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 mean time interval between Sync messages. This value is only
137 used by the slave device when interval_update_timer is enabled.
138 Slave will send this interval to the master to switch to. This
139 is done via a signaling message after interval_update_timer
140 expires. It's specified as a power of two in seconds. The
141 default value is 0 (1 second).
142 logMinDelayReqInterval
144 The minimum permitted mean time interval between Delay_Req mes‐
145 sages. A shorter interval makes ptp4l react faster to the
146 changes in the path delay. It's specified as a power of two in
147 seconds. The default is 0 (1 second).
148 logMinPdelayReqInterval
150 The minimum permitted mean time interval between Pdelay_Req mes‐
151 sages. It's specified as a power of two in seconds. The default
152 is 0 (1 second).
153 operLogPdelayReqInterval
155 The mean time interval between Pdelay Request messages. This
156 value is only used by the slave device when inter‐
157 val_update_timer is enabled. Slave will switch to the interval
158 specified by this config option after the interval_update_timer
159 expires. It's specified as a power of two in seconds. The
160 default value is 0 (1 second).
161 inhibit_delay_req
163 Don't send any delay requests. This will need the asCapable con‐
164 fig option to be set to 'true'. This is useful when running as a
165 designated master who does not need to calculate offset from
166 slave. The default is 0 (disabled).
167 announceReceiptTimeout
169 The number of missed Announce messages before the last Announce
170 messages expires. The default is 3.
171 syncReceiptTimeout
173 The number of sync/follow up messages that may go missing before
174 triggering a Best Master Clock election. This option is used for
175 running in gPTP mode according to the 802.1AS-2011 standard.
176 Setting this option to zero will disable the sync message time‐
177 out. The default is 0 or disabled.
178 transportSpecific
180 The transport specific field. Must be in the range 0 to 255.
181 The default is 0.
182 ignore_transport_specific
184 By default, incoming messages are dropped if their transportSpe‐
185 cific field does not match the configured value. However, many
186 of transports specified in the 1588 standard mandate ignoring
187 this field. Moreover, some equipment is known to set the
188 reserved bits. Configuring this option as 1 causes this field
189 to be ignored completely on receive. The default is 0.
190 path_trace_enabled
192 Enable the mechanism used to trace the route of the Announce
193 messages. The default is 0 (disabled).
194 follow_up_info
196 Include the 802.1AS data in the Follow_Up messages if enabled.
197 The default is 0 (disabled).
198 fault_reset_interval
200 The time in seconds between the detection of a port's fault and
201 the fault being reset. This value is expressed as a power of
202 two. Setting this value to -128 or to the special key word
203 "ASAP" will let the fault be reset immediately. The default is
204 4 (16 seconds).
205 fault_badpeernet_interval
207 The time in seconds between the detection of a peer network mis‐
208 configuration and the fault being reset. The port is disabled
209 for the duration of the interval. The value is in seconds and
210 the special key word ASAP will let the fault be reset immedi‐
211 ately. The default is 16 seconds.
212 delay_mechanism
214 Select the delay mechanism. Possible values are E2E, P2P and
215 Auto. The default is E2E.
216 hybrid_e2e
218 Enables the "hybrid" delay mechanism from the draft Enterprise
219 Profile. When enabled, ports in the slave state send their delay
220 request messages to the unicast address taken from the master's
221 announce message. Ports in the master state will reply to uni‐
222 cast delay requests using unicast delay responses. This option
223 has no effect if the delay_mechanism is set to P2P. The default
224 is 0 (disabled).
225 inhibit_multicast_service
227 Some unicast mode profiles insist that no multicast message are
228 ever transmitted. Setting this option inhibits multicast trans‐
229 mission. The default is 0 (mutlicast enabled).
230 net_sync_monitor
232 Enables the NetSync Monitor (NSM) protocol. The NSM protocol
233 allows a station to measure how well another node is synchro‐
234 nized. The monitor sends a unicast delay request to the node,
235 which replies unconditionally with unicast delay response, sync,
236 and follow up messages. If the monitor is synchronized to the
237 GM, it can use the time stamps in the message to estimate the
238 node's offset. This option requires that the 'hybrid_e2e'
239 option be enabled as well. The default is 0 (disabled).
240 unicast_listen
242 When enabled, this option allows the port to grant unicast mes‐
243 sage contracts. Incoming requests for will be granted limited
244 only by the amount of memory available. The default is 0 (dis‐
245 abled).
246 unicast_master_table
248 When set to a positive integer, this option specifies the table
249 id to be used for unicast discovery. Each table lives in its
250 own section and has a unique, positive numerical ID. Entries in
251 the table are a pair of transport type and protocol address.
