• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

important of computer networking ?

Status
Not open for further replies.

Parth86

Member
Hello everyone
Networking is process for connected two or more computers for sharing information and data.
example : hotel computer networks that enable travelers to make reservations from any wherein the country.
could you someone tell me why we need to set up network while we do all work on internet. why we need switch or hub in network. if i want want to send email, I don't see that my device is attached to any switch or hub ?
 

ronsimpson

Well-Known Member
Most Helpful Member
Computer networks are much like phone networks.
In my country, years ago, there were women in every town that "switched/routed/" the phone lines. They would connect your wire to your friend's wire so you can talk. Then when you are done they disconnected the wire. (all wires come to a center point) Now computers do this job.

I don't see that my device is attached to any switch or hub ?
On the phone you don't see the switch but it is there. Probably many switches are used when you call home.
why we need switch or hub in network.
With out a "hub/switch/router" there must be a wire from your house to every house in the world. (too many wires)
With a hub you only need a wire to the first hub. Then that hub only needs one wire to the next hub. (much less wires)
 

Reloadron

Well-Known Member
Most Helpful Member
What is a Computer Network? - Types & Definition
A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is connection to the Internet. Other shared resources can include a printer or a file server. The Internet itself can be considered as a computer network.
Before I retired I shared several networks through my work. Daily I networked with thousands of computers globally. This allowed us collaboration and the sharing of resources across the network. Retired now I share a home network with my wife's computer and our home server network. We can share in a few printers, scanners and other hardware across the home network. We also share in an email client away from home network as well as off site storage. Are networks necessary? No, not really but they can be very beneficial in many situations, especially when sharing resources.


Ron
 

Parth86

Member
What is a Computer Network? - Types & Definition


Before I retired I shared several networks through my work. Daily I networked with thousands of computers globally. This allowed us collaboration and the sharing of resources across the network. Retired now I share a home network with my wife's computer and our home server network. We can share in a few printers, scanners and other hardware across the home network. We also share in an email client away from home network as well as off site storage. Are networks necessary? No, not really but they can be very beneficial in many situations, especially when sharing resources.


Ron
thank you very much for helping me. I have doubt suppose I have three computers A, B and C and I have one printer. I just want to share printer for three computers and also want share file together. what should I have to use hub or switch ?
I think switch but I don't know exact reason when does we use switch or hub in network ?
 

ronsimpson

Well-Known Member
Most Helpful Member
Because the phone system and internet networks are about the same and they grew up the same way, I have a story.

When I was young; it costs too much money to run phone wire(s) in the rural farm country. There are wires all over town. In the country about 10 houses are connected together on one wire. To call your neighbor you pick up the phone and listen. If some one is talking then you should hang up and wait. If you hear a dial tone then you can dial. These little "party lines" were built on a two digit system. "15" is for house 5, "25" is for house 15. "0" is for the operator. When you dial, a small mechanical computer listened for the numbers. Then the computer would put "ring current" on the line and every ones phones rang. There was different types of rings, one for each house. (long ring+short ring)=house 1, (short ring+long ring)=house 2, (long + long)=house 3, etc If you dialed 99 then there was an emergency (fire), the ring was very long with no breaks, every one picked up. If you dialed 0 then your "network" connected to town.

To talk long distance; Dial 0, connect to town, tell the operator the name of the town, then you are talking to the operator in that town. Each town had a wire to all the close towns. (no very long wires) If you wanted to talk to a town 100 miles away you would have to talk to the operators in each town from here to there. You could really only go about 5 towns away because the signal got too week.

Some small house networks are much like the party line. The wire has all traffic on it. A packet of data = ("I am computer 1 and this data is for computer 2...[data]...end") Computer 5 will see this but not respond.
----------------------------
In town we had a 4 digit system. 4xxxx connected you to house xxxx. 1 connected you to an long distance operator, 0 connected you to a local operator (in town). 9 connected you to an emergency operator. There was a switch board like the one in post #2. (run by a mechanical computer) If phone 105 called phone 206 then those two wires are connected together. At the same time phone 300 could call phone 045 and those wires are connected together. 100 people could talk at the same time. There are no sharing of wires.

Some computer networks are like this. Where several computer can talk at the same time.
---------------------------
In all cases each small network is like a family. Then there is a connection to the next network, next network, next network all the way around the world. My network has 3 routers and 16 computers. There is only one connection to the internet. In town there probably is a network that has a dish pointing at the sky and 10 fiber connections to other networks. (no computers)
 

ronsimpson

Well-Known Member
Most Helpful Member
switch or hub in network
Hub is like a "party line" in post #5. All computers see all the data. If is good for home networks and small business.
Switch is where the data is looked at by the switch and sent only to the right computer. Is good where there is large amounts of data.
Router is used to connect your network to another network. (your house to your provider) A router often includes a hub or switch so you have a place to connect several computers.
 

Reloadron

Well-Known Member
Most Helpful Member
I have doubt suppose I have three computers A, B and C and I have one printer. I just want to share printer for three computers and also want share file together. what should I have to use hub or switch ?
I think switch but I don't know exact reason when does we use switch or hub in network ?
What’s the difference between a hub, a switch, and a router?

In a word, intelligence.

