IBM Z10 BUISNESS CLASS Z10 BC - Manual (Page 52)

The IBM System z10 BC also takes advantage of
Infi niBand as a higher-bandwidth replacement for the Self-
Timed Interconnect (STI) I/O interface features found in
prior System z servers.
Infi niBand coupling links are CHPID type CIB.
Coupling Connectivity for Parallel Sysplex
Five coupling link options: The z10 BC supports Internal
Coupling channels (ICs), Integrated Cluster Bus-4 (ICB-4),
InterSystem Channel-3 (ISC-3) (peer mode), and 12x and
1x Infi niBand (IFB) links for communication in a Parallel
Sysplex environment.
1) Internal Coupling Channels (ICs) can be used for inter-
nal communication between Coupling Facilities (CFs)
defi ned in LPARs and z/OS images on the same server.
2) Integrated Cluster Bus-4 (ICB-4) links are for short
distances. ICB-4 links use 10 meter (33 feet) copper
cables, of which 3 meters (10 feet) is used for internal
routing and strain relief. ICB-4 is used to connect z10
BC-to-z10 BC, z10 EC, z9 EC, z9 BC, z990, and z890.
Note: If connecting to a z9 BC or a z10 BC with ICB-4,
those servers cannot be installed with the non-raised
fl oor feature. Also, if the z10 BC is ordered with the non-
raised fl oor feature, ICB-4 cannot be ordered.
3) InterSystem Channel-3 (ISC-3) supports communi-
cation over unrepeated distances of up to 10 km (6.2
miles) using 9 micron single mode fi ber optic cables
and even greater distances with System z qualifi ed opti-
cal networking solutions. ISC-3s are supported exclu-
sively in peer mode (CHPID type CFP).
4) 12x Infi niBand coupling links (12x IB-SDR or 12x
IB-DDR) offer an alternative to ISC-3 in the data center
and facilitate coupling link consolidation; physical links
can be shared by multiple systems or CF images on a
single system. The 12x IB links support distances up to
150 meters (492 feet) using industry-standard OM3 50
micron fi ber optic cables.
System z now supports 12x Infi niBand single data rate
(12x IB-SDR) coupling link attachment between System
z10 and System z9 general purpose (no longer limited to
standalone coupling facility)
5) Long Reach 1x Infi niBand coupling links (1x IB-
SDR or 1x IB-DDR) are an alternative to ISC-3 and
offer greater distances with support for point-to-point
unrepeated connections of up to 10 km (6.2 miles)
using 9 micron single mode fi ber optic cables. Greater
distances can be supported with System z qualifi ed
optical networking solutions. Long reach 1x Infi niBand
coupling links support the same sharing capability as
the 12x Infi niBand version allowing one physical link to
be shared across multiple CF images on a system.
Note: The Infi niBand link data rates do not represent the
performance of the link. The actual performance is depen-
dent upon many factors including latency through the
adapters, cable lengths, and the type of workload. Specifi -
cally, with 12x Infi niBand coupling links, while the link data
rate can be higher than that of ICB, the service times of
coupling operations are greater, and the actual throughput
is less.
Refer to the Coupling Facility Confi guration Options white-
paper for a more specifi c explanation of when to continue
using the current ICB or ISC-3 technology versus migrat-
ing to Infi niBand coupling links.
The whitepaper is available at: http://www.ibm.com/
systems/z/advantages/pso/whitepaper.html.
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