How do dialup ISPs allow multiple clients under one access number?

Justin M. Streiner streiner at
Mon Nov 24 15:52:17 UTC 2008

On Mon, 24 Nov 2008, John Musbach wrote:

> I'm interested in figuring out how dialup ISPs work and have found
> plenty of info on dialin server setup but not much on how ISPs allow
> multiple clients under one access number, how do they do it?

That depends on what you mean by multiple clients.  If you mean multiple 
customers of a single ISP, you would provision serveral PRIs through a 
telco, and assign a phone number that will hunt down through all of PRIs 
to find an open port.

If you mean multiple clients in the sense that you're a dial wholesaler 
and you're providing service to multiple ISPs, you'd still do hunt groups 
as mentioned by other posters, plus you could also assign each wholesale 
client a unique RADIUS domain to allow for client-specific attributes to 
be applied to dialin sessions.  For example, this could be used to control 
the IP addresses that are assigned a given ISP's customers.


More information about the NANOG mailing list