On Nov 4, 2008, at 6:08 AM, Steve Anness wrote: > Good Day, > > I have been tasked with fixing the time on our asterisk server. I > am having a hard time finding documentation to tell my what asterisk > uses to get its time information to push to phones (or a better > question, where does the SPA-962 get its time information)? > > Basically, I can go under the settings of the phone and change the > offset to set the correct hour, but it is still about 4 minutes > fast. So the SPA-962 has an offset option, but to offset it from > what? The time on the asterisk server? That isn’t right because my > asterisk server has the correct time. To offset from GMT? No > because I am +6 from GMT not +2. > > I can physically set the time, but that is a bitch when you have > many phones, shouldn’t the phone be syncing with something? > > Any thoughts? I am not finding anything conclusive. > > > Steve Anness > ICT Support Analyst > Humanitarian International Services Group
Your SPA devices almost certainly get their timing data from an NTP server. Some devices will find their NTP servers with DHCP options requests, and I think there is even a Zeroconf method for determining local NTP servers, but I doubt anyone uses that method. One of the more novel methods I used a while ago (when I was doing design for ATAs) was to use the Date: header in the SIP INVITE as the time set. The device would know it's GMT offset, and then calculate what time it was. It was an ugly hack, and that ATA was the reason that the Date: header is in INVITEs in Asterisk. :-) I was kind of ashamed of it a while ago (NTP is much more correct solution) but the more pragmatic I get in my old age, the more elegant it seems. No NTP stack to worry about, no additional firewall holes, etc. etc. and phones really don't need to be super-accurate so NTP is typically overkill anyway. ATAs especially, since they don't even display the date - they just send it along with the Caller ID data when a new call event is generated. JT --- John Todd [EMAIL PROTECTED] +1-256-428-6083 Asterisk Open Source Community Director _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
