In this work, Session Initiation Protocol model is established by using Timed Colored Petri Nets (TCPN). SIP (Session Initiation Protocol) is a protocol developed to assist in providing advanced telephony services acr...In this work, Session Initiation Protocol model is established by using Timed Colored Petri Nets (TCPN). SIP (Session Initiation Protocol) is a protocol developed to assist in providing advanced telephony services across the Internet. The Session Initiation Protocol (SIP) has become the quasi-standard for Voiceover-Internet Protocol (VoIP) communications. SIP is based on a client–server infrastructure in which user agents represent the end-terminals as clients, proxy servers handle SIP message routing between the user agents, and registrar servers store the client’s contact information into a location service. By use of timed color set and useful time attributes in tokens defined in CPN tools, timer and time-related problems of SIP are modeled and analyzed. Timer is an important part for SIP, especially the INVITE transaction.展开更多
Application layer multicast (ALM) has been widely applied in Internet, as a substitute for IP multicast. However, it causes network load to increase because it adopts unicast in data transmission, which limits the app...Application layer multicast (ALM) has been widely applied in Internet, as a substitute for IP multicast. However, it causes network load to increase because it adopts unicast in data transmission, which limits the application. In this article, in order to improve the ALM performance in P2P-SIP network, an ALM model was proposed which reduced network load via merging messages in concast mode. Finally network simulations prove that this model has better benefit on single node load and average network load. Therefore, it is suitable for streaming media service in P2P-SIP Network.展开更多
Decentralized peer-to-peer session initiation protocol (P2PSIP) provides the same services as legacy SIPs such as IMS. However, in relatively open network, the requirement for route efficiency in a complex environme...Decentralized peer-to-peer session initiation protocol (P2PSIP) provides the same services as legacy SIPs such as IMS. However, in relatively open network, the requirement for route efficiency in a complex environment brings about undefined problems. To deploy a controllable P2PSIP network, perfect mechanisms have to be appended, especially in QoS, security, and management. Several proposals for QoS, network address translation (NAT), and interworking have been put forward. In this paper, we propose an integrated architecture for a P2PSIP system as well as a proactive intelligent routing scheme on the media plane used in system. Implementation and simulation show that our solution is suitable for operation and management.展开更多
Two common kinds of security mechanisms used in session initial protocol (S1P) are analyzed. An improved HTTP digest authentication scheme is put forward based on the existing SIP authentication theories. This mecha...Two common kinds of security mechanisms used in session initial protocol (S1P) are analyzed. An improved HTTP digest authentication scheme is put forward based on the existing SIP authentication theories. This mechanism is combined with the merits of the HTTP digest authentication and the public key encryption, so the communicating parties complete two-way authentication and public key exchange in pre-calling, and the session key can be randomly generated in post-calling. The mixture of security encryption mechanism with public key encryption and symmetric-key encryption algorithm can ensure the security for network communication data. The emulation of the scheme is verified, and the security analysis is conducted in the end. The researches show that the simulations efficiency of this method is about 78% of HTTP's, and it can prevent four kinds of attacks including impersonating a server, offline password guessing attacks, relay-attack, and session monitoring.展开更多
Conference control is a very important core part to compose a completeInternet multimedia conference system and has been a hot research area over the years, but there arecurrently no -widely accepted robust and scalab...Conference control is a very important core part to compose a completeInternet multimedia conference system and has been a hot research area over the years, but there arecurrently no -widely accepted robust and scalable solutions and standards. This paper proposes acomponent-based conference control model for loosely coupled sessions in which media applicationscan collaborate with a Session Controller (SC) to provide the conference control. A SC prototype hasbeen built.展开更多
The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implem...The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implementations have been developed and deployed. How to guarantee the conformance of those SIP implementations is the key point of interconnection and interoperation among them. This paper proposes the test method and architecture for the SIP protocol based on the IPv6 tester system. Tree and tabular combined notation (TTCN-2) is adopted to describe the test suite. With an enhanced reference implementation, the data-processing ability to the original test system has been greatly improved. In the following test practices, some errors have been found in the SIP entities under test. It is proved that the proposed test method and architecture are effective to verify the conformance of the SIP entities, and the result of the conformance test may provide helpful reference to the development of SIP products.展开更多
文摘In this work, Session Initiation Protocol model is established by using Timed Colored Petri Nets (TCPN). SIP (Session Initiation Protocol) is a protocol developed to assist in providing advanced telephony services across the Internet. The Session Initiation Protocol (SIP) has become the quasi-standard for Voiceover-Internet Protocol (VoIP) communications. SIP is based on a client–server infrastructure in which user agents represent the end-terminals as clients, proxy servers handle SIP message routing between the user agents, and registrar servers store the client’s contact information into a location service. By use of timed color set and useful time attributes in tokens defined in CPN tools, timer and time-related problems of SIP are modeled and analyzed. Timer is an important part for SIP, especially the INVITE transaction.
