IBM RS/6000 SP Handbook page 154

2. You must make several cable connections. Since the CES may require
multiple RS-232 connections, you must use a multi-port asynchronous
adapter inside the CWS. Do not use the integrated Ethernet for your SP LAN.
3. Some of the cables used with the CES have limited length. Those lengths,
along with the vertical parts of the cable runs, limit the location of the servers
in relation to the other system equipment.
Clustered Enterprise Server switch adapter requirements
If you install a Clustered Enterprise Server into a CES system that uses an SP
Switch, you must install an SP Switch adapter in that server. The adapter you
use to connect the Clustered Enterprise Server to the SP Switch is the RS/6000
SP System Attachment adapter (F/C 8396). Because the RS/6000 SP System
Attachment adapter is not an SP system adapter, you must order it using an
RS/6000 feature code.
The adapter uses an SP Switch cable to connect to an available switch port on a
9076-555 Stand-alone SP Switch for Clustered Nodes.
The model 555 is a tall frame with an integral SEPBU power supply and SP
Switch (F/C 4011), but no processor nodes. This frame provides node
interconnectivity in a CES system having configurations of 2 to 16 servers. By
adding a second SP Switch (F/C 4011) on the 9076-555 Stand-alone SP Switch,
the configuration will be extended with a Tall frame (F/C 1550), which will host
the second SP Switch, and the interconnectivity in CES system will be increased
up to 32 servers. If the 9076-555 is configured with two SP Switches (two F/C
4011), then the 16 switch-to-switch cables must be ordered with the 9076-555.
RS/6000 Server Attached Node (F/C 9122), which has to be ordered on the
9076-555 Stand-alone SP Switch, counts the number of RS/6000 Server
Attached Nodes configured on the CES system (up to 16/32 Clustered
Enterprise Servers). Every RS/6000 Server attached node (F/C 9122) selected
generates an RS/6000 Server Frame Attachment (F/C 9123).
The RS/6000 SP System Attachment adapter requires, for 7017 models, three
media card slots (slot 9-11) in the primary (first) I/O drawer of the SP-attached
server. For 7026 models, two media card slots (slot 6-7) are required in the
primary drawer.
If you attach an existing Enterprise Server to a CES system, you might find SCSI
adapters installed in these slots. These SCSI adapter must be relocated (if
supported on the SP environment).
130 RS/6000 SP and Clustered IBM ^ pSeries Systems Handbook