3Com AccessBuilder 500 User Manual - page 109

C-7

Network layer

 The third layer of the OSI reference model. This layer is 

responsible for controlling message traffic.

NFS

 A network file system developed by Sun Microsystems for shared 

files over a UNIX platform.

Node

 An alternative name for a computer or device (such as a printer 

or modem) that is connected to a network.

NOS 

  Network operating system.

OSI

 Open Systems Interconnection, a body of standards set by the 

International Standards Organization to define the activities that must 

occur when computers communicate. There are seven layers, and each 

contains a specific set of rules to follow at that point in the 

communication.

PAP

 Password Authentication Protocol. Part of the PPP protocol to 

ensure authentication of the connection between two devices.

Peer-to-peer network

 A network which contains workstations which 

are able to act as both client and client servers.

Piggyback

 A way of transmitting routing information over ISDN lines 

by adding it to valid data frames. This avoids ISDN calls being 

generated solely for passing routing information.

Physical layer

 The first layer of the OSI network layer model. This layer 

manages the transfer of individual bits of data over wires, or whatever 

medium, that is used to connect workstations and peripherals.

Polling

 A method of controlling terminals on a multi-point network 

where each device is interrogated, in turn, to determine if the device is 

ready to receive or transmit data.

PPP

 Point-to-Point Protocol. The de facto standard protocol for 

routing between devices made by different manufacturers.