1PTP4l(8) System Manager's Manual PTP4l(8)
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6 ptp4l - PTP Boundary/Ordinary/Transparent Clock
7
10 ptp4l [ -AEP246HSLmqsv ] [ -f config ] [ -p phc-device ] [ -l print-
11 level ] [ -i interface ] [ long-options ] ...
12
15 ptp4l is an implementation of the Precision Time Protocol (PTP) accord‐
16 ing to IEEE standard 1588 for Linux. It implements Boundary Clock (BC),
17 Ordinary Clock (OC), and Transparent Clock (TC).
18
21 -A Select the delay mechanism automatically. Start with E2E and
22 switch to P2P when a peer delay request is received.
23 -E Select the delay request-response (E2E) mechanism. This is the
25 default mechanism. All clocks on single PTP communication path
26 must use the same mechanism. A warning will be printed when a
27 peer delay request is received on port using the E2E mechanism.
28 -P Select the peer delay (P2P) mechanism. A warning will be printed
30 when a delay request is received on port using the P2P mecha‐
31 nism.
32 -2 Select the IEEE 802.3 network transport.
34 -4 Select the UDP IPv4 network transport. This is the default
36 transport.
37 -6 Select the UDP IPv6 network transport.
39 -H Select the hardware time stamping. All ports specified by the -i
41 option and in the configuration file must be attached to the
42 same PTP hardware clock (PHC). This is the default time stamp‐
43 ing.
44 -S Select the software time stamping.
46 -L Select the legacy hardware time stamping.
48 -f config
50 Read configuration from the specified file. No configuration
51 file is read by default.
52 -i interface
54 Specify a PTP port, it may be used multiple times. At least one
55 port must be specified by this option or in the configuration
56 file.
57 -p phc-device
59 (This option is deprecated.) Before Linux kernel v3.5 there was
60 no way to discover the PHC device associated with a network
61 interface. This option specifies the PHC device (e.g.
62 /dev/ptp0) to be used when running on legacy kernels.
63 -s Enable the slaveOnly mode.
65 -l print-level
67 Set the maximum syslog level of messages which should be printed
68 or sent to the system logger. The default is 6 (LOG_INFO).
69 -m Print messages to the standard output.
71 -q Don't send messages to the system logger.
73 -v Prints the software version and exits.
75 -h Display a help message.
77
80 Each and every configuration file option (see below) may also appear as
81 a "long" style command line argument. For example, the slaveOnly
82 option may be set using either of these two forms.
83 --slaveOnly 1 --slaveOnly=1
85 Option values given on the command line override values in the global
87 section of the configuration file.
88
91 The configuration file is divided into sections. Each section starts
92 with a line containing its name enclosed in brackets and it follows
93 with settings. Each setting is placed on a separate line, it contains
94 the name of the option and the value separated by whitespace charac‐
95 ters. Empty lines and lines starting with # are ignored.
96 There are three different section types.
98 1. The global section (indicated as [global]) sets the program
101 options, clock options and default port options. Other sections
102 are port specific sections and they override the default port
103 options.
104 2. Port sections give the name of the configured port (e.g.
106 [eth0]). Ports specified in the configuration file don't need
107 to be specified by the -i option. An empty port section can be
108 used to replace the command line option.
109 3. Tables for configuring unicast discovery begin with
111 [unicast_master_table].
112 See UNICAST DISCOVERY OPTIONS, below.
114
117 delayAsymmetry
118 The time difference in nanoseconds of the transmit and receive
119 paths. This value should be positive when the master-to-slave
120 propagation time is longer and negative when the slave-to-master
121 time is longer. The default is 0 nanoseconds.
122 logAnnounceInterval
124 The mean time interval between Announce messages. A shorter
125 interval makes ptp4l react faster to the changes in the master-
126 slave hierarchy. The interval should be the same in the whole
127 domain. It's specified as a power of two in seconds. The
128 default is 1 (2 seconds).
129 logSyncInterval
131 The mean time interval between Sync messages. A shorter interval
132 may improve accuracy of the local clock. It's specified as a
133 power of two in seconds. The default is 0 (1 second).
134 operLogSyncInterval
136 The Sync message interval to be requested once the clock enters
137 the SERVO_LOCKED_STABLE state. If the 'msg_interval_request'
138 option is set, then the local slave port will request the remote
139 master to switch to the given message rate via a signaling mes‐
140 sage containing a Message interval request TLV. This option is
141 specified as a power of two in seconds, and default value is 0
142 (1 second).
