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How does it work?

By mginnis ·
Hi everyone!

My question to you is - How does an ISP work?

I need to know the mechanics behind an ISP.

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by dmiles In reply to How does it work?

Some of the software you use on the Internet has to be configured to work with the server operated by the ISP that you use. The best source of information for your connection is your ISP, who can provide you with the necessary details to enable you to connect to their service.

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by mginnis In reply to How does it work?

NO, what I need to know is what servers do you need to setup your own ISP

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by mginnis In reply to

I sort of need a schematic drawing of all components

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by laird.Beamesderfer In reply to How does it work?

The servers required all depends on the services that you want to provide. The major services are Newsgroups, E-Mail, Web Hosting, etc...

How an ISP works is generically like so:
The ISP has a dedicated pipe to the internet with a reserved number of IP addresses. You then provide equipment for your end-users to connect to you (via dial-in/wireless/etc.).

Check out this link
to help understand everything associated with an ISP.

You must understand that your question is very broad, as an ISP can be set up with all different types of equipment.

Hope this helps you.

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by TheChas In reply to How does it work?

An ISP has the following:

A high speed connection to the "backbone" of the internet. At least a T1 line.

A mail server.

A modem bank connected to the phone lines that users dial in on.

A web page server if the ISP hosts web pages.

A router to interconnect the mail and web servers to the modem bank and the T1 line.

Backup power.

Data backups for the mail and web servers.


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by uffe.sommerlund In reply to How does it work?

An ISP works like this

he is connected via some Frame Relay to other Networks. The Providers main job is to ROUTE you through the internet.

Setup ISP

One with many interfaces (subinterfaces) or more Routers for routing costumers. An interface in a router holds an static IP address for each interface - subinterface for each line the ISP then link them to the bigger router on some other ISP's this could seem like a lot of interface's and that's why a lot of them manufactors of the routers created something called a subinterface. Subinterfaces is a virtual interface underlying the real interfaces and they are also intitle to hold an IP Address. in the old days of the interface there where very large routers out there and many of them to be able to contain all these interfaces and the ROUTING tables where enourmous and the routing time slow. Therefore the big Router vendors created ROUTE summarization
this means that you take all your IP addresses within an address range example IP address + + and find the equalized subnet for all them addresses and route them all through interface eth0 this will save the time in the routing engine since the packet are (forwarded faster) the normal way a router works without route summarization everytime a router receive a packet it looks in the routing table to see where to send the packet, but when doing the summarization then it will forward the packets much faster.

Fallover: the ISP has of course more than one router and they could set them up with different scenarios (Hot Standby) or the better and more effecient use is Load Balancing where the ISP can balance the traffic comming from different IP address ranges, once a session is started from remote host (router) that session goes roughly the whole session through the same gateway. (router).

Users Line: The comment thing for an ISP is to offer a range of getting services (Broadband XDSL

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by uffe.sommerlund In reply to

technology I have put in the X since there are different forms of DSL) SDSL is symmetric meaning upload and download is the same speed. ADSL asymmetric the upload is different from the the download speed. The provider has different method of doing XDSL technologies there is the way with something named the DSLAM this is with a Cisco Backbone using ATM technology. It works like this all the packets that u send gets a Name tag (from a edge router) when it enters the DSLAM backbone it is then forwarded to the next switch which gives it a new Name Tag (label) the packet then traverses throgh that whole Switching Backbone looking at the label which holds the end destination and come out at the end of the line and gets further router to the final destination. The benefit of this Name Tag thing is that Frame Tagging is much faster than using a router since a switch could be configured to only look at the frame of the packet and forwarding as soon as it knows the destination this is known as Multi-Protocol Label Switching (MPLS) technology.

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by uffe.sommerlund In reply to

When providing users with Modem then the ISP will need a router with different kind of interfaces Cisco provides Routers who is capable of doing DSL, Modem support or ISDN access it is only a matter of configuartion. It could also be done with a Universal Broadband router in which you could put many modem cards or Connections in.

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by uffe.sommerlund In reply to

in the end then of course you'll need the different services to offer to your costumers:
Email server access (email account + webaccess)
DNS servers.
Backup + UPS system for redundancy
Proxy servers for Modem users.
Virus protection.
Traffic filtering (firewall)
VOIP ??? then you'll need to calculate the broadband for this issue when compressed each user use 53KB pr. sec.
some E1 + maybe Frame Relay

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by uffe.sommerlund In reply to

to Punez

it is not a matter of running DHCP from your ISP the ISP just hand out his own subnet (Private IP scope)

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