IBM Z10 BUISNESS CLASS Z10 BC Reference Manual page 53

z10 Coupling Link Options
Type Description Use Link
data rate
PSIFB 1x IB-DDR LR z10 to z10 5 Gbps
PSIFB 12x IB-DDR z10 to z10 6 GBps
z10 to z9 3 GBps** (492 ft)***
IC Internal Internal Internal
Coupling Communi- Speeds
Channel cation
ICB-4 Copper z10, z9 2 GBps
connection z990, z890
between OS
and CF
ISC-3 Fiber z10, z9 2 Gbps
connection z990, z890
between OS
and CF
• The maximum number of Coupling Links combined cannot exceed 64
per server (PSIFB, ICB-4, ISC-3). There is a maximum of 64 Coupling
CHPIDs (CIB, ICP, CBP, CFP) per server.
• For each MBA fanout installed for ICB-4s, the number of possible cus-
tomer HCA fanouts is reduced by one
* Each link supports defi nition of multiple CIB CHPIDs, up to 16 per fanout
** z10 negotiates to 3 GBps (12x IB-SDR) when connected to a System z9
*** 3 meters (10 feet) reserved for internal routing and strain relief
Note: The Infi niBand link data rates of 6 GBps, 3 GBps, 2.5 Gbps, or 5
Gbps do not represent the performance of the link. The actual performance
is dependent upon many factors including latency through the adapters,
cable lengths, and the type of workload. With Infi niBand coupling links,
while the link data rate may be higher than that of ICB (12x IB-SDR or 12x
IB-DDR) or ISC-3 (1x IB-SDR or 1x IB-DDR), the service times of coupling
operations are greater, and the actual throughput may be less than with ICB
links or ISC-3 links.
Time synchronization and time accuracy on z10 BC
If you require time synchronization across multiple servers
(for example you have a Parallel Sysplex environment) or
you require time accuracy either for one or more System z
servers or you require the same time across heterogeneous
platforms (System z, UNIX, AIX
requirements by either installing a Sysplex Timer Model 2
(9037-002) or by implementing Server Time Protocol (STP).
Distance z10 BC z10
z10 EC Max
Max
10 km unrepeated 12*/32*
(6.2 miles)
100 km repeated
150 meters 12*/32*
N/A 32/32
64
CHPIDS
10 meters*** 12/16
(33 ft)
10 km 48/48
unrepeated
(6.2 miles)
100 km repeated
® , etc.) you can meet these
The Sysplex Timer Model 2 is the centralized time source
that sets the Time-Of-Day (TOD) clocks in all attached
servers to maintain synchronization. The Sysplex Timer
Model 2 provides the stepping signal that helps ensure
that all TOD clocks in a multi-server environment incre-
ment in unison to permit full read or write data sharing with
integrity. The Sysplex Timer Model 2 is a key component of
an IBM Parallel Sysplex environment and a Geographically
Dispersed Parallel Sysplex
for On Demand Business.
The z10 BC server requires the External Time Reference
(ETR) feature to attach to a Sysplex Timer. The ETR fea-
ture is standard on the z10 BC and supports attachment
at an unrepeated distance of up to three kilometers (1.86
miles) and a link data rate of 8 Megabits per second.
The distance from the Sysplex Timer to the server can be
extended to 100 km using qualifi ed Dense Wavelength
Division Multiplexers (DWDMs). However, the maximum
repeated distance between Sysplex Timers is limited to
40 km.
Server Time Protocol (STP)
STP messages: STP is a message-based protocol in
which timekeeping information is transmitted between
servers over externally defi ned coupling links. ICB-4, ISC-
3, and Infi niBand coupling links can be used to transport
STP messages.
Server Time Protocol enhancements
STP confi guration and time information restoration
after Power on Resets (POR) or power outage: This
enhancement delivers system management improvements
by restoring the STP confi guration and time information
after Power on Resets (PORs) or power failure that affects
both servers of a two server STP-only Coordinated Timing
Network (CTN). To enable this function the customer has to
select an option that will assure than no other servers can
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