ISP2

The simplest ISP (upto 100 users)

 +-----------------+
 |                 |
 |   Upstream ISP  |
 |                 |
 +--------+--------+
          |
          |
 +--------+--------+
 |                 |
 |     DIR-100     |  10.0.0.1/16
 |                 |
 +--+-----------+--+
    |           |
    |           |
 +-----------+ +-----------+
 |           | |           |
 | unmanaged | | unmanaged |
 | Switch1   | | Switch4   |
 |           | |           |
 +--+--------+ ++----------+
    |           |
    |           |     10.0.0.0/16
 +--+--+     +--+--+
 |     |     |     |  
 |  C  |     |  C  |
 |  l  |     |  l  |
 |  i  |     |  i  |
 |  e  | ... |  e  |
 |  n  |     |  n  |
 |  t  |     |  t  |
 |  1  |     | 100 |
 |     |     |     |
 +-----+     +-----+



 +  Very cheap hardware
    Deployment very easy


 -  Subscriber base limited
    Tarif options limited (per-day/week/month fee only)
    Maintenance dificult when subscribers grow in number