Content deleted Content added
m Disambiguating links to Lag (link changed to Latency (engineering)) using DisamAssist. |
No edit summary |
||
| (6 intermediate revisions by 4 users not shown) | |||
Line 1:
{{Short description|Networking standard}}
{{Unreferenced|date=February 2024}}
The '''Virtual Interface Architecture''' ('''VIA''') is an abstract model of a user-level [[zero-copy]] [[computer network|network]], and is the basis for [[InfiniBand]], [[iWARP]] and [[RDMA over Converged Ethernet|RoCE]]. Created by [[Microsoft]], [[Intel]], and [[Compaq]], the original VIA sought to standardize the interface for high-performance network technologies known as [[System Area
Networks are a shared resource. With traditional network APIs such as the [[Berkeley sockets|Berkeley socket API]], the [[kernel (
One of the classic developments in computing systems is [[virtual memory]], a combination of hardware and software that creates the illusion of private memory for each process. In the same school of thought, a virtual network interface protected across process boundaries could be accessed at the user level. With this technology, the "consumer" manages its own buffers and communication schedule while the "provider" handles the protection.
Thus, the [[network interface controller|network interface card]] (NIC) provides a "private network" for a process, and a process is usually allowed to have multiple such networks. The virtual interface (VI) of VIA refers to this network and is merely the destination of the user's communication requests. Communication takes place over a pair of VIs, one on each of the processing nodes involved in the transmission. In "kernel-bypass" communication, the user manages its own buffers.
Another facet of traditional networks is that arriving data is placed in a pre-allocated buffer and then copied to the user-specified final destination. Copying large messages can take a long time, and so eliminating this step is beneficial. Another classic development in computing systems is [[direct memory access]] (DMA), in which a device can access main memory directly while the CPU is free to perform other tasks.
In a network with "remote direct memory access" ([[Remote direct memory access|RDMA]]), the sending NIC uses DMA to read data in the user-specified buffer and transmit it as a self-contained message across the network. The receiving NIC then uses DMA to place the data into the user-specified buffer. There is no intermediary copying and all of these actions occur without the involvement of the CPUs, which has an added benefit of lower CPU utilization.
For the NIC to actually access the data through DMA, the user's page must be in memory. In VIA, the user must "pin-down" its buffers before transmission, so as to prevent the OS from swapping the page out to the disk. This action—one of the few that involve the kernel—ties the page to physical memory. To ensure that only the process that owns the registered memory may access it, the VIA NICs require permission keys known as "protection tags" during communication.
Line 19 ⟶ 20:
==External links==
*[http://www.usenix.org/publications/library/proceedings/als00/2000papers/papers/full_papers/rangarajan/rangarajan_html/node3.html Usenix Notes On VIA]
*[https://makonetworks.com/markets/distributed-enterprises/ Distributed Enterprise Networks]
*[https://noggin.intel.com/intelpress/categories/books/virtual-interface-architecture
[[Category:Supercomputing]]
[[Category:Computer networks]]▼
{{Compu-network-stub}}
▲[[Category:Computer networks engineering]]
| |||