Performance metrics used in commercial BGP route optimizers

[Dimeji Fayomi <oof1 () students waikato ac nz>]

Hi,
I'm doing a research on BGP route optimisation and the performance metrics
used by commercial route optimizer appliances to select better path to a
prefix.

I would appreciate any information about the performance metrics used in
commercial BGP route optimizers, white papers or any other document that
describes how these metrics are measured and collected by commercial route
optimizers.

Thanks
-- 
Dimeji Fayomi