We connect to ISP...ISP connects to what?
Discussion
I have always wondered we connect to the ISP, I understand that bit but what does the ISP connect or dial into? Is there a main access point that they all use? or do they connect to several other ISP's at the same time? I mean is AOL conected directly to Tiscali in some sort of star network? 
Is there some huge fat cable just taking all the data between them...OH and how does it connect to the rest of the world? is there multiple connections overseas.
I read somewhere that the idea of the internet was to stop any connection if it gets bombed.
And another thing where is the name www.?????.com to IP held? is it all on one humungus computer?
May seem obvious to you clever lot but left me utterly lost.
Is there some huge fat cable just taking all the data between them...OH and how does it connect to the rest of the world? is there multiple connections overseas.
I read somewhere that the idea of the internet was to stop any connection if it gets bombed.
And another thing where is the name www.?????.com to IP held? is it all on one humungus computer?
May seem obvious to you clever lot but left me utterly lost.
Go read your history, chaps. The Internet (inter being latin for "between" ) is a network of networks. It originally connected various academic and military networks in a kind of web-like connection. It has since grown, and various ISPs do indeed connect together, but not directly to each other but through a backbone (so there is a bit of a hierarchy).
So it isn't quite as simple as ISPs connecting to other ISPs
(Edited because a " followed by a ')' still gives a winky smiley, unfortunately)
>> Edited by JonRB on Thursday 17th November 08:59
So it isn't quite as simple as ISPs connecting to other ISPs
(Edited because a " followed by a ')' still gives a winky smiley, unfortunately)
>> Edited by JonRB on Thursday 17th November 08:59
scared but happy said:
And another thing where is the name www.?????.com to IP held? is it all on one humungus computer?
A distributed database called Domain Name System (DNS) google for that for more info than you could possibly want.
search terms;-
DNS
rootservers
bind
Oh! Just remebered: www.linx.net/
London INtetnet eXchange, peak traffic for the last day or so: 103Gbps
What's the betting there's one or two small black goverment boxes plugged in at strategic points?
>> Edited by aldi on Thursday 17th November 18:00
London INtetnet eXchange, peak traffic for the last day or so: 103Gbps
What's the betting there's one or two small black goverment boxes plugged in at strategic points?
>> Edited by aldi on Thursday 17th November 18:00
andy mac said:
I've always wondered that. Why do we have to have an ISP... Why can't we just connect to where the ISP's then connect us to?
You can.
Bandwidth is no different from anything that needs billing, distribution and value adding in order to make it acceptable to the end user.
If you've got loads of money, or are a business, and know what you're doing, ie don;t need email addresses, web space, support, just bandwidth and some IP addreses, a leased line from BT, NTL, UUnet et al will be as close as you get.
scared but happy said:
I understand that bit but what does the ISP connect or dial into?
the basic sequence -
pc connects thru...
telephone exchange
ISP login server
isp a/c session
dns root server
dns domain server
remote isp domain server
dns domain server confirmation
isp server space
phone exhange
home pc modem etc
+
signal booster/s depending on distance vector
+
various routers an hubs depending on path direction an distance
+
sw an hw firewalls
scared but happy said:
I have always wondered we connect to the ISP, I understand that bit but what does the ISP connect or dial into? Is there a main access point that they all use? or do they connect to several other ISP's at the same time? I mean is AOL conected directly to Tiscali in some sort of star network?
Is there some huge fat cable just taking all the data between them...OH and how does it connect to the rest of the world? is there multiple connections overseas.
I read somewhere that the idea of the internet was to stop any connection if it gets bombed.
And another thing where is the name www.?????.com to IP held? is it all on one humungus computer?
May seem obvious to you clever lot but left me utterly lost.
The internet (as opposed the the WWW) is a physical thing, a network of networks all speaking to each other at meeting (or peering) points. the largest of these are Internet Exchanges like the London Internet Exchange LINX.
Every ISP has their own network defined by it's AS Number which is used to find it via a Routing protocol called BGP, every network with an AS number must run BGP routers, these routers hold the address and path information to allow them to get to any other BGP network on the planet via the shortest path - or indeed via an alternative if the shortest is broken. When you connect to the ISP via dialup or broadband your computer is given an IP address within the ISP's network and you are then able to use their gateways to the internet of which they have several - but remember an ISP connection is only a connection to their network, not to the Internet as a whole so they may well sell you a connection to them which is faster than the connections they have available to the Internet for al their clients. ISPs connect to the rest of the internet via peers or connections direct to other network operators. Some of these are called private peers over which they share traffic because the volumes of data are broadly similar in both directions or because the other party is a content originator and it is in their adavantage to do so - so BT will peer with the BBC and ebay so that traffic to those huge sites goes direct between the bbc and BT and not over the internet (which in this case means other networks). ISPs also have Public peers to the largest Carriers (or Tier 1 Carriers) companies like Level3, MCI, ATT, Global Crossing and Telia who are large enough to own the fibre in the ground and most importantly under the sea which carries the traffic of smaller networks. These companies don't buy connectivity because they are its originators and they have the largest number of peers making their network a fast path to more other networks than a smaller provider can deliver. The public peers are paid for with the ISP paying mer Mbps for the traffic they pass over the connection. The cost per Mbps for this traffic is likely to be more then the cost of a similar sized ADSL connection.
why can't you just do what they do? well it is a combinaton of cost - a consumer ISP network will set you back several milion if you want to do standard broadband and rather more for ADSL2 - and capacity. There are only 65000 AS numbers and a shortage of IP addresses until IPV6 gets underway so the process of getting an AS means you have to be able to demonstrate the need for at least 1048 IP addresses (which means 1048 computers or devices) and you have to buy the licence which costs more than about 10 years broadband per year.
It is also worth understanding this more closely in the light of all the comapnies now offering ADSL2 with speeds of 24Mbps. The reality is they are likely to be contending this connection at the exchange, contending it again at a core exchange and again at their gateway to the internet. They will be cacheing hige ammounts of the traffic at each site and so you will not be getting 24Mbps connection to the Internet, just to their network. The largest connection available between networks is currently 10Gbps there are I think three connections like this in the UK one of which is on the university network Janet. There are only 3 carriers who can offer this outside the USA so before you sign up to a super fast broadband provider remember that the ammount of bandwidth they can buy has not gone up 24 fold in line with their offerings...
hope this is clear, however it may make things worse !!
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