Network Protocols: -
Protocol is a set of rules that determine how the date is transmitted over the network. It is a
communication standard followed by computers in a network to communicate with each other. Protocol exists as several levels such as hardware device level, software level and application program level. For example, in the OSI model different protocols are used at each layer for communication between the computers connected in a network.
Different types of network protocols include NetBIOS/NetBEUI, TCP/IP, IPX/SPX, UDP, ICMP/IGMP, ARP/RARP AND HDLC/SDLC.
In that few explanations about the protocols
NetBIOS/NetBEUI: - Network Basic Input/Output System is an application programming interface. Applications located on different computers use NetBIOS to communicate with each other over a Loval Area Network. It was developed by International business Machines Corporation (IBM) for their network. Later It was adopted by Microsoft. It is widely used in Ethernet, Token ring and Windows NT networks. It supports connection oriented communication such as Transmission Control Protocol (TCP), and connectionless communication such as User Datagram Protocol (UDP). Net BIOS is a set of services that is provided to the applications, whereas NetBEUI is used to implement these services.
The session service functions offered by NetBIOS are;
Call: Initiates a session with a machine with a specific NetBIOS name.
Listen: Waits to open a session with a known or unknown caller.
Hang up: Closes a session.
Send: Sends date to the computer on the other side of the session.
Send No Ack: same as send, but doesn’t require an acknowledgement after sending data.
Receive: Receives data from the computer on the other side of the session.
Session Status: Gets information on the requested sessions.
NetBEUI: -
NetBIOS Extended User Interface (NetBEUI) is an enhanced version of the NetBIOS protocol used by LAN manager, LAN server, Windows for workgroups, Windows 95 and Windows NT. It is essentials that the interface of NetBEUI is adapted to other protocols such as Internetwork Packet Exchange or TCP/IP as it does not support routing of messages to other networks. You can install both NetBEUI and TCP/IP in computer and use NetBEUI for communication within the LAN and TCP/IP for communication outside the LAN. NetBEUI provides name service, datagram service and session service. It uses unacknowledged connectionless mode to provide name service and datagram service. Virtual circuit approach is used to provide session service. Virtual circuit approach involves a connection between communicating devices that appear as a direct connection but in reality it is an indirect path.
TCP/IP: -
Transmission control protocol/ Internet Protocol is the basic communication protocol used by Internet. It is also used for communication in a private network such as
internet or Extranet. TCP/IP is a two layer protocol. The higher Layer TCP protocol divides the message into smaller packets called segments and transmits those segments over the network. These packets are then received by the TCP layer of other machine. This layer reassembles the segments into the original message. TCP consumes more bandwidth, to provide error recovery. It also performs various functions such as Multiplexing, Error recovery, Flow control, Connection establishment and termination, End to end sequenced data transfer and Segmentation. TCP performs its functions the same way regardless of whether two computers are on the same network or on different network separated by internet. The lower layer IP protocol manages the addressing part of the packets so that they will reach the correct destination. Each router used in the network checks these addresses to determine where to toward the packets. Even if the packets of same message follow different routes to reach the destination, they will be assembled into original message at the destination.
TCP/IP Suite: -
Prior to the OSI Model, the TCP/IP protocol suite was developed and hence the layers in the TCP/IP protocol suite differ from the layers of the OSI model. Physical, Data Link, Network, Transport and Application are the five layers of TCP/IP protocol suite. The first four layers of the protocol suite provide physical standards, addressing, internetworking and transport functions. These functions match with the first four layers of the OSI model. The Application layer includes the three topmost layers of the OSI model.