This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and data networks by bertsekas and gallager pdf download layer.
This layer may be implemented by a PHY chip. The physical layer consists of the electronic circuit transmission technologies of a network.
It is a fundamental layer underlying the higher level functions in a network. Due to the plethora of available hardware technologies with widely varying characteristics, this is perhaps the most complex layer in the OSI architecture.