Talk:Open Systems Interconnection Reference Model

Article Checklist for "Open Systems Interconnection Reference Model"

Workgroup category or categories	Computers Workgroup [Categories OK]
Article status	Developing article: beyond a stub, but incomplete
Underlinked article?	Yes
Basic cleanup done?	Yes
Checklist last edited by	Greg Woodhouse 16:40, 9 April 2007 (CDT)

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Meaning of switch

I changed the link back from electronic switch, because in the context of computer networks, "switch" has a different meaning. An electronic switch could be an electronic component like a transistor or a latch, but a network switch is a computing device, albeit of a special type. Both layer 2 devices (such as bridges) and layer 3 devices (such as routers) have been called switches. Radia Perlman (the inventor of the spanning tree bridge) somewhat sarcastically said that switch is a word meaning "fast" (see her book, Interconnections for a detailed, and readable, treatment). In fact, the term switch really has less to do with how the device works, but with how it is used. ATM switches are technically layer 3 devices, but are used in much the same way as layer 2 switches. "Fast Ethernet" (100baseT and 1000baseT) is switched, even though Ethernet/802.3 is a layer 2 protocol. (Remember that 10baseT does not require switching.) Greg Woodhouse 11:36, 12 May 2007 (CDT)

Greg, I have modified the "switch" link on this article to say "network switch" (which I think is the same as a router anyway). The plain old "switch" link is redirected to the Electronic switch. There are many links to "switch" from various computer articles that really do need to go to Electronic switch. So we need a disambiguation page, but I don't know how to make one.Pat Palmer 11:53, 12 May 2007 (CDT)

Not necessarily. If you have to physical networks connected by a switch and then use traceroute (tracert on Windows) to path from a host on one segment to one on the other, you won't see the switch. However, if they're connected by a router, you will see the router. On the other hands, there are contexts where switches and routers are pretty much the same thing. Part of the problem, and something that really needs to be addressed in this article, is that the OSI model is not always a perfect fit for network technology, so thee can be a certain degree of arbitrariness in the assignment of network devices to OSI layers. Greg Woodhouse 12:03, 12 May 2007 (CDT)