252 Tables may not be shared between ports, but nothing prevents ta‐
253 ble entries from appearing in more than table. The default is 0
254 (unicast discovery disabled).
255 unicast_req_duration
257 The service time in seconds to be requested during unicast dis‐
258 covery. Note that the remote node is free to grant a different
259 duration. The default is 3600 seconds or one hour.
260 ptp_dst_mac
262 The MAC address to which PTP messages should be sent. Relevant
263 only with L2 transport. The default is 01:1B:19:00:00:00.
264 p2p_dst_mac
266 The MAC address to which peer delay messages should be sent.
267 Relevant only with L2 transport. The default is
268 01:80:C2:00:00:0E.
269 network_transport
271 Select the network transport. Possible values are UDPv4, UDPv6
272 and L2. The default is UDPv4.
273 neighborPropDelayThresh
275 Upper limit for peer delay in nanoseconds. If the estimated peer
276 delay is greater than this value the port is marked as not
277 802.1AS capable.
278 masterOnly
280 Setting this option to one (1) prevents the port from entering
281 the SLAVE state. In addition, the local clock will ignore
282 Announce messages received on this port. This option's intended
283 use is to support the Telecom Profiles according to ITU-T
284 G.8265.1, G.8275.1, and G.8275.2. The default value is zero or
285 false.
286 G.8275.portDS.localPriority
288 The Telecom Profiles (ITU-T G.8275.1 and G.8275.2) specify an
289 alternate Best Master Clock Algorithm (BMCA) with a unique data
290 set comparison algorithm. The value of this option is associ‐
291 ated with Announce messages arriving on a particular port and is
292 used as a tie breaker whenever clockClass, clockAccuracy, off‐
293 setScaledLogVariance, and priority2 are equal. This option is
294 only used when "dataset_comparison" is set to "telecom". The
295 default value is 128.
296 Warning: the BMCA is guaranteed to produce a spanning tree (that
298 is, a timing network without loops) only when using the default
299 values of G.8275.defaultDS.localPriority and
300 G.8275.portDS.localPriority. Careful network engineering is
301 needed when using non-default values.
302 min_neighbor_prop_delay
304 Lower limit for peer delay in nanoseconds. If the estimated peer
305 delay is smaller than this value the port is marked as not
306 802.1AS capable.
307 tsproc_mode
309 Select the time stamp processing mode used to calculate offset
310 and delay. Possible values are filter, raw, filter_weight,
311 raw_weight. Raw modes perform well when the rate of sync mes‐
312 sages (logSyncInterval) is similar to the rate of delay messages
313 (logMinDelayReqInterval or logMinPdelayReqInterval). Weighting
314 is useful with larger network jitters (e.g. software time stamp‐
315 ing). The default is filter.
316 delay_filter
318 Select the algorithm used to filter the measured delay and peer
319 delay. Possible values are moving_average and moving_median.
320 The default is moving_median.
321 delay_filter_length
323 The length of the delay filter in samples. The default is 10.
324 egressLatency
326 Specifies the difference in nanoseconds between the actual
327 transmission time at the reference plane and the reported trans‐
328 mit time stamp. This value will be added to egress time stamps
329 obtained from the hardware. The default is 0.
330 ingressLatency
332 Specifies the difference in nanoseconds between the reported
333 receive time stamp and the actual reception time at reference
334 plane. This value will be subtracted from ingress time stamps
335 obtained from the hardware. The default is 0.
336 boundary_clock_jbod
338 When running as a boundary clock (that is, when more than one
339 network interface is configured), ptp4l performs a sanity check
340 to make sure that all of the ports share the same hardware clock
341 device. This option allows ptp4l to work as a boundary clock
342 using "just a bunch of devices" that are not synchronized to
343 each other. For this mode, the collection of clocks must be syn‐
344 chronized by an external program, for example phc2sys(8) in
345 "automatic" mode. The default is 0 (disabled).
346 udp_ttl
348 Specifies the Time to live (TTL) value for IPv4 multicast mes‐
349 sages and the hop limit for IPv6 multicast messages. This option
350 is only relevant with the IPv4 and IPv6 UDP transports. The
351 default is 1 to restrict the messages sent by ptp4l to the same
352 subnet.
353
356 twoStepFlag
357 Enable two-step mode for sync messages. One-step mode can be
358 used only with hardware time stamping. The default is 1
359 (enabled).
360 slaveOnly
362 The local clock is a slave-only clock if enabled. The default is
363 0 (disabled).
364 socket_priority
366 Configure the SO_PRIORITY of sockets. This is to support cases
367 where a user wants to route ptp4l traffic using Linux qdiscs for
368 the purpose of traffic shaping. This option is only available
369 with the IEEE 802.3 transport (the -2 option) and is silently
370 ignored when using the UDP IPv4/6 network transports. Must be in
371 the range of 0 to 15, inclusive. The default is 0.