基金National Natural Science Foundation of China ( No. 71171045 ) Fundamental Research Funds for the Central Universities,China ( No. 11D10413,No. 11D10417,No. 12D10416 ) Donghua University Research Foundation for Young Teacher,China ( No. 104-10-0044010 )
文摘Application layer multicast (ALM) has been widely applied in Internet, as a substitute for IP multicast. However, it causes network load to increase because it adopts unicast in data transmission, which limits the application. In this article, in order to improve the ALM performance in P2P-SIP network, an ALM model was proposed which reduced network load via merging messages in concast mode. Finally network simulations prove that this model has better benefit on single node load and average network load. Therefore, it is suitable for streaming media service in P2P-SIP Network.
基金funded by the Next Generation Bandwidth Wireless Mobile Communication Network Programa Key National Science and Technology Specific Project sponsored by MIIT of China, under Grant No. 2010ZX03004-001
文摘Decentralized peer-to-peer session initiation protocol (P2PSIP) provides the same services as legacy SIPs such as IMS. However, in relatively open network, the requirement for route efficiency in a complex environment brings about undefined problems. To deploy a controllable P2PSIP network, perfect mechanisms have to be appended, especially in QoS, security, and management. Several proposals for QoS, network address translation (NAT), and interworking have been put forward. In this paper, we propose an integrated architecture for a P2PSIP system as well as a proactive intelligent routing scheme on the media plane used in system. Implementation and simulation show that our solution is suitable for operation and management.
基金Supported by the Central University Basic Research Special Fund Operating Expenses(2011ZM0033)
文摘Two common kinds of security mechanisms used in session initial protocol (S1P) are analyzed. An improved HTTP digest authentication scheme is put forward based on the existing SIP authentication theories. This mechanism is combined with the merits of the HTTP digest authentication and the public key encryption, so the communicating parties complete two-way authentication and public key exchange in pre-calling, and the session key can be randomly generated in post-calling. The mixture of security encryption mechanism with public key encryption and symmetric-key encryption algorithm can ensure the security for network communication data. The emulation of the scheme is verified, and the security analysis is conducted in the end. The researches show that the simulations efficiency of this method is about 78% of HTTP's, and it can prevent four kinds of attacks including impersonating a server, offline password guessing attacks, relay-attack, and session monitoring.
文摘Conference control is a very important core part to compose a completeInternet multimedia conference system and has been a hot research area over the years, but there arecurrently no -widely accepted robust and scalable solutions and standards. This paper proposes acomponent-based conference control model for loosely coupled sessions in which media applicationscan collaborate with a Session Controller (SC) to provide the conference control. A SC prototype hasbeen built.
基金the National Natural Science Foundation of China (No. 60572082)
文摘The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implementations have been developed and deployed. How to guarantee the conformance of those SIP implementations is the key point of interconnection and interoperation among them. This paper proposes the test method and architecture for the SIP protocol based on the IPv6 tester system. Tree and tabular combined notation (TTCN-2) is adopted to describe the test suite. With an enhanced reference implementation, the data-processing ability to the original test system has been greatly improved. In the following test practices, some errors have been found in the SIP entities under test. It is proved that the proposed test method and architecture are effective to verify the conformance of the SIP entities, and the result of the conformance test may provide helpful reference to the development of SIP products.