According to purpose of load sharing using policy server with COPS

["Hideki Shingu" <shingu@nsl.mci.mei.co.jp>]

Could someone please tell me about load sharing in COPS ?

Now assumed that there are some internet domain, and
each policy server (PS) manages one domain.
For example,
PS 1 manages domain 1.
PS 2 manages domain 2.
..................................
PS N manages domain N.

In this condition, if I make a MPLS path or a channel from the edge of
domain A
to the edge of domain C through domain B (domain A is not next to domain C),
it is expected that PSs negotiate each other.
Like PS1 negotiates with PS2, PS2 negotiates with PS3.

But I have no idea how PSs negotiate using COPS or any other protocols,
what kind of COPS messages are used in the negotiation,
what kind of COPS objects, what kind of  routing data..

If someone knows good documents/articles and any other information in
this region, please advise me.

thanks.

Shingu.