IBM RS/6000 SP Handbook page 162

2. Configure Service Director on each Clustered Enterprise Server to forward
messages to the local Service Director server. The modem supplied with the
server is not used.
3. Configure Service Director on the local Service Director server to forward
messages received from the Clustered Enterprise Server. The Service
Director modem for the CES system is attached to the control workstation.
IBM intents to replace Service Director with Electronic Service Agent.
Note: Refer Appendix C, "SP system upgrades" on page 407 for more details
about Service Director and Electronic Service Agent.
138 RS/6000 SP and Clustered IBM ^ pSeries Systems Handbook