143 logMinDelayReqInterval
145 The minimum permitted mean time interval between Delay_Req mes‐
146 sages. A shorter interval makes ptp4l react faster to the
147 changes in the path delay. It's specified as a power of two in
148 seconds. The default is 0 (1 second).
149 logMinPdelayReqInterval
151 The minimum permitted mean time interval between Pdelay_Req mes‐
152 sages. It's specified as a power of two in seconds. The default
153 is 0 (1 second).
154 operLogPdelayReqInterval
156 The Pdelay Request messages interval to be used once the clock
157 enters the SERVO_LOCKED_STABLE state. If the 'msg_inter‐
158 val_request' option is set, then the local slave port will adopt
159 this rate when the local clock enters the "locked stable" state.
160 This option is specified as a power of two in seconds, and the
161 default value is 0 (1 second).
162 inhibit_delay_req
164 Don't send any delay requests. This will need the asCapable con‐
165 fig option to be set to 'true'. This is useful when running as a
166 designated master who does not need to calculate offset from
167 slave. The default is 0 (disabled).
168 announceReceiptTimeout
170 The number of missed Announce messages before the last Announce
171 messages expires. The default is 3.
172 syncReceiptTimeout
174 The number of sync/follow up messages that may go missing before
175 triggering a Best Master Clock election. This option is used for
176 running in gPTP mode according to the 802.1AS-2011 standard.
177 Setting this option to zero will disable the sync message time‐
178 out. The default is 0 or disabled.
179 transportSpecific
181 The transport specific field. Must be in the range 0 to 255.
182 The default is 0.
183 ignore_transport_specific
185 By default, incoming messages are dropped if their transportSpe‐
186 cific field does not match the configured value. However, many
187 of transports specified in the 1588 standard mandate ignoring
188 this field. Moreover, some equipment is known to set the
189 reserved bits. Configuring this option as 1 causes this field
190 to be ignored completely on receive. The default is 0.
191 path_trace_enabled
193 Enable the mechanism used to trace the route of the Announce
194 messages. The default is 0 (disabled).
195 follow_up_info
197 Include the 802.1AS data in the Follow_Up messages if enabled.
198 The default is 0 (disabled).
199 fault_reset_interval
201 The time in seconds between the detection of a port's fault and
202 the fault being reset. This value is expressed as a power of
203 two. Setting this value to -128 or to the special key word
204 "ASAP" will let the fault be reset immediately. The default is
205 4 (16 seconds).
206 fault_badpeernet_interval
208 The time in seconds between the detection of a peer network mis‐
209 configuration and the fault being reset. The port is disabled
210 for the duration of the interval. The value is in seconds and
211 the special key word ASAP will let the fault be reset immedi‐
212 ately. The default is 16 seconds.
213 delay_mechanism
215 Select the delay mechanism. Possible values are E2E, P2P and
216 Auto. The default is E2E.
217 hybrid_e2e
219 Enables the "hybrid" delay mechanism from the draft Enterprise
220 Profile. When enabled, ports in the slave state send their delay
221 request messages to the unicast address taken from the master's
222 announce message. Ports in the master state will reply to uni‐
223 cast delay requests using unicast delay responses. This option
224 has no effect if the delay_mechanism is set to P2P. The default
225 is 0 (disabled).
226 inhibit_multicast_service
228 Some unicast mode profiles insist that no multicast message are
229 ever transmitted. Setting this option inhibits multicast trans‐
230 mission. The default is 0 (mutlicast enabled).
231 net_sync_monitor
233 Enables the NetSync Monitor (NSM) protocol. The NSM protocol
234 allows a station to measure how well another node is synchro‐
235 nized. The monitor sends a unicast delay request to the node,
236 which replies unconditionally with unicast delay response, sync,
237 and follow up messages. If the monitor is synchronized to the
238 GM, it can use the time stamps in the message to estimate the
239 node's offset. This option requires that the 'hybrid_e2e'
240 option be enabled as well. The default is 0 (disabled).
241 unicast_listen
243 When enabled, this option allows the port to grant unicast mes‐
244 sage contracts. Incoming requests for will be granted limited
245 only by the amount of memory available. The default is 0 (dis‐
246 abled).