Hubs, switches, and routers are all devices that let you connect one or more computers to other computers, networked devices, or even other networks. Each has two or more connectors called ports into which you plug in the cables to make the connection. Varying degrees of magic happen inside the device and therein lies the difference. I often see the terms misused, so let’s clarify what each one really means.
We can Network as few as two computers using a simple crossover cable. When we have three, four or even five computers we can form a network using a router (intelligence) as a peer to peer group of computers. When we begin to exceed five computers and depending on the needs we can allow a server where each computer works through the server. Really a matter of our specific needs. My wife and I share two printers and a scanner but also each of our tablets and smart phones can print across and use our home network. So when forming a network you try to look at your current needs as well as possible future needs and build the network around needs. The above posted link does a good job of breaking down switches, hubs and routers with the latter being more intelligent.

Ron
 

ronsimpson

Well-Known Member
Most Helpful Member
Vead,
Because you have a small network, you can use a old (used) switch. There is no reason to spend big money. There are many people that must have the best equipment, and they send last year's equipment to the trash. I would look for a wireless switch. Even if you don't have a need for wireless. My phone uses wireless and it is set to use the house network when it can to reduce the data over the phone network.
For years I used a older version of this.

With out wireless I used this:
 

Reloadron

Well-Known Member
Most Helpful Member
Vead, if you were local I would send you a router or switch. I have a pile of old units laying around including a few Linksys wireless routers. We use cable modem and the new box does everything including the house phone.

Ron
 

Parth86

Member
Vead, if you were local I would send you a router or switch. I have a pile of old units laying around including a few Linksys wireless routers. We use cable modem and the new box does everything including the house phone.

Ron
Mr. Ron Thank you very much for your explanation, your efforts. I live in india . I always like to do some real work . I am planing to purchase switch , hub . I have downloaded some books. do you have some idea which links or books are best for learning networking
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Ethernet has two basic protocals. One being TCP/IP and the other being UDP.

TCP/IP is basically a guaranteed delivery. The receiver re-assembles the packets n the correct order even if they arrive out of order. There is error checking in this protocol.

That protocal isn't good for video and audio. In this protocol, packets might not make it. QOS or Quality Of Service was introduced to prioritize traffic.

Hubs just mix everything together. Everything connected sees all the traffic.

Switches on the othe rhand if you had 3 computers, A, B and C and one printer if A was printing B and C would not see that traffic.

Businesses will use a managed switch. They are classified as L1, L2 and L3 or Layer 1, 2 and 3. The Levels, basically define what they can do.

as the Internet matured, the role of the router, switch, hub, bridge etc has morphed a bit, Switches can perform router functions and VLAN's or Virtual LANS were created.

So, an IP phone would have a separate VLAN associated with that network. Traffic destined for a printer wouldn;t collide with voice traffic at all.

There is something called multicasting and unicasting. If you were "televising" (delivering a live performace via the Internet), it makes sense to have one source and many destinations. Unicasting, sets up a link between two devices,

So, there is a lot of stuff going on,

A simple bridge would be when traffic say travels via fiber.

In a home with a DSL modem, router, switch and Wireless. They can all be combined together, The wireless in generally used in Bridge mode, but Access point devices have a few different modes taht it can use. Bridge or Access Point mode. They can even set up ethernet to wireless to ethernet bridge. e.g. A printer could pass traffic via Ethernet-wireless-Ethernet to the printer and that wireless network is separate.

The router portion gets you out of subnet. Home routers use NAT to make all of your computers effectively routeable to the Internet if you allow. The public I address has services or PORTS associated with it. HTTP is port 80. If a request came in for port 80 of the public IP address, the router says, that goes to my http server on addresss 10.0.1.200.

DSL in bridge mode is quite unique, When traffic leaves the WAN port of the router, it travels via a DSL bridge to the DSLAM (A DSL telco thing). From there is travels using an ATM protocol ( a telco thing) and eventually to a router via ethernet. So, when you ping the IP address of your public IP from inside your netowork, the packet travels through the telco lines and ATM until the router at the end point responds. For me that router is located about 40 miles from me.

A ping packet sent from outside the network, wouldn't even see the telephone line or the ATM network.

So, there's lots of stuff going on,

What makes a lot of this possible is that every interface gets a unique MAC address. Unique makes it easier. The only thing that matters is that the MAC address is unique in the routeable segment. Thus you can CLONE MAC addresses of cable modems. With cable, everyone is on the same wire, so the cable company uses the MAC address to know it's you. If you change your cable modem, you either have to have the cable company re-authenticate you or just make the MAC address the same as your old cable modem.

DSL doesn't need that, since it's a different physical wire.

You create routeable segments with an IP address. some are public (visible to the Internet) and some are private (non-routeable to the Internet, just the local LAN).
 

Reloadron

Well-Known Member
Most Helpful Member
Mr. Ron Thank you very much for your explanation, your efforts. I live in india . I always like to do some real work . I am planing to purchase switch , hub . I have downloaded some books. do you have some idea which links or books are best for learning networking
There were several books published by Microsoft Press about Networking Inside Out but I believe they focused on older operating systems like Windows XP. Amazon seems to offer up a good selection of
Networking & Cloud Computing books which may be of some interest.

Ron
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top