transit provider definition

[Joe Abley <jabley@nlri.org>]

3. Clarification of the definition of "transit provider", since
it was evident that this term is understood differently by many
different people. I have chosen to clarify the definition I used
previously rather than change it. If the definition below is not
sufficiently familiar to enough people, an alternative would be
welcomed.

  I toyed with the idea of including a diagram here, since it seemed
  to help before. For example, in the following picture:

      S0 --- S1 --- S2 --- S3 --- Rest of World
       |            ||      |
       `---- S4 ====='      |            ----- transit circuit
              |             |            ===== peering circuit
              `-------------'

    S1, S4 are transit providers for S0
    S2 is a transit provider of S1
    S3 is a transit provider of S2 and S4

  I toyed with the idea of using "global transit provider", and
  introducing the idea that S2 was a transit provider for S4 to
  S1 and S0 only, whilst S3 was a global transit provider for
  S4. However, the definition is woolly enough already, and I
  thought I would avoid any unnecessary confusion by not raising
  the issue.

Comments and suggestions for improvement very welcome.


>  2. Terminology
>  
> [snip]
>
> |   A "transit provider" operates a site which directly provides
> |   connectivity to the Internet to one or more external sites.  The
> |   connectivity provided extends beyond the transit provider's own site.
> |   A transit provider's site is directly connected to the sites for
> |   which it provides transit.