HP 9000 V2500 SCA Operator's Manual page 39

Overview
V-Class Server Architecture
For X-dimension connections, CTI cables connect to the opposite
controller on the remote cabinet. This means—for X-dimension CTI
connections—memory boards connect in the following pairs: 0 and 2,
1 and 3, 4 and 6, and 5 and 7.
For details on CTI cable connections refer to qualified HP service
personnel.
Chapter 1 17