Well, i'm studying to a test, based on the following layers: link, internet, transport and application (Architecture TCP-IP) i would like to know which layer or layers "routers" work and why it can't work in another layers.
Not quite sure what you mean by, "why can't it work" in other layers.– HALMay 29, 2014 at 21:03
I would like to know why router can't work in link or application layer.– Mr.LanhellasMay 29, 2014 at 21:11
Generally speaking, routers utilize the IP protocol (i.e. IP addresses) to make decisions while directing traffic and do not care about the transport protocol. The IP protocol would map to the internet layer.
The TCP or UDP protocols would operate at the transport layer. Typically a device that would direct traffic based on transport layer protocols (or application layer) would include proxies, load balancers, or shaping devices depending on its exact function.
Devices that operate at the link layer (most often Ethernet today) would include switches or bridges.
Routers operate on the Internet layer of the TCP-IP model. The Internet layer is synonymous with the Network layer of the OSI model.