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Time synchronization
Synchronized time is possible with a z10 BC server in a Sysplex environment using:
v The External Time Reference (ETR) card to connect to a Sysplex Timer
v Server Time Protocol (STP)
v A combination of both features in a Coordinated Timing Network (CTN)
z900 and z800 servers cannot participate in a Sysplex with z10 BC.
Server time protocol
Server Time Protocol (FC 1021) requires no special cables to create timing links
with other servers. Depending on the distance between servers in a timing network,
you may use ISC-3, ICB-3 (not available on z10 BC), ICB-4, or InfiniBand fiber optic
cables to create the Sysplex. STP can be installed on z10 EC, z10 BC, z9 EC, z9
BC, z990, z890, and Coupling Facility servers.
Server Time Protocol (STP) supports two types of Coordinated Timing Networks
(CTNs) : Mixed and STP-only.
v A Mixed CTN is a timing network that contains a collection of servers (CPCs),
v The STP-only CTN is a timing network that contains a collection of servers
Pulse per second
An STP-only CTN has the capability of configuring as its External Time Source
(ETS) a Network Time Protocol (NTP) time server that has a pulse per second
(PPS) output signal. This type of external time device is available worldwide from
several vendors that provide network timing solutions. Typically, the NTP output of
the time server is connected to the support element (SE) LAN, because the NTP
client runs on the SE. The PPS output of the NTP time server is connected to the
PPS input coaxial connector, provided on the External Time Reference (ETR) card
of the System z10 or System z9 server. Note that pulse per second is only available
for System z10 or System z9.
External Time Reference
The External Time Reference function (ETR) is built into the processor, so it has no
separate feature code. The ETR function uses an ESCON cable with an MT-RJ
connector. ETR connects to a Sysplex Timer, which uses an ESCON Duplex
connector. An ESCON Duplex to MT-RJ conversion kit is required. Each ETR
feature should connect to a different Sysplex Timer in an Expanded Availability
configuration.
Connectivity information
v The cable for ETR is multimode 62.5 micron fiber optic
v The cable connector is MT-RJ
v See Planning for Fiber Optic Links (ESCON, FICON, Coupling Links, and Open
v The cable for pulse per second is coaxial.
You are responsible for supplying these cables.
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z10 BC IMPP
and has at least one STP-configured server (CPC) stepping to timing signals
provided by the Sysplex Timer. The CTN ID must have a valid STP network ID
and the ETR network ID must be in the range of 0 to 31.
(CPCs) configured to be in STP timing mode.
System Adapters), GA23-0367, for information about link distances and light loss
budget.
Level 03c, May 2011
®
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