COMPUTER NETWORK

Novel NetWare, Routers, Bridges and Gateways

Novel NetWare

NetWare is another brand of operating system designed for networks or simply a local area network (LAN) operating system. And, this OS is a product of the popular IT-centered company Novell, Inc. This is a kind of software that may be used in various types of local area networks such as Ethernets and IBM token-ring networks. A dependable interface may be expected by both users as well as programmers when using the NetWare. It does not rely much on the specific hardware, which is utilized in sending out messages.
Novell’s NetWare was primarily dedicated for the installation
In both large and small LANs. But then Novel, Inc. decided to upgrade their product and they added some other features into the network OS NetWare. The company’s chief purpose for improving the capacity of their product is to make it applicable for larger and diverse networks like the Internet.
This was first utilized in cooperative multitasking in order to operate other services found on a personal computer. And, the network protocols of this operating system were all patterned on the more standard stack Xerox Network Systems.
NetWare is a succession of the Novell’s Open Enterprise Server (OES) during the year 2005. And, the most recent edition of Novell’s NetWare is the v6.5 Support Pack 8 and this product is similar to the OES 2 SP1 NetWare Kernel.
NetWare became very well-known that it surpassed all the other network operating systems (NOSs) present in the market during the middle of the year 1980s and 1990s. It was proven at that period of time that NetWare truly had an exceptionally high level of performance as compared to the other NOS being sold during those past years. During the early existence of the Novell NetWare, its number one opponent was the Windows NT operating system, which is a product from the large technology company Microsoft Corporation.

Routers

A router is a device like a switch that routes data packets based on their IP addresses. Router is mainly a Network Layer device. Routers normally connect LANs and WANs together and have a dynamically updating routing table based on which they make decisions on routing the data packets. Router divide broadcast domains of hosts connected through it.

Basically routers are used:

To connect different network segments.
To connect different network protocols such as IP and IPX.
To connect several smaller networks into a large network (known as the Internetwork)
To break a large network into smaller networks (Known as the Subnets. Usually created to improve the performance or manageability.)
To connect two different media types such as UTP and Fiber optical.
To connect two different network architectures such as Token Ring and Ethernet.
To connect LAN network with Telco company’ office (Known as the DTE device).
To access DSL services (known as the DSL Router).

Bridges

A bridge operates at data link layer. A bridge is a repeater, with add on the functionality of filtering content by reading the MAC addresses of source and destination. It is also used for interconnecting two LANs working on the same protocol. It has a single input and single output port, thus making it a 2 port device.
Types of Bridges

Transparent Bridges:- These are the bridge in which the stations are completely unaware of the
bridge’s existence i.e. whether or not a bridge is added or deleted from the network, reconfiguration of
the stations is unnecessary. These bridges make use of two processes i.e. bridge forwarding and bridge learning.
Source Routing Bridges:- In these bridges, routing operation is performed by source station and the frame specifies which route to follow. The hot can discover frame by sending a special frame called discovery frame, which spreads through the entire network using all possible paths to destination.

functions of bridge

Gateways

A gateway, as the name suggests, is a passage to connect two networks together that may work upon different networking models. They basically work as the messenger agents that take data from one system, interpret it, and transfer it to another system. Gateways are also called protocol converters and can operate at any network layer. Gateways are generally more complex than switch or router.
Gateway is used to forward the packets which are generated from the local host or network and but intended for the remote network. If a data packet does not find its destination address in the local network then it takes the help of the gateway device to find the destination address in the remote network. A gateway device knows the path of the remote destination address. If require, it also changes the encapsulation of the packet so it can travel through the other networks to get its destination address.

gateway

Examples of the Gateway

Email Gateway: - Translates SMTP e-mail in standard X.400 format before forwarding.
GSNW Gateway: - Allows Windows clients to access resources from the NetWare server.
PAD Gateway: - Provides connectivity between LAN network and X.25 network.