dial-up internet

UNIX for Advanced & Expert Users
1

Hi,

I want to know working of dial-up internet on the PC.

Please tell me how internet connection and ip address assigning happened.

I know all this procedure in the broadband internet. But I confused for the

'dial-up' and 'internet in mobile'.

I am eagarly wait for yours reply.............

Regards,
Jagdish

2

Technically, the only difference between dial-up and broadband is

(a) broadband is always on, typically machine use DHCP to allocate an IP address

(b) dialup requires machine to initiate a modem connnection to run either PPP or SLIP protocol over the serial link.

3

Hi,

That means in dial-up connection, DHCP is not used for assigning IP address.

Is it possible that IP address is able to assigned to modem?

Regards,
Jagdish

4

A modem connection can or cannot get its IP address via DHCP, the two things do NOT have to do anything with each other at all.

For DHCP to work you have to have a working IP-capable interface. Such an interface could be a NIC (connected, correct drivers installed, etc.) but also a PPP-line, a SLIP-line or several other things. PPP, like SLIP and several others, are layer-2-protocols and just "create" (so to say) a line able to transmit IP traffic.

So what you do in fact is: using some Layer-2-protocol you call a network interface able to transmit/receive IP traffic into existence. This interface may - in terms of IP configuration - be configured via DHCP like any other interface called into existence.

bakunin

5

Hi Bekunin and Porter,

First of all thanks for the reply to thread......

 That means you mean to say.... we can able to assign IP address

  and MAC address......same as we do for LAN card........

 Tell me I am write or wrong.......

In dial-up ISP,  they varifying our 'username' and 'password' and

after verify it...DHCP server assigns IP address to the 'modem'..

and finally user access the internet......please verify it....

Regards,
Jagdish

6

Yes, more or less:

It is more like that: your modem opens a ppp-line by calling your ISP and creates a layer-2-interface, just like your NIC would do. Basically for any software working on top of layer 2 (that includes DHCP and any other IP-based protocol) a network card and your modem "look the same".

Not your "modem is assigned an IP-address", but the layer-2-interface created by the modem opening a PPP-line is. I suggest you make yourself familiar with the 7-layers OSI model ( OSI model - Wikipedia, the free encyclopedia ) to fully understand who is doing what.

bakunin

7

Hi,

Thanks for the reply......can you explain me how internet accessed in 

 the mobile? ..Is it mobile also having modem?

  As far as I know mobile contact to APN--->SGSN--->GGSN......

 Please explain me in briefly.....

Regards,
Jagdish