+* [Bug 2278] ACTS flag3 mismatch between code and driver18.html.
+* Use an enum for the ACTS state table.
+ * html doc reconciliation with DLM's copy.
+ (4.2.7p328) 2012/11/30 Released by Harlan Stenn <stenn@ntp.org>
+ * html doc reconciliation with DLM's copy.
+ (4.2.7p327) 2012/11/29 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2024] Identify Events in the system status word in decode.html.'
+ * [Bug 2040] Provide a command-line option for the identity key bits.
+ * Create loc/darwin for Mac OSX
+ (4.2.7p326) 2012/11/21 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 1214] 'proto: precision = ...' should be at INFO, not NOTICE.
+ * [Bug 2246] Clear sys_leap when voting says to disarm the leap.
+ (4.2.7p325) 2012/11/20 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2202] ntpq.html: there is no "acv" billboard.
+ * [Bug 2306] keep pps hack for Win32 even if user-mode/loopback
+ PPS API is activated on a serial line.
+ (4.2.7p324) 2012/11/19 Released by Harlan Stenn <stenn@ntp.org>
+ * Reinstate doc fix to authentic.html from Mike T.
+ * [Bug 1223] cleanup for rlimit changes.
+ * [Bug 2098] Install DLM's HTML documentation.
+ * [Bug 2306] Added user-mode/loop-back PPS API provider for Win32
+ (4.2.7p323) 2012/11/18 Released by Harlan Stenn <stenn@ntp.org>
+ * html/ updates from Dave Mills.
+ (4.2.7p322) 2012/11/15 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 1223] Allow configurable values for RLIMIT_STACK and
+ RLIMIT_MEMLOCK.
+ * [Bug 1320] Log ntpd's initial command-line parameters. (updated fix)
+ * [Bug 2120] no sysexits.h under QNX.
+ * [Bug 2123] cleanup to html/leap.html.
+ (4.2.7p321) 2012/11/13 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 1320] Log ntpd's initial command-line parameters.
+ (4.2.7p320) 2012/11/12 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 969] Clarify ntpdate.html documentation about -u and ntpd.
+ * [Bug 1217] libisc/ifiter_sysctl.c:internal_current(): Ignore RTM
+ messages with wrong version
+ (4.2.7p319) 2012/11/11 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2296] Fix compile problem with building with old OpenSSL.
+ (4.2.7p318) 2012/11/05 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2301] Remove spurious debug output from ntpq.
+ (4.2.7p317) 2012/11/05 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 922] Allow interspersed -4 and -6 flags on the ntpq command line.
+ (4.2.7p316) 2012/10/27 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2296] Update fix for Bug 2294 to handle --without-crypto.
+ (4.2.7p315) 2012/10/26 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2294] ntpd crashes in FIPS mode.
+ (4.2.7p314) 2012/10/23 Released by Harlan Stenn <stenn@ntp.org>
+ * Document a tricky malloc() of dns_ctx in sntp.
+ (4.2.7p313) 2012/10/23 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2291] sntp should report why it cannot open file.kod.
+ * [Bug 2293] add support for SO_BINTIME, refine support for
+ SO_TIMESTAMPNS (bug 1374)
+ (4.2.7p312) 2012/10/11 Released by Harlan Stenn <stenn@ntp.org>
+ * Clean up testing/debugging of fix for [Bug 938] from sntp/main.c .
+ (4.2.7p311) 2012/10/10 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 938] The argument to the -D flag takes a number, not a string.
+ * [Bug 1013] ntpdate's HTML page claims wrong default version.
+ * [Bug 1374] Support SO_TIMESTAMPNS.
+ (4.2.7p310) 2012/10/09 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 1374] Support SO_TIMESTAMPNS.
+ * [Bug 2266] Remove deprecated refclock_trak.c from Windows Makefile
+ equivalents.
+ * [Bug 2274] Bring libopts/enum.c back to (old) ANSI C compliance.
+ (4.2.7p309) 2012/10/04 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 2287] ntpdate returns 0 even if adjtime() call fails.
+ (4.2.7p308) 2012/09/29 Released by Harlan Stenn <stenn@ntp.org>
+ * CID 97198: Check return from ioctl() calls in refclock_acts.c.
+ (4.2.7p307) 2012/09/29 Released by Harlan Stenn <stenn@ntp.org>
+ * [Bug 1997] Fix sntp broadcast timeouts.
+ * [Bug 2234] Fix incorrect ntptrace html documentation.
+ * [Bug 2262] Install html docs in $htmldir.
+ * Fix typo in html/select.html.
(4.2.7p306) 2012/09/15 Released by Harlan Stenn <stenn@ntp.org>
* [Bug 752] ToS cleanup from Mike Tatarinov.
