IBM z13s Technical Manual page 205

To eliminate any single points of failure in a Parallel Sysplex configuration, have at least the
following components:
Two coupling links between the z/OS and coupling facility images.
Two coupling facility images not running on the same server.
One stand-alone coupling facility. If using system-managed CF structure duplexing or
resource sharing
running with
Coupling link features
The z13s servers support three types of coupling link options:
HCA3-O fanout for 12x InfiniBand, FC 0171
HCA3-O LR fanout for 1x InfiniBand, FC 0170
ICA SR fanout, FC0172
Various link options are available to connect a z13s server to other z Systems and
zEnterprise servers:
ICA SR fanout at 8 GBps to z13 or z13s servers
12x InfiniBand using HCA3-O fanout at 6 GBps to z13 server with HCA3-O fanout, or
z13s, zEC12, zBC12, z196, and z114 servers with HCA3-O or HCA2-O fanout
1x InfiniBand using HCA3-O LR fanout at 5.0 or 2.5 Gbps to z13 server with HCA3-O LR,
or z13s, zEC12, zBC12, z196, and z114 servers with HCA3-O LR or HCA2-O LR fanout
HCA3-O fanout for 12x InfiniBand (FC 0171)
For more information, see 4.6.4, "HCA3-O (12x IFB) fanout (FC 0171)" on page 150.
HCA3-O LR fanout for 1x InfiniBand (FC 0170)
For more information, see 4.6.5, "HCA3-O LR (1x IFB) fanout (FC 0170)" on page 151.
ICA SR fanout (FC0172)
For more information, see 4.6.3, "Integrated Coupling Adapter (FC 0172)" on page 149.
Extended distance support
For extended distance support, see the System z End-to-End Extended Distance Guide,
SG24-8047.
Internal coupling links
IC links are LIC-defined links that connect a CF to a z/OS LPAR in the same server. These
links are available on all z Systems servers. The IC link is a z Systems server coupling
connectivity option that enables high-speed, efficient communication between a CF partition
and one or more z/OS LPARs that run on the same server. The IC is a linkless connection
(implemented in Licensed Internal Code (LIC)), and so does not require any hardware or
cabling.
An IC link is a fast coupling link that uses memory-to-memory data transfers. IC links do not
have PCHID numbers, but do require CHPIDs.
IC links require an ICP channel path definition at the z/OS and the CF end of a channel
connection to operate in peer mode. They are always defined and connected in pairs. The IC
link operates in peer mode, and its existence is defined in HCD/IOCP.
IC links have the following attributes:
Operate in peer mode (channel type ICP) on z Systems servers.
only, a stand-alone coupling facility is not mandatory.
Chapter 4. Central processor complex I/O system structure
177