372 gmCapable
374 If this option is enabled, then the local clock is able to
375 become grand master. This is only for use with 802.1AS clocks
376 and has no effect on 1588 clocks. The default is 1 (enabled).
377 priority1
379 The priority1 attribute of the local clock. It is used in the
380 best master selection algorithm, lower values take precedence.
381 Must be in the range 0 to 255. The default is 128.
382 priority2
384 The priority2 attribute of the local clock. It is used in the
385 best master selection algorithm, lower values take precedence.
386 Must be in the range 0 to 255. The default is 128.
387 clockClass
389 The clockClass attribute of the local clock. It denotes the
390 traceability of the time distributed by the grandmaster clock.
391 The default is 248.
392 clockAccuracy
394 The clockAccuracy attribute of the local clock. It is used in
395 the best master selection algorithm. The default is 0xFE.
396 clockIdentity
398 The clockIdentity attribute of the local clock. The clockIden‐
399 tity is an 8-octet array and should in this configuration be
400 written in textual form, see default. It should be unique since
401 it is used to identify the specific clock. If default is used
402 or if not set at all, the clockIdentity will be automtically
403 generated. The default is "000000.0000.000000"
404 offsetScaledLogVariance
406 The offsetScaledLogVariance attribute of the local clock. It
407 characterizes the stability of the clock. The default is
408 0xFFFF.
409 G.8275.defaultDS.localPriority
411 The Telecom Profiles (ITU-T G.8275.1 and G.8275.2) specify an
412 alternate Best Master Clock Algorithm (BMCA) with a unique data
413 set comparison algorithm. The value of this option is associ‐
414 ated with the local clock and is used as a tie breaker whenever
415 clockClass, clockAccuracy, offsetScaledLogVariance, and prior‐
416 ity2 are equal. This option is only used when "dataset_compari‐
417 son" is set to "telecom". The default value is 128.
418 Warning: the BMCA is guaranteed to produce a spanning tree (that
420 is, a timing network without loops) only when using the default
421 values of G.8275.defaultDS.localPriority and
422 G.8275.portDS.localPriority. Careful network engineering is
423 needed when using non-default values.
424 maxStepsRemoved
426 When using this option, if the value of stepsRemoved of an
427 Announce message is greater than or equal to the value of
428 maxStepsRemoved the Announce message is not considered in the
429 operation of the BMCA. The default value is 255.
430 domainNumber
433 The domain attribute of the local clock. The default is 0.
434 utc_offset
436 The current offset between TAI and UTC. The default is 37.
437 free_running
439 Don't adjust the local clock if enabled. The default is 0 (dis‐
440 abled).
441 freq_est_interval
443 The time interval over which is estimated the ratio of the local
444 and peer clock frequencies. It is specified as a power of two in
445 seconds. The default is 1 (2 seconds).
446 assume_two_step
448 Treat one-step responses as two-step if enabled. It is used to
449 work around buggy 802.1AS switches. The default is 0 (dis‐
450 abled).
451 tc_spanning_tree
453 When running as a Transparent Clock, increment the "stepsRe‐
454 moved" field of Announce messages that pass through the switch.
455 Enabling this option ensures that PTP message loops never form,
456 provided the switches all implement this option together with
457 the BMCA.
458 tx_timestamp_timeout
460 The number of milliseconds to poll waiting for the tx time stamp
461 from the kernel when a message has recently been sent. The
462 default is 1.
463 check_fup_sync
465 Because of packet reordering that can occur in the network, in
466 the hardware, or in the networking stack, a follow up message
467 can appear to arrive in the application before the matching sync
468 message. As this is a normal occurrence, and the sequenceID mes‐
469 sage field ensures proper matching, the ptp4l program accepts
470 out of order packets. This option adds an additional check using
471 the software time stamps from the networking stack to verify
472 that the sync message did arrive first. This option is only use‐
473 ful if you do not trust the sequence IDs generated by the mas‐
474 ter. The default is 0 (disabled).
475 clock_servo
477 The servo which is used to synchronize the local clock. Valid
478 values are "pi" for a PI controller, "linreg" for an adaptive
479 controller using linear regression, "ntpshm" for the NTP SHM
480 reference clock to allow another process to synchronize the
481 local clock (the SHM segment number is set to the domain num‐
482 ber), and "nullf" for a servo that always dials frequency offset
483 zero (for use in SyncE nodes). The default is "pi."
