<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div><blockquote type="cite" class=""><div class="">On Jul 11, 2019, at 11:23 AM, Mike Hammett <<a href="mailto:nanog@ics-il.net" class="">nanog@ics-il.net</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: arial, helvetica, sans-serif; font-size: 10pt;" class="">I'll look into Meinberg.<div class=""><br class=""></div><div class="">I recent thread mentioned high-sensitivity receivers often allow GPS to work inside. Obviously "inside" has a lot of definitions.</div><div class=""><br class=""></div><div class="">I will need this facility for the TDM timing signals. It's a central office, not a datacenter.</div><div class=""><br class=""></div><div class="">I don't know that Internet-based NTP would be accurate enough for the timing signals that I need. Maybe, maybe not.</div><div class=""><br class=""></div></div></div></blockquote></div><div>My experience with Dave Mills NTP algorithm is that, giving sufficient diversity in higher stratum sources, GPS versus Internet sources makes no practical difference. This assumes that you are concerned with Time for event logging and scheduling and not concerned with frequency and phase for clocking data on TDM instances.</div><div><br class=""></div><div>If you are worrying about backhoe fade — it’s consequences will most likely affect other things more strongly than Time differences.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; border-spacing: 0px; -webkit-text-decorations-in-effect: none;"><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; border-spacing: 0px; -webkit-text-decorations-in-effect: none;"><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; font-size: 12px; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; -webkit-text-decorations-in-effect: none;"><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; -webkit-text-decorations-in-effect: none;"><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; -webkit-text-decorations-in-effect: none;"><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">James R. Cutler</div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><a href="mailto:James.cutler@consultant.com" class="">James.cutler@consultant.com</a></div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">GPG keys: <a href="hkps://hkps.pool.sks-keyservers.net" class="">hkps://hkps.pool.sks-keyservers.net</a></div></div><br class="Apple-interchange-newline"></span></span></span></span><br class="Apple-interchange-newline"></span></div></div></div></div><div><br class=""><blockquote type="cite" class=""></blockquote></div></div></body></html>