(4.2.7p305) 2012/09/15 Released by Harlan Stenn <stenn@ntp.org>
</head>
<body>
<h3>NIST/USNO/PTB Modem Time Services</h3>
-<p>Autjhor: David L. Mills (mills@udel.edu)<br>
+<p>Author: David L. Mills (mills@udel.edu)<br>
Last update:
- <!-- #BeginDate format:En2m -->03-Sep-2010 17:59<!-- #EndDate -->
+ <!-- #BeginDate format:En2m -->10-Nov-2012 14:14<!-- #EndDate -->
UTC</p>
<hr>
<h4>Synopsis</h4>
<p>This driver supports the US (NIST and USNO) and European (PTB (Germany), NPL (UK), etc.) modem time services, as well as Spectracom GPS and WWVB receivers connected via a modem. The driver periodically dials a number from a telephone list, receives the timecode data and calculates the local clock correction. It is designed primarily for backup when neither a radio clock nor connectivity to Internet time servers are available. It can also be configured to operate full period.</p>
<p>For best results the indicated time must be corrected for the modem and telephone circuit propagation delays, which can reach 200 ms or more. For the NIST service, corrections are determined automatically by measuring the roundtrip delay of echoed characters. With this service the absolute accuracy is typically a millisecond or two. Corrections for the other services must be determined by other means. With these services variations from call to call and between messages during a call are typically a few milliseconds, occasionally higher.</p>
<p>This driver requires a 9600-bps modem with a Hayes-compatible command set and control over the modem data terminal ready (DTR) control line. The actual line speed ranges from 1200 bps with USNO to 14,400 bps with NIST. The modem setup string is hard-coded in the driver and may require changes for nonstandard modems or special circumstances.</p>
- <p>There are three modes of operation selected by the <tt>mode</tt> keyword in the <tt>server</tt> configuration command. In manual mode (2) the calling program is initiated by setting fudge <tt>flag1</tt>. This can be done manually using <tt>ntpdc</tt>, or by a cron job. In auto mode (0) <tt>flag1</tt> is set at each poll event. In backup mode (1) <tt>flag1</tt> is set at each poll event, but only if no other synchronization sources are available.</p>
- <p>When <tt>flag1</tt> is set, the calling program dials the first number in the list specified by the <tt>phone</tt> command. If the call fails for any reason, the program dials the second number and so on. The phone number is specified by the Hayes ATDT prefix followed by the number itself, including the prefix and long-distance digits and delay code, if necessary. The <tt>flag1</tt> is reset and the calling program terminated if (a) valid clock update has been determined, (b) no more numbers remain in the list, (c) a device fault or timeout occurs or (d) fudge <tt>flag1</tt> is reset manually using <tt>ntpdc</tt>.</p>
+ <p>There are three modes of operation selected by the <tt>mode</tt> keyword in the <tt>server</tt> configuration command. In manual mode (2) the calling program is initiated by setting fudge <tt>flag1</tt>. This can be done manually using <tt>ntpq</tt>, or by a cron job. In auto mode (0) <tt>flag1</tt> is set at each poll event. In backup mode (1) <tt>flag1</tt> is set at each poll event, but only if no other synchronization sources are available.</p>
+ <p>When <tt>flag1</tt> is set, the calling program dials the first number in the list specified by the <tt>phone</tt> command. If the call fails for any reason, the program dials the second number and so on. The phone number is specified by the Hayes ATDT prefix followed by the number itself, including the prefix and long-distance digits and delay code, if necessary. The <tt>flag1</tt> is reset and the calling program terminated if (a) valid clock update has been determined, (b) no more numbers remain in the list, (c) a device fault or timeout occurs or (d) fudge <tt>flag1</tt> is reset manually using <tt>ntpq</tt>.</p>
<p>The driver automatically recognizes the message format of each modem time service. It selects the parsing algorithm depending on the message length. There is some hazard should the message be corrupted. However, the data format is checked carefully and only if all checks succeed is the message accepted. Corrupted lines are discarded without complaint. Once the service is known, the reference identifier for the driver is set to NIST, USNO, PTB or WWVB as appropriate.</p>
-<p>Ordinarily, the serial port is connected to a modem; however, if fudge <tt>flag3</tt> is set, it can be connected directly to a Spectracom WWV or GPS radio for testing or calibration. The Spectracom radio can be connected via a modem if the radio is connfigured to send time codes continuoulsly at 1-s intervals. In principle, fudge <tt>flag2</tt> enables port locking, allowing the modem to be shared when not in use by this driver. At least on Solaris with the current NTP I/O routines, this results in lots of ugly error messages.</p>
+<p>The Spectracom radio can be connected via a modem if the radio is configured to send time codes continuously at 1-s intervals. In principle, fudge <tt>flag2</tt> enables port locking, allowing the modem to be shared when not in use by this driver. At least on Solaris with the current NTP I/O routines, this results in lots of ugly error messages.</p>
<p>The <tt>minpoll</tt> and <tt>maxpoll</tt> keywords of the server configuration command can be used to limit the intervals between calls. The recommended settings are 12 (1.1 hours) for <tt>minpoll</tt> and 17 (36 hours) for <tt>maxpoll</tt>. Ordinarily, the poll interval will start at <tt>minpoll</tt> and ramp up to <tt>maxpoll</tt> in a day or two.</p>
<h4>US Phone Numbers and Formats</h4>
<p>Note: Phone numbers include the entire Hayes modem command, including the <tt>ATDT</tt> and other control codes as may be necessary. For most cases only the <tt>ATDT</tt> may be necessary.</p>
projects / thirdparty / ntp.git / commitdiff
