Re:Some DNS lookups causing 5xx errors due to leap second bug
by imglorp on Sunday January 01, 2017 @10:06AM
(#13295940)
But yet, parent poster's phone dropped, so that migration from UTC=GPS+N to UTC=GPS+N+1 would result in the same conniptions we all have to deal with an extra second in the day. Even if it is at the phone's presentation layer, that's several GB of software that might hold lurking N+1 bugs causing the data layer to drop.
Re:Some DNS lookups causing 5xx errors due to leap second bug
by user5994461 on Sunday January 01, 2017 @03:03PM
(#13297041)
Let's reframe that: His phone dropped on the new year, when everyone is sending a happy new year message to everyone they know.
No link with leap second till proven.
Re:Some DNS lookups causing 5xx errors due to leap second bug
by askbjoernhansen on Monday January 02, 2017 @07:40AM
(#13300824)
It wasn't midnight anywhere with CDMA service when the leap second happened.
Re:Some DNS lookups causing 5xx errors due to leap second bug
by kevin_nisbet on Sunday January 01, 2017 @11:42AM
(#13296231)
Agreed, while the CDMA specification requires tight time syncing, like everything else the UNIX OSs used to run the equipment can receive the leap indicator. Any problem within the OS, or the software reading date/time from the OS can cause instability.
Also, without knowing more about what exactly went wrong with your phone, it's possible other infrastructure within the network was unstable, signalling equipment, etc. I can't remember exactly, but I think some of the CDMA equipment at my previous company had a leap second problem previously. And the equipment is no longer being maintained or patched really.
Re:Some DNS lookups causing 5xx errors due to leap second bug
by imglorp on Sunday January 01, 2017 @12:41PM
(#13296441)
Past life $work made UTDOA equipment for GSM networks. The hardware used a number of GPS modules from various vendors to obtain GPS time, which someone noted above includes leap offset broadcast in the periodic almanac.
Anyway, of three different module vendors, two got leap handling wrong. Then our own code had its own leap bugs, on top of the OS (Solaris) timekeeping bugs such as clock jumps and timezone update issues. Good times.
Re:Some DNS lookups causing 5xx errors due to leap second bug
by nullc on Tuesday January 03, 2017 @09:31PM
(#13315203)
Some GPSDO that are used to time CDMA base stations are known to misbehave around leap seconds (though often when the GPS signal sends the leapsecond warning, not at the leapsecond itself).
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3GPP2 C.S0002-A section 1.3 "CDMA System Time":
All base station digital transmissions are referenced to a common CDMA system-wide time scale that uses the Global Positioning System (GPS) time scale, which is traceable to, and synchronous with, Universal Coordinated Time (UTC). GPS and UTC differ by an integer number of seconds, specifically the number of leap second corrections added to UTC since January 6, 1980. The start of CDMA System Time is January 6, 1980 00:00:00 UTC, which coincides with the start of GPS time.
System Time keeps track of leap second corrections to UTC but does not use these corrections for physical adjustments to the System Time clocks.
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I'm pretty sure the only use of leap seconds in CDMA is for converting system time to customary local time, along with the daylight-time indicator and time-zone offset also contained in the sync channel message.
Edit: C.S0005-E section 2.6.1.3 says the mobile station shall store most of the fields of the sync channel message; it may store leap second count, local time offset, and daylight time indicator. This suggests that these fields aren't really that important for talking CDMA.