Charles, that is true ... some S1 clocks do have restrictions (closed access) or even throttling mechs for the Open Access ones ...... however, to this day I have never had an issue and I have had some pretty large uc deployments using this method. I particularly love HE servers. Now mind you, I don't point UC apps directly to S1 clocks, I point them to an internal clock that uses an S1 reference (as shown in the drawing). I only use the S1 clocks as references for requests coming from my UC networks. For general data networks I ensure it uses an S2 or S3 clock or throw it to the wolves with Window server NTP / the pool.
________________________________ From: cisco-voip <[email protected]> on behalf of Charles Goldsmith <[email protected]> Sent: Monday, May 8, 2017 10:52 AM To: Haas, Neal Cc: [email protected] Subject: Re: [cisco-voip] CCX and NTP To expand on this, I would point to your voice gateways with everything internal, then the voice gateways would either use an on-prem NTP server that is radio sync'd or one that Neal has advised. That way, everything is synced together with the same source. For UCCX and other apps, I point them to the UCM pub and the pub points to the voice gateways. I've seen a lot of people advise for pool.ntp.org<http://pool.ntp.org>, but that has bitten me. How often does an NTP process refresh from DNS? I suspect only on reboot or a restart of the NTP process. I've seen too many NTP servers go offline when using the pool addresses. Because of that, I've been sticking with .gov based NTP on the voice gateway. Ryan Huff, one thing about pointing to strata 1 servers, most of them have restrictions from what I've seen, while they work, they could block you for not being approved if you send too many requests. http://support.ntp.org/bin/view/Servers/StratumOneTimeServers has a list, and while many have open access listed, if you look at the details, they can still have restrictions. Just food for thought. On Mon, May 8, 2017 at 9:20 AM, Haas, Neal <[email protected]<mailto:[email protected]>> wrote: Get an on-prem NTP server, if you cant spend the money, use: time.nist.gov<http://time.nist.gov> global address for all servers Multiple locations utcnist.colorado.edu<http://utcnist.colorado.edu> 128.138.140.44 University of Colorado, Boulder utcnist2.colorado.edu<http://utcnist2.colorado.edu> 128.138.141.172 University of Colorado, Boulder time-nw.nist.gov<http://time-nw.nist.gov> 131.107.13.100 Microsoft, Redmond, Washington Really, anything with a GOV, or EDU should be good. By the way, you should NEVER, EVER, EVER (can’t stress this enough) a Windows Based NTP. Every place that I have went into and removed a Windows Time server, everything has worked better! Windows just cant do time. I went into a business with windows NTP, and the guy was checking time from about 100 NTP servers, his time was off by three minutes. Took it down to 3 and everything started to work. Thank You, Neal Haas From: cisco-voip [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Ben Amick Sent: Monday, May 8, 2017 7:12 AM To: [email protected]<mailto:[email protected]> Subject: [cisco-voip] CCX and NTP What do you guys use for NTP on your CCX hosts? I’ve been informed by TAC that “CCX does not support Windows based NTP” so I was thinking about just pointing NTP towards my CCM hosts – is that a valid scenario? I figure that since CCM is pretty much authoritative on everything for CCX as it is it wouldn’t be a problem? Ben Amick Telecom Analyst Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you _______________________________________________ cisco-voip mailing list [email protected]<mailto:[email protected]> https://puck.nether.net/mailman/listinfo/cisco-voip
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