ipsec vpi
VPI：虚拟路径标识符 (VPI: Virtual Path Identifier)
VPI is an abbreviation of a Virtual Path Identifier. In the header of an ATM cell, it is a field of 8-bit. To set up a virtual network path for an asynchronous transfer approach, it functions as a data communication identifier.
VPI是Virtual Path Identifier的缩写 。 在ATM信元的标题中，它是8位字段。 为了为异步传输方法设置虚拟网络路径，它充当数据通信标识符。
Image source: https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcRjYSedRfSbLXYqBG42CICTbQ8Y4alVZsq3pkFYDJIk6zJFjHUV
图片来源：https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcRjYSedRfSbLXYqBG42CICTbQ8Y4alVZsq3pkFYDJIk6zJFjHUV
Commonly, ATM cells pass through ATM switches and to spot the path or destination of the cell the VPI is used with VCI. VPI appraises the switches about the path of the cell as the cell makes a journey through the network of ATM. In Frame Relay, the role of operations of VPI is similar to the role of operations of DLCI.
通常，ATM信元会通过ATM交换机，以发现VPI与VCI一起使用的信元的路径或目的地。 当信元经过ATM网络时，VPI会评估有关信元路径的开关。 在帧中继中，VPI的作用类似于DLCI的作用。
The entire ATM cell switching network enabled by the association of VPIs works with virtual channel identifiers. Within the entire channel communication potential, ATM cells generate virtual circuits and paths which lead them to diverse networks. The virtual channel identifier alludes to the circuit/channel in use, at the same time VPI matches the suitable path to the preferred destination host.
通过VPI关联启用的整个ATM信元交换网络都可以与虚拟通道标识符一起使用。 在整个信道通信潜力内，ATM信元会生成虚拟电路和虚拟路径，从而将它们引向各种网络。 虚拟通道标识符暗示使用中的电路/通道，同时VPI匹配到首选目标主机的合适路径。
ATM cells allow direct and quick communication and also develop regularity and make available for use recognition at the same time organizing access control. A numeric recognition is prearranged to all the circuits and paths formed by the ATM switch; this numeric recognition is called as virtual channel identifiers and virtual path identifiers.
ATM单元可以进行直接和快速的通信，还可以发展规律性，并在组织访问控制的同时提供使用识别。 ATM交换机形成的所有电路和路径都预先设置了数字识别。 这种数字识别称为虚拟通道标识符和虚拟路径标识符。
Virtual Path: In the ATM header, the bandwidth of the communication route is reasonably classified into separate virtual paths and by using the VPI they are identified. Every virtual path is allotted a fixed quantity of bandwidth. Dynamic variation in the bandwidths of Virtual paths does not occur ahead of what has been allotted.
虚拟路径 ：在ATM标头中，将通信路由的带宽合理地划分为单独的虚拟路径，并通过使用VPI对其进行标识。 每个虚拟路径都分配有固定数量的带宽。 虚拟路径带宽的动态变化不会在分配之前发生。
Virtual Connection: In the ATM header, the bandwidth of a virtual path is reasonably classified into separate virtual channels by using a virtual channel identifier. Virtual channels share the bandwidth inside a virtual path dynamically which is not similar to virtual paths.
虚拟连接 ：在ATM标头中，通过使用虚拟通道标识符将虚拟路径的带宽合理地划分为单独的虚拟通道。 虚拟通道动态共享虚拟路径内部的带宽，该带宽与虚拟路径不同。
优点 (Advantages)
- It makes a simpler network design. 它使网络设计更加简单。
- It enhances network performance and consistency. 它增强了网络性能和一致性。
- It diminishes processing and setup timings of small connections. 它减少了小型连接的处理和设置时间。
- It enhances the services of the network. 它增强了网络的服务。
Virtual Channel Connection Uses
虚拟通道连接用途
- It is used between end users. 在最终用户之间使用。
- It can support end-to-end user data or manage signaling between two users. 它可以支持端到端用户数据或管理两个用户之间的信令。
- It is used between an end user and a network entity. 它在最终用户和网络实体之间使用。
- It is used for user-to-network control signaling. 它用于用户到网络的控制信令。
虚拟路径/虚拟通道特征 (Virtual Path/Virtual Channel Characteristics)
- Quality of service. 服务质量。
- Specified by parameters. 由参数指定。
- Switched and semi-permanent virtual channel connections. 交换和半永久虚拟通道连接。
- Cell sequence of integrity. 信元序列的完整性。
翻译自: https://www.includehelp.com/dictionary/vpi-full-form.aspx
ipsec vpi