Yes, we're all converging on the correct answers. Here's a quick summary. There are two supported paths for IBM mainframes to synchronize with an external clock source, and then a few different types of external clocks that can be used. The older option is to install a Sysplex Timer (9037-002) and then connect the Sysplex Timer to an external time reference (ETR) via the 9037 serial port. You can use a dial-up modem (to the U.S. NIST modem pool, for example), a shortwave radio receiver (to NIST's WWV for example), or a GPS receiver. GPS receivers are certainly more in vogue now, and there are several companies building such boxes. Configure everything correctly (including operating systems) and you're all set.
Note that some people have figured out how to use that serial port connection with other devices that could deliver the time information bytes. Not recommended. Support for the 9037-002 will end at some point in the future, so nowadays IBM is recommending STP (Server Time Protocol) which is supported on z890, z990, z9 BC, and z9 EC systems. At present your external time reference would be via dial-up modem to NIST and similar time source modem pools -- that's supported much like the Call Home feature and easy to set up on the HMC. IBM has a Statement of Direction expressing the company's intention to support two more external time sources in the future: GPS and any arbitrary NTP server (NTPD). My hunch is the latter option will come with all sorts of warning statements -- fall victim to time of day spoofing and you could have horrible problems -- but let's leave that aside for now. :-) At present you have two choices for keeping mainframe time in sync with other servers' time clocks: 1. Make the mainframe boss. This is the best choice for a lot of reasons. Set up the mainframe to get its external time reference, then use the built-in time server so that other servers can get time sync over the network, perhaps in a hierarchy. 2. Have both the mainframe and your organization's master time server (if they are unfortunately different entitites) both sync to the same external time reference (such as NIST dial-up). This might not offer as much accuracy, but it might be sufficient for certain purposes. - - - - - Timothy Sipples IBM Consulting Enterprise Software Architect Specializing in Software Architectures Related to System z Based in Tokyo, Serving IBM Japan and IBM Asia-Pacific E-Mail: [EMAIL PROTECTED] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
