Peering Traffic

[Durga P Gangisetti <dgangise () osf1 gmu edu>]

HI,

A quick question.
(Q) What percentage of the customer traffic uses the peering links in the
    case of a TIER - I service provider?

    TIER-I Servier providers can be Sprint, BBN, UUnet, AT&T and others.

I know that it might depend on the service provider(ISP) individually
a/c to peering policies. But an approximate percentage like 40,60,80...
will be helpful. Remember that certain percentage of traffic just doesn't 
leave the network -or - remains within the network.

IMP: Assume all the peering traffic is 100% customer traffic ONLY.

BTW, the definition of "peering" being an exchange of traffic between ISPs
without exchange of money.

Thank you,
DurgaPrasad V Gangisetti.