247 unicast_master_table
249 When set to a positive integer, this option specifies the table
250 id to be used for unicast discovery. Each table lives in its
251 own section and has a unique, positive numerical ID. Entries in
252 the table are a pair of transport type and protocol address.
253 The default is 0 (unicast discovery disabled).
254 unicast_req_duration
256 The service time in seconds to be requested during unicast dis‐
257 covery. Note that the remote node is free to grant a different
258 duration. The default is 3600 seconds or one hour.
259 ptp_dst_mac
261 The MAC address to which PTP messages should be sent. Relevant
262 only with L2 transport. The default is 01:1B:19:00:00:00.
263 p2p_dst_mac
265 The MAC address to which peer delay messages should be sent.
266 Relevant only with L2 transport. The default is
267 01:80:C2:00:00:0E.
268 network_transport
270 Select the network transport. Possible values are UDPv4, UDPv6
271 and L2. The default is UDPv4.
272 neighborPropDelayThresh
274 Upper limit for peer delay in nanoseconds. If the estimated peer
275 delay is greater than this value the port is marked as not
276 802.1AS capable.
277 masterOnly
279 Setting this option to one (1) prevents the port from entering
280 the SLAVE state. In addition, the local clock will ignore
281 Announce messages received on this port. This option's intended
282 use is to support the Telecom Profiles according to ITU-T
283 G.8265.1, G.8275.1, and G.8275.2. The default value is zero or
284 false.
285 G.8275.portDS.localPriority
287 The Telecom Profiles (ITU-T G.8275.1 and G.8275.2) specify an
288 alternate Best Master Clock Algorithm (BMCA) with a unique data
289 set comparison algorithm. The value of this option is associ‐
290 ated with Announce messages arriving on a particular port and is
291 used as a tie breaker whenever clockClass, clockAccuracy, off‐
292 setScaledLogVariance, and priority2 are equal. This option is
293 only used when "dataset_comparison" is set to "telecom". The
294 default value is 128.
295 Warning: the BMCA is guaranteed to produce a spanning tree (that
297 is, a timing network without loops) only when using the default
298 values of G.8275.defaultDS.localPriority and
299 G.8275.portDS.localPriority. Careful network engineering is
300 needed when using non-default values.
301 min_neighbor_prop_delay
303 Lower limit for peer delay in nanoseconds. If the estimated peer
304 delay is smaller than this value the port is marked as not
305 802.1AS capable.
306 tsproc_mode
308 Select the time stamp processing mode used to calculate offset
309 and delay. Possible values are filter, raw, filter_weight,
310 raw_weight. Raw modes perform well when the rate of sync mes‐
311 sages (logSyncInterval) is similar to the rate of delay messages
312 (logMinDelayReqInterval or logMinPdelayReqInterval). Weighting
313 is useful with larger network jitters (e.g. software time stamp‐
314 ing). The default is filter.
315 delay_filter
317 Select the algorithm used to filter the measured delay and peer
318 delay. Possible values are moving_average and moving_median.
319 The default is moving_median.
320 delay_filter_length
322 The length of the delay filter in samples. The default is 10.
323 egressLatency
325 Specifies the difference in nanoseconds between the actual
326 transmission time at the reference plane and the reported trans‐
327 mit time stamp. This value will be added to egress time stamps
328 obtained from the hardware. The default is 0.
329 ingressLatency
331 Specifies the difference in nanoseconds between the reported
332 receive time stamp and the actual reception time at reference
333 plane. This value will be subtracted from ingress time stamps
334 obtained from the hardware. The default is 0.
335 boundary_clock_jbod
337 When running as a boundary clock (that is, when more than one
338 network interface is configured), ptp4l performs a sanity check
339 to make sure that all of the ports share the same hardware clock
340 device. This option allows ptp4l to work as a boundary clock
341 using "just a bunch of devices" that are not synchronized to
342 each other. For this mode, the collection of clocks must be syn‐
343 chronized by an external program, for example phc2sys(8) in
344 "automatic" mode. The default is 0 (disabled).
345 udp_ttl
347 Specifies the Time to live (TTL) value for IPv4 multicast mes‐
348 sages and the hop limit for IPv6 multicast messages. This option
349 is only relevant with the IPv4 and IPv6 UDP transports. The
350 default is 1 to restrict the messages sent by ptp4l to the same
351 subnet.
