to handle heavy relay server load when many inner peers want to communicate with each other, a peer auxiliary-relay (PAR) algorithm is presented. PAR lets outer peers with sufficient bandwidth act as relay servers to alleviate pressure of real server, which could avoid NAT traversal failure caused by single point failure of relay server. Finally, experiments show that the proposed algorithms could improve the success ratio significantly for NAT traversal in P2P streaming application as well as improve P2P streaming application applicability.
基金This research is supported (in part) by the National Natural Science Foundation of China (No. 10471130, 10371024) of China the Natural Science Foundation (Y640003) of Zhejiang Province and the Doctor Foundation (2004A620017) of Ningbo city.
文摘A sequence of spherical zonal translation networks based on the Bochner-Riesz means of spherical harmonics and the Riesz means of Jacobi polynomials is introduced, and its degree of approximation is achieved. The results obtained in the present paper actually imply that the approximation of zonal translation networks is convergent if the action functions have certain smoothness.
基金Supported by the NSF of P.R.China(10471130)the NSF of Zhejiang Province(Y604003)
文摘In the present paper, we find that the Bernstein-Durrmeyer operators, besides their better applications in approximation theory and some other fields, are good tools in constructing translation network. With the help of the de la Vallée properties of the Bernstein-Durrmeyer operators a sequence of translation network operators is constructed and its degree of approximation is dealt.
基金The work is supported by the National Key Research and Development Program of China(2018YFB1800202)the NUDT Research Grants(No.ZK19-38).
文摘Malicious attacks can be launched by misusing the network address translation technique as a camouflage.To mitigate such threats,network address translation identification is investigated to identify network address translation devices and detect abnormal behaviors.However,existingmethods in this field are mainly developed for relatively small-scale networks and work in an offline manner,which cannot adapt to the real-time inference requirements in high-speed network scenarios.In this paper,we propose a flexible and efficient network address translation identification scheme based on actively measuring the distance of a round trip to a target with decremental time-tolive values.The basic intuition is that the incoming and outgoing traffic froma network address translation device usually experiences the different number of hops,which can be discovered by probing with dedicated time-to-live values.We explore a joint effort of parallel transmission,stateless probes,and flexible measuring reuse to accommodate the efficiency of the measuring process.We further accelerate statistical countingwith a new sublinear space data structure Bi-sketch.We implement a prototype and conduct real-world deployments with 1000 volunteers in 31 Chinese provinces,which is believed to bring insight for ground truth collection in this field.Experiments onmulti-sources datasets show that our proposal can achieve as high precision and recall as 95%with a traffic handling throughput of over 106 pps.
文摘The transition from IPv4 to IPv6 is doomed to be a long process. The network Address translation (NAT) technology is used very popularly in IPv4 network to make up the shortage of network address. It is a desiderated problem to make the users behind NAT gateway to access to IPv6 networks. By studying the transition technology from IPv4 to IPv6 and introducing NAT technology in IPv6, a scenario is put forward through 6to4 tunnel The scenario is implemented and the gateway system's performance is analyzed.
基金supported by the National Key Technology R&D Program(No.2016YFB1001402)the National Natural Science Foundation of China(No.61521002)+2 种基金the Joint NSFC-ISF Research Program(No.61561146393)Research Grant of Beijing Higher Institution Engineering Research Center and Tsinghua-Tencent Joint Laboratory for Internet Innovation Technologysupported by the EPSRC CDE(No.EP/L016540/1)
文摘This paper presents a survey of image synthesis and editing with Generative Adversarial Networks(GANs). GANs consist of two deep networks, a generator and a discriminator, which are trained in a competitive way. Due to the power of deep networks and the competitive training manner, GANs are capable of producing reasonable and realistic images, and have shown great capability in many image synthesis and editing applications.This paper surveys recent GAN papers regarding topics including, but not limited to, texture synthesis, image inpainting, image-to-image translation, and image editing.
基金Supported by the National Natural Science Foundation of China (60973141,61272423)the Specialized Research Fund for the Doctoral Program of Higher Education of China (20100031110030)the Funds of Key Lab of Fujian Province University Network Security and Cryptology (2011004)
文摘End hopping is one of the good methods to defend against network attack,but has problems with network address translation(NAT) because packets sent from an unknown endpoint would be dropped by NAT.To avoid the dropping of packets,we propose a punching scheme:a client sends a punching packet to create mapping rules in NAT,so that the packets from the server would be able to pass through effectively with such rules.In this paper,some preliminaries and definitions are provided for building the model of end hopping.Then we discuss the main reason of such packet dropping and specify all the failure situations based on the model.What's more,we analyze how the punching scheme helps end hopping cross NAT.Finally,we validate the feasibility of this scheme with empirical results:if the client is behind a NAT and with punching scheme,the service rate increases to 100%.Therefore,our proposed scheme can greatly improve the performance of crossing NAT in end hopping with little security and computational overhead.