Subject: [alto] One PID map for all rating criteria?

From: Sebastian Kiesel <[email-masked]>
Date: Tue, 10 Aug 2010 10:47:28 +0200

Hi,

I am wondering about the role of PIDs when multiple rating criteria
are available.

Assume an ISP wants to provide an ALTO server that can give guidance
to its customers based on different rating criteria:

  1) The "lower bound for latency" rating criterion,
     using a sophisticated model of the Internet, based on the AS topology,
     router hop counts, and RTT measurements, which can distinguish
     thousands of different "Internet regions" and give detailed
     rating values for them.

  2) The "relative operator's preference" rating criterion,
     using a simplistic model of the Internet:

     a.b.0.0/16 is our own prefix -> 2 (good)
     p.q.r.0/24 and x.y.z.0/24 are via heavily congested links -> 0 (avoid)
     0.0.0.0/0  rest of the world -> 1 (default)

For 1) we would have to define an extensive PID map with thousands of
PIDs. If an ALTO client is only interested in 2), does it have to
download this extensive PID map as well? How does the ALTO client
know that the extensive PID map is only needed for 1)?

Thanks,
Sebastian