Imagine I have the following:

client1--WAAS1--RouterA--WAN---RouterB---WAAS2--client2

Assume RouterB is configured for wccp.

When client1 sends a packet to client2, I understand that RouterB would process the wccp 'access-list' and verify that the packet is subject to optimization. Then the router would forward the packet to the WAAS2 box for optimization processing. What happens to the packet after that? I understand that would 'go back' to the Router2 for proper routing?

Can someone explain the routing and flow of packets when a Cisco WAAS/wccp is in place?