The HMC modem dial-out feature for time synchronization supports three protocols: NIST Automated Computer Time Service (ACTS), IEN Telephone Date Code (CTD), and NRC Canadian Time Service (CTS). It also supports primary and backup time sources. I would recommend you configure (and test) both and choose different time agencies for each.
1. For NIST ACTS you can try the following modem dial-up telephone numbers: NIST Colorado: +1 303 494 4774 NIST Hawaii: +1 808 335 4721 Speculatively, you could try the U.S. Naval Observatory modem dial-up numbers: USNO D.C.: +1 202 762 1594 USNO Colorado: +1 719 567 6743 The USNO format is a bit different but might still get parsed correctly by the HMC. (Test it first, of course -- I haven't tried this.) Please note that the USNO is 1200 baud (8N1) only. As I write this all 4 numbers are answering the line with modem signaling, but I do not have the equipment to test them on my end. It's quite possible NIST is answering the line but not providing actual time information over the line because they cannot assure it with the partial U.S. government shutdown. 2. The IEN Telephone Date Code (Codice Telefonico di Data) is used by Italy's "Galileo Ferrais" time service which used to be run by the Istituto Elettrotecnico Nazionale. In 2006 the IEN became part of the Istituto Nationale di Ricera Metrologica. You can get more information on that service (including dial-up phone numbers) here: http://www.inrim.it/res/tf/ctd_i.shtml That page is in Italian. The country code for Italy is 39, so it looks like INRM has already formatted the phone numbers for typical North American dialing patterns, but please do test that of course. (And please triple check all of these phone numbers. You don't want to be waking somebody's mother at ~3:00 a.m. local time.) 3. More information on the Canadian time service is available here: http://www.nrc-cnrc.gc.ca/eng/services/time/time_date.html Their dial-up number is +1 613 745 3900. Service is at 300 baud (8N1). If you're in the U.S. it'd probably make a lot of sense to use NIST as primary and NRC as backup. Conversely, if you're in Canada, NRC would be primary with NIST as backup. In Europe you'd probably use IEN (INRM) as primary and either NIST or NRC as backup. If you're in Asia then you'd probably use NIST Hawaii as primary and IEN/INRM as backup. But this is entirely up to you. Or if you need a U.S.-only solution then you could try NIST Colorado and NIST Hawaii as primary/backup or NIST as primary and USNO as backup (assuming USNO actually works -- haven't tried it). Many variations are possible across the 4 agencies and 3 countries. If anyone has tested the USNO and other modem time signal providers, please post a follow-up. Of course the satellite navigation constellations are operating, so if you're getting time signals via satellite (and thence via NTP) you should be fine. For those of you who have already made the move to external time sources via NTP, congratulations. However, time source and path redundancy is still important. It's remotely possible that a specific satellite constellation could be offline, for example, so it'd be nice to have a backup source. -------------------------------------------------------------------------------------------------------- Timothy Sipples GMU VCT Architect Executive (Based in Singapore) E-Mail: [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
