The network access layer is also called the host-to-network layer. The network access layer is the layer that is concerned with all of the issues that an IP packet requires to actually make a physical link to the network media. It includes the LAN and WAN technology details, and all the details contained in the OSI physical and data-link layers.

Software applications and drivers or modem cards often handle the network access layer. The software applications and drivers are the ones designed for individual pieces of hardware, such as Ethernet or Token-Ring NICs, and ISDN. There are a wide variety of protocols defined by other standards that reside at the network access layer, which lead to confusion for users. The Internet and Transport protocols are more quickly recognized. The application protocols of SMTP, HTTP, and FTP, as being part of TCP/IP are also quickly recognized.

Network access layer functions include mapping IP addresses to physical hardware addresses and encapsulation of IP packets into frames. Based upon the hardware type and the network interface, the network access layer will define the connection with the physical network media.

A good example of network access layer configuration would be to set up a Windows system using a third party NIC. Depending on the version of Windows, the NIC would automatically be detected by the operating system and then the proper drivers would be installed. If this were an older version of Windows, the user would have to specify the network card driver. The card manufacturer supplies these drivers on disks or CD-ROMs.

Interactive Media Activity Drag and Drop: The Network Access Layer When the user has completed this activity, the student will be able to identify the protocols used in the Network Access Layer.

   

Web Links Network Access Layer http://www.pku.edu.cn/academic/research/ computer-center/tc/html/TC0200.html