Re: point-to-point conferencing

Ian Carr-de Avelon (avelon@phys.uva.nl)
Sat, 29 Jul 1995 20:38:23 +0200


At 08:56 28-07-95 PDT, Carl Shannon wrote:
>I thought the IP number directed data to the server. How is it that the
server
>directs it to me, rather than some other subscriber?
>
>Thanks,
>
>Carl
>
Each computer on the Internet has its own unique IP number. Any computer can
send packets of data to any other computer because every computer that the
data needs to pass through has a simple way of knowing what to do with any
packets it receives, from the IP number in the packet.
eg. if software on my PC, pc-ia184.phys.uva.nl (145.18.222.184)
asks the Winsock to send a packet to another IP. If the IP is not my
computer's own number, it knows to send it to our section's gateway:
volta.phys.uva.nl (145.18.222.1). If the IP is within the numbers of the
University of Amsterdam, uva, volta can pass it through the University's
net. Otherwise it will be sent to the NL-net to handle. etc.
The Internet "knows" to pass all packets with IP numbers which correspond to
your Internet provider, including yours, to their gateway. Once it has the
packet the gateway knows that it is not to be passed to software running on
the gateway (say, a reflector) because the IP number is not its own number.
It looks which modem connects it to that IP number and sends it off.
Yours
Ian
*************************************************
* Ian Carr-de Avelon avelon@phys.uva.nl *
* http://pc-ia184.phys.uva.nl/avelon.htm *
* *
* dept. of Physics Education *
* University of Amsterdam *
* Netherlands *
*************************************************