IAX协议是一种应用于Asterisk IP PBX的VOIP协议,同其它VOIP协议(如H.323协议和SIP协议)相比较,IAX在信令控制、媒体流传输和防火墙/NAT穿越上都了良好的性能。IAX协议正在成为潜在的VOIP协议的标准而被大家广泛接受。SIP协议和H.323协...IAX协议是一种应用于Asterisk IP PBX的VOIP协议,同其它VOIP协议(如H.323协议和SIP协议)相比较,IAX在信令控制、媒体流传输和防火墙/NAT穿越上都了良好的性能。IAX协议正在成为潜在的VOIP协议的标准而被大家广泛接受。SIP协议和H.323协议是目前应用最为广泛的协议,在对SIP协议、H.323协议的构建VOIP网络的研究基础上,结合IAX协议的特点,提出了用IAX协议部署VOIP网络的模型。展开更多
伴随下一代网络(Next generation network,NGN)的核心技术软交换的发展,语音通信控制系统将由电路交换的语音系统向以软交换为核心的语音通信控制系统演变。文章针对网络电话VoIP(Voice over internet protocol)语音系统的组成,提出并...伴随下一代网络(Next generation network,NGN)的核心技术软交换的发展,语音通信控制系统将由电路交换的语音系统向以软交换为核心的语音通信控制系统演变。文章针对网络电话VoIP(Voice over internet protocol)语音系统的组成,提出并分析基于Asterisk和FreePBX实现服务器的架构,对VoIP软电话终端拟采用的协议栈和实现方式进行设计,以期提供一种实现VoIP语音系统的方式。展开更多
VoIP(Voice over Internet Protocol)是一种以IP电话为主,并推出相应的增值业务的技术。通过对VoIP系统的分析,介绍了如何利用开源软件Trixbox来构建一个企业内部的VoIP通信网络。从而实现将数据网与电话网二网合一,不仅极大的提高企业...VoIP(Voice over Internet Protocol)是一种以IP电话为主,并推出相应的增值业务的技术。通过对VoIP系统的分析,介绍了如何利用开源软件Trixbox来构建一个企业内部的VoIP通信网络。从而实现将数据网与电话网二网合一,不仅极大的提高企业内部协同工作的效率,而且节省大量的费用。展开更多
The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instant...The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instanton vacuum of QCD, where both the space-like region as well as the time-like one of the momenta for the virtual photons are investigated. In addition, the problem about the consistency between the two different definitions of the transverse photon wavefunction with chiral-odd Dirac structure, σμν, has been considered, and proven to be true at the leading order by means of the sum rule method. A brief discussion of the dependence of the transverse light-cone photon wavefunction φγ⊥（u, p2） and its coupling, Fγ^⊥（u, P2） to the corresponding quark-antiquark current with respect to p^2, and that about the end-point behaviour of the transverse photon wavefunction is given.展开更多
文摘IAX协议是一种应用于Asterisk IP PBX的VOIP协议,同其它VOIP协议(如H.323协议和SIP协议)相比较,IAX在信令控制、媒体流传输和防火墙/NAT穿越上都了良好的性能。IAX协议正在成为潜在的VOIP协议的标准而被大家广泛接受。SIP协议和H.323协议是目前应用最为广泛的协议,在对SIP协议、H.323协议的构建VOIP网络的研究基础上,结合IAX协议的特点,提出了用IAX协议部署VOIP网络的模型。
文摘伴随下一代网络(Next generation network,NGN)的核心技术软交换的发展,语音通信控制系统将由电路交换的语音系统向以软交换为核心的语音通信控制系统演变。文章针对网络电话VoIP(Voice over internet protocol)语音系统的组成,提出并分析基于Asterisk和FreePBX实现服务器的架构,对VoIP软电话终端拟采用的协议栈和实现方式进行设计,以期提供一种实现VoIP语音系统的方式。
文摘VoIP(Voice over Internet Protocol)是一种以IP电话为主,并推出相应的增值业务的技术。通过对VoIP系统的分析,介绍了如何利用开源软件Trixbox来构建一个企业内部的VoIP通信网络。从而实现将数据网与电话网二网合一,不仅极大的提高企业内部协同工作的效率,而且节省大量的费用。
基金Supported by the National Natural Science Foundation of China under Grant No 10075036, the BEPC National Laboratory Project R＆D and BES Collaboration Research Foundation.
文摘The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instanton vacuum of QCD, where both the space-like region as well as the time-like one of the momenta for the virtual photons are investigated. In addition, the problem about the consistency between the two different definitions of the transverse photon wavefunction with chiral-odd Dirac structure, σμν, has been considered, and proven to be true at the leading order by means of the sum rule method. A brief discussion of the dependence of the transverse light-cone photon wavefunction φγ⊥（u, p2） and its coupling, Fγ^⊥（u, P2） to the corresponding quark-antiquark current with respect to p^2, and that about the end-point behaviour of the transverse photon wavefunction is given.