352
355 twoStepFlag
356 Enable two-step mode for sync messages. One-step mode can be
357 used only with hardware time stamping. The default is 1
358 (enabled).
359 slaveOnly
361 The local clock is a slave-only clock if enabled. The default is
362 0 (disabled).
363 socket_priority
365 Configure the SO_PRIORITY of sockets. This is to support cases
366 where a user wants to route ptp4l traffic using Linux qdiscs for
367 the purpose of traffic shaping. This option is only available
368 with the IEEE 802.3 transport (the -2 option) and is silently
369 ignored when using the UDP IPv4/6 network transports. Must be in
370 the range of 0 to 15, inclusive. The default is 0.
371 gmCapable
373 If this option is enabled, then the local clock is able to
374 become grand master. This is only for use with 802.1AS clocks
375 and has no effect on 1588 clocks. The default is 1 (enabled).
376 priority1
378 The priority1 attribute of the local clock. It is used in the
379 best master selection algorithm, lower values take precedence.
380 Must be in the range 0 to 255. The default is 128.
381 priority2
383 The priority2 attribute of the local clock. It is used in the
384 best master selection algorithm, lower values take precedence.
385 Must be in the range 0 to 255. The default is 128.
386 clockClass
388 The clockClass attribute of the local clock. It denotes the
389 traceability of the time distributed by the grandmaster clock.
390 The default is 248.
391 clockAccuracy
393 The clockAccuracy attribute of the local clock. It is used in
394 the best master selection algorithm. The default is 0xFE.
395 clockIdentity
397 The clockIdentity attribute of the local clock. The clockIden‐
398 tity is an 8-octet array and should in this configuration be
399 written in textual form, see default. It should be unique since
400 it is used to identify the specific clock. If default is used
401 or if not set at all, the clockIdentity will be automtically
402 generated. The default is "000000.0000.000000"
403 offsetScaledLogVariance
405 The offsetScaledLogVariance attribute of the local clock. It
406 characterizes the stability of the clock. The default is
407 0xFFFF.
408 G.8275.defaultDS.localPriority
410 The Telecom Profiles (ITU-T G.8275.1 and G.8275.2) specify an
411 alternate Best Master Clock Algorithm (BMCA) with a unique data
412 set comparison algorithm. The value of this option is associ‐
413 ated with the local clock and is used as a tie breaker whenever
414 clockClass, clockAccuracy, offsetScaledLogVariance, and prior‐
415 ity2 are equal. This option is only used when "dataset_compari‐
416 son" is set to "telecom". The default value is 128.
417 Warning: the BMCA is guaranteed to produce a spanning tree (that
419 is, a timing network without loops) only when using the default
420 values of G.8275.defaultDS.localPriority and
421 G.8275.portDS.localPriority. Careful network engineering is
422 needed when using non-default values.
423 maxStepsRemoved
425 When using this option, if the value of stepsRemoved of an
426 Announce message is greater than or equal to the value of
427 maxStepsRemoved the Announce message is not considered in the
428 operation of the BMCA. The default value is 255.
429 domainNumber
432 The domain attribute of the local clock. The default is 0.
433 utc_offset
435 The current offset between TAI and UTC. The default is 37.
436 free_running
438 Don't adjust the local clock if enabled. The default is 0 (dis‐
439 abled).
440 freq_est_interval
442 The time interval over which is estimated the ratio of the local
443 and peer clock frequencies. It is specified as a power of two in
444 seconds. The default is 1 (2 seconds).
445 assume_two_step
447 Treat one-step responses as two-step if enabled. It is used to
448 work around buggy 802.1AS switches. The default is 0 (dis‐
449 abled).
450 tc_spanning_tree
452 When running as a Transparent Clock, increment the "stepsRe‐
453 moved" field of Announce messages that pass through the switch.
454 Enabling this option ensures that PTP message loops never form,
455 provided the switches all implement this option together with
456 the BMCA.
457 tx_timestamp_timeout
459 The number of milliseconds to poll waiting for the tx time stamp
460 from the kernel when a message has recently been sent. The
461 default is 1.
462 check_fup_sync
464 Because of packet reordering that can occur in the network, in
465 the hardware, or in the networking stack, a follow up message
466 can appear to arrive in the application before the matching sync
467 message. As this is a normal occurrence, and the sequenceID mes‐
468 sage field ensures proper matching, the ptp4l program accepts
469 out of order packets. This option adds an additional check using
470 the software time stamps from the networking stack to verify
471 that the sync message did arrive first. This option is only use‐
472 ful if you do not trust the sequence IDs generated by the mas‐
473 ter. The default is 0 (disabled).
