Identifying a Node in MPP

Database

Identifying a Node in MPP

Hi all,
How do the request from the client send to appropriate Node in the MPP system?
The AMP within a Node is identified by Mapping The hash value generated by PE's generator in the Hashmap.
(But the PE is within the Node)So how the Node is identified in the first place?
Also do clarify something on BYNET Node ID.
Thanks in advance,