Virtual Networks
| Depends on | Virtualisation |
|---|
A traditional computer network – if there was such a thing – comprised some form of interconnection hardware (wires) with some software to control these. Sometimes the software imposed some security, e.g. it restricted what could communicate with what.
In one sense, once the network extends beyond your local interconnection, it may be virtualised, so remote machines still appear as if they were locally connected: the need to send messages via satellites (or whatever) can be hidden from the user.
Alternatively a virtual network may be confined entirely within a single computer, which is itself running multiple virtual computers: this could be, for example, a means of running both Windows and Linux applications together if you only have a single physical machine. On a slightly smaller scale this might be interconnecting containers within a machine.
Another approach to virtualisation is typified by the Virtual Private Network (VPN) which builds what looks to users like a separate network within a large network (such as the Internet). This allows existing infrastructure to be exploited whilst maintaining the privacy of a local private network.
Of course, because the data is transported across a public medium, various security precautions are necessary, such as:
- Authentication: are correspondents really who they say they are?
- Encryption: messages will, in principle, be visible to third parties; is there meaning kept hidden?
- Integrity: are messages being tampered with?
However, other than the principle of virtualisation this is moving more into networks than operating systems, so that’s enough for here.