474 clock_servo
476 The servo which is used to synchronize the local clock. Valid
477 values are "pi" for a PI controller, "linreg" for an adaptive
478 controller using linear regression, "ntpshm" for the NTP SHM
479 reference clock to allow another process to synchronize the
480 local clock (the SHM segment number is set to the domain num‐
481 ber), and "nullf" for a servo that always dials frequency offset
482 zero (for use in SyncE nodes). The default is "pi."
483 clock_type
485 Specifies the kind of PTP clock. Valid values are "OC" for
486 ordinary clock, "BC" for boundary clock, "P2P_TC" for peer to
487 peer transparent clock, and "E2E_TC" for end to end transparent
488 clock. An multi-port ordinary clock will automatically be con‐
489 figured as a boundary clock. The default is "OC".
490 pi_proportional_const
492 The proportional constant of the PI controller. When set to 0.0,
493 the proportional constant will be set by the following formula
494 from the current sync interval. The default is 0.0.
495 kp = min(kp_scale * sync^kp_exponent, kp_norm_max / sync)
497 pi_integral_const
499 The integral constant of the PI controller. When set to 0.0, the
500 integral constant will be set by the following formula from the
501 current sync interval. The default is 0.0.
502 ki = min(ki_scale * sync^ki_exponent, ki_norm_max / sync)
504 pi_proportional_scale
506 The kp_scale constant in the formula used to set the propor‐
507 tional constant of the PI controller from the sync interval.
508 When set to 0.0, the value will be selected from 0.7 and 0.1 for
509 the hardware and software time stamping respectively. The
510 default is 0.0.
511 pi_proportional_exponent
513 The kp_exponent constant in the formula used to set the propor‐
514 tional constant of the PI controller from the sync interval.
515 The default is -0.3.
516 pi_proportional_norm_max
518 The kp_norm_max constant in the formula used to set the propor‐
519 tional constant of the PI controller from the sync interval.
520 The default is 0.7
521 pi_integral_scale
523 The ki_scale constant in the formula used to set the integral
524 constant of the PI controller from the sync interval. When set
525 to 0.0, the value will be selected from 0.3 and 0.001 for the
526 hardware and software time stamping respectively. The default
527 is 0.0.
528 pi_integral_exponent
530 The ki_exponent constant in the formula used to set the integral
531 constant of the PI controller from the sync interval. The
532 default is 0.4.
533 pi_integral_norm_max
535 The ki_norm_max constant in the formula used to set the integral
536 constant of the PI controller from the sync interval. The
537 default is 0.3.
538 step_threshold
540 The maximum offset the servo will correct by changing the clock
541 frequency instead of stepping the clock. When set to 0.0, the
542 servo will never step the clock except on start. It's specified
543 in seconds. The default is 0.0. This option used to be called
544 pi_offset_const.
545 first_step_threshold
547 The maximum offset the servo will correct by changing the clock
548 frequency instead of stepping the clock. This is only applied on
549 the first update. It's specified in seconds. When set to 0.0,
550 the servo won't step the clock on start. The default is 0.00002
551 (20 microseconds). This option used to be called pi_f_off‐
552 set_const.
553 max_frequency
555 The maximum allowed frequency adjustment of the clock in parts
556 per billion (ppb). This is an additional limit to the maximum
557 allowed by the hardware. When set to 0, the hardware limit will
558 be used. The default is 900000000 (90%). This option used to
559 be called pi_max_frequency.
560 sanity_freq_limit
562 The maximum allowed frequency offset between uncorrected clock
563 and the system monotonic clock in parts per billion (ppb). This
564 is used as a sanity check of the synchronized clock. When a
565 larger offset is measured, a warning message will be printed and
566 the servo will be reset. When set to 0, the sanity check is dis‐
567 abled. The default is 200000000 (20%).
568 initial_delay
570 The initial path delay of the clock in nanoseconds used for syn‐
571 chronization of the clock before the delay is measured using the
572 E2E or P2P delay mechanism. If set to 0, the clock will not be
573 updated until the delay is measured. The default is 0.
574 ntpshm_segment
576 The number of the SHM segment used by ntpshm servo. The default
577 is 0.
578 udp6_scope
580 Specifies the desired scope for the IPv6 multicast messages.
581 This will be used as the second byte of the primary address.
582 This option is only relevant with IPv6 transport. See RFC 4291.
583 The default is 0x0E for the global scope.
584 uds_address
586 Specifies the address of the UNIX domain socket for receiving
587 local management messages. The default is /var/run/ptp4l.
588 dscp_event
590 Defines the Differentiated Services Codepoint (DSCP) to be used
591 for PTP event messages. Must be a value between 0 and 63. There
592 are several media streaming standards out there that require
593 specific values for this option. For example 46 (EF PHB) in
594 AES67 or 48 (CS6 PHB) in RAVENNA. The default is 0.
595 dscp_general
597 Defines the Differentiated Services Codepoint (DSCP) to be used
598 for PTP general messages. Must be a value between 0 and 63.
599 There are several media streaming standards out there that rec‐
600 ommend specific values for this option. For example 34 (AF41
601 PHB) in AES67 or 46 (EF PHB) in RAVENNA. The default is 0.
602 dataset_comparison
604 Specifies the method to be used when comparing data sets during
605 the Best Master Clock Algorithm. The possible values are
606 "ieee1588" and "G.8275.x". The default is "ieee1588".
607 logging_level
609 The maximum logging level of messages which should be printed.
610 The default is 6 (LOG_INFO).
611 message_tag
613 The tag which is added to all messages printed to the standard
614 output or system log. The default is an empty string (which
615 cannot be set in the configuration file as the option requires
616 an argument).
617 verbose
619 Print messages to the standard output if enabled. The default
620 is 0 (disabled).
621 use_syslog
623 Print messages to the system log if enabled. The default is 1
624 (enabled).
625 summary_interval
627 The time interval in which are printed summary statistics of the
628 clock. It is specified as a power of two in seconds. The statis‐
629 tics include offset root mean square (RMS), maximum absolute
630 offset, frequency offset mean and standard deviation, and path
631 delay mean and standard deviation. The units are nanoseconds and
632 parts per billion (ppb). If there is only one clock update in
633 the interval, the sample will be printed instead of the statis‐
634 tics. The messages are printed at the LOG_INFO level. The
635 default is 0 (1 second).
636 time_stamping
638 The time stamping method. The allowed values are hardware, soft‐
639 ware and legacy. The default is hardware.
640 productDescription
642 The product description string. Allowed values must be of the
643 form manufacturerName;modelNumber;instanceIdentifier and contain
644 at most 64 utf8 symbols. The default is ";;".
645 revisionData
647 The revision description string which contains the revisions for
648 node hardware (HW), firmware (FW), and software (SW). Allowed
649 values are of the form HW;FW;SW and contain at most 32 utf8 sym‐
650 bols. The default is an ";;".
651 userDescription
653 The user description string. Allowed values are of the form
654 name;location and contain at most 128 utf8 symbols. The default
655 is an empty string.
656 manufacturerIdentity
658 The manufacturer id which should be an OUI owned by the manufac‐
659 turer. The default is 00:00:00.
660 kernel_leap
662 When a leap second is announced, let the kernel apply it by
663 stepping the clock instead of correcting the one-second offset
664 with servo, which would correct the one-second offset slowly by
665 changing the clock frequency (unless the step_threshold option
666 is set to correct such offset by stepping). Relevant only with
667 software time stamping. The default is 1 (enabled).
668 timeSource
670 The time source is a single byte code that gives an idea of the
671 kind of local clock in use. The value is purely informational,
672 having no effect on the outcome of the Best Master Clock algo‐
673 rithm, and is advertised when the clock becomes grand master.
674 hwts_filter
676 Select the hardware time stamp filter setting mode. Possible
677 values are normal, check, full. Normal mode set the filters as
678 needed. Check mode only check but do not set. Full mode set
679 the receive filter to mark all packets with hardware time stamp,
680 so all applications can get them. The default is normal.
681 asCapable
683 If set to 'true', all the checks which can unset asCapable vari‐
684 able (as described in Section 10.2.4.1 of 802.1AS) are skipped.
685 If set to 'auto', asCapable is initialized to 'false' and will
686 be set to 'true' after the relevant checks have passed. The
687 default value is 'auto'.
688 BMCA This option enables use of static roles for master and slave
690 devices instead of running the best master clock algorithm
691 (BMCA) described in 1588 profile. This is useful when you know
692 the roles of the devices in advance. When set to ´noop', the
693 traditional BMCA algorithm used by 1588 is skipped. masterOnly
694 and slaveOnly will be used to determine master or slave role for
695 the device. In a bridge, slaveOnly (which is a global option)
696 can be set to make all ports assume the slave role. masterOnly
697 (which is a per-port config option) can then be used to set
698 individual ports to take master role. BMCA is used in the Auto‐
699 motive profile to speed up the start time for grand master and
700 slaves. The default value is 'ptp' which runs the BMCA related
701 state machines.
702 inhibit_announce
704 This will disable the timer for announce messages (i.e.
705 FD_MANNO_TIMER) and also the announce message timeout timer
706 (i.e. FD_ANNOUNCE_TIMER). This is used by the Automotive profile
707 as part of switching over to a static BMCA. if this option is
708 enabled, ignore_source_id has to be enabled in the slave because
709 it has no way to identify master identity in Sync and Follow_Up
710 messages. The default is 0 (disabled).
711 ignore_source_id
713 This will disable source port identity checking for Sync and
714 Follow_Up messages. This is useful when the announce messages
715 are disabled in the master and the slave does not have any way
716 to know it's identity. The default is 0 (disabled).
717 msg_interval_request
719 This option, when set, will trigger an adjustment to the Sync
720 and peer delay request message intervals when the clock servo
721 transitions into the SERVO_LOCKED_STABLE state. The Sync inter‐
722 val will be adjusted via the signaling mechanism while the pde‐
723 lay request interval is simply adjusted locally. The values to
724 use for the new Sync and peer delay request intervals are speci‐
725 fied by the operLogSyncInterval and operLogPdelayReqInterval
726 options, respectively. The default value of msg_inter‐
727 val_request is 0 (disabled).
728 servo_num_offset_values
730 The number of offset values considered in order to transition
731 from the SERVO_LOCKED to the SERVO_LOCKED_STABLE state. The
732 transition occurs once the last 'servo_num_offset_values' off‐
733 sets are all below the 'servo_offset_threshold' value. The
734 default value is 10.
735 servo_offset_threshold
737 The offset threshold used in order to transition from the
738 SERVO_LOCKED to the SERVO_LOCKED_STABLE state. The transition
739 occurs once the last The default value of offset_threshold is 0
740 (disabled).
741 slave_event_monitor
743 Specifies the address of a UNIX domain socket for slave event
744 monitoring. A local client bound to this address will receive
745 SLAVE_RX_SYNC_TIMING_DATA and SLAVE_DELAY_TIMING_DATA_NP TLVs.
746 The default is the empty string (disabled).
747 write_phase_mode
749 This option enables using the "write phase" feature of a PTP
750 Hardware Clock. If supported by the device, this mode uses the
751 hardware's built in phase offset control instead of frequency
752 offset control. The default value is 0 (disabled).
753
756 table_id
757 Each table must begin with a unique, positive table ID. The
758 port that claims a given table does so by including the ID as
759 the value of its 'unicast_master_table' option.
760 logQueryInterval
762 This option configures the time to wait between unicast negotia‐
763 tion attempts. It is specified as a power of two in seconds.
764 The default is 0 (1 second).
765 peer_address
767 This option specifies the unicast address of the peer for use
768 with the peer to peer delay mechanism. If specified, the port
769 owning the table will negotiate unicast peer delay responses
770 from the machine at the given remote address, otherwise the port
771 will send multicast peer delay requests.
772 L2|UDPv4|UDPv6
774 Each table entry specifies the transport type and network
775 address of a potential remote master. If multiple masters are
776 specified, then unicast negotiation will be performed with each
777 if them.
778
781 ptp4l as domain master either uses PTP or UTC time scale depending on
782 time stamping mode. In software and legacy time stamping modes it
783 announces Arbitrary time scale mode, which is effectively UTC here, in
784 hardware time stamping mode it announces use of PTP time scale.
785 When ptp4l is the domain master using hardware time stamping, it is up
787 to phc2sys to maintain the correct offset between UTC and PTP times.
788 See phc2sys(8) manual page for more details.
789
792 pmc(8), phc2sys(8)
793linuxptp April 2018 PTP4l(8)