484 clock_type
486 Specifies the kind of PTP clock. Valid values are "OC" for
487 ordinary clock, "BC" for boundary clock, "P2P_TC" for peer to
488 peer transparent clock, and "E2E_TC" for end to end transparent
489 clock. An multi-port ordinary clock will automatically be con‐
490 figured as a boundary clock. The default is "OC".
491 pi_proportional_const
493 The proportional constant of the PI controller. When set to 0.0,
494 the proportional constant will be set by the following formula
495 from the current sync interval. The default is 0.0.
496 kp = min(kp_scale * sync^kp_exponent, kp_norm_max / sync)
498 pi_integral_const
500 The integral constant of the PI controller. When set to 0.0, the
501 integral constant will be set by the following formula from the
502 current sync interval. The default is 0.0.
503 ki = min(ki_scale * sync^ki_exponent, ki_norm_max / sync)
505 pi_proportional_scale
507 The kp_scale constant in the formula used to set the propor‐
508 tional constant of the PI controller from the sync interval.
509 When set to 0.0, the value will be selected from 0.7 and 0.1 for
510 the hardware and software time stamping respectively. The
511 default is 0.0.
512 pi_proportional_exponent
514 The kp_exponent constant in the formula used to set the propor‐
515 tional constant of the PI controller from the sync interval.
516 The default is -0.3.
517 pi_proportional_norm_max
519 The kp_norm_max constant in the formula used to set the propor‐
520 tional constant of the PI controller from the sync interval.
521 The default is 0.7
522 pi_integral_scale
524 The ki_scale constant in the formula used to set the integral
525 constant of the PI controller from the sync interval. When set
526 to 0.0, the value will be selected from 0.3 and 0.001 for the
527 hardware and software time stamping respectively. The default
528 is 0.0.
529 pi_integral_exponent
531 The ki_exponent constant in the formula used to set the integral
532 constant of the PI controller from the sync interval. The
533 default is 0.4.
534 pi_integral_norm_max
536 The ki_norm_max constant in the formula used to set the integral
537 constant of the PI controller from the sync interval. The
538 default is 0.3.
539 step_threshold
541 The maximum offset the servo will correct by changing the clock
542 frequency instead of stepping the clock. When set to 0.0, the
543 servo will never step the clock except on start. It's specified
544 in seconds. The default is 0.0. This option used to be called
545 pi_offset_const.
546 first_step_threshold
548 The maximum offset the servo will correct by changing the clock
549 frequency instead of stepping the clock. This is only applied on
550 the first update. It's specified in seconds. When set to 0.0,
551 the servo won't step the clock on start. The default is 0.00002
552 (20 microseconds). This option used to be called pi_f_off‐
553 set_const.
554 max_frequency
556 The maximum allowed frequency adjustment of the clock in parts
557 per billion (ppb). This is an additional limit to the maximum
558 allowed by the hardware. When set to 0, the hardware limit will
559 be used. The default is 900000000 (90%). This option used to
560 be called pi_max_frequency.
561 sanity_freq_limit
563 The maximum allowed frequency offset between uncorrected clock
564 and the system monotonic clock in parts per billion (ppb). This
565 is used as a sanity check of the synchronized clock. When a
566 larger offset is measured, a warning message will be printed and
567 the servo will be reset. When set to 0, the sanity check is dis‐
568 abled. The default is 200000000 (20%).
569 initial_delay
571 The initial path delay of the clock in nanoseconds used for syn‐
572 chronization of the clock before the delay is measured using the
573 E2E or P2P delay mechanism. If set to 0, the clock will not be
574 updated until the delay is measured. The default is 0.
575 ntpshm_segment
577 The number of the SHM segment used by ntpshm servo. The default
578 is 0.
579 udp6_scope
581 Specifies the desired scope for the IPv6 multicast messages.
582 This will be used as the second byte of the primary address.
583 This option is only relevant with IPv6 transport. See RFC 4291.
584 The default is 0x0E for the global scope.
585 uds_address
587 Specifies the address of the UNIX domain socket for receiving
588 local management messages. The default is /var/run/ptp4l.
589 dscp_event
591 Defines the Differentiated Services Codepoint (DSCP) to be used
592 for PTP event messages. Must be a value between 0 and 63. There
593 are several media streaming standards out there that require
594 specific values for this option. For example 46 (EF PHB) in
595 AES67 or 48 (CS6 PHB) in RAVENNA. The default is 0.
596 dscp_general
598 Defines the Differentiated Services Codepoint (DSCP) to be used
599 for PTP general messages. Must be a value between 0 and 63.
600 There are several media streaming standards out there that rec‐
601 ommend specific values for this option. For example 34 (AF41
602 PHB) in AES67 or 46 (EF PHB) in RAVENNA. The default is 0.
603 dataset_comparison
605 Specifies the method to be used when comparing data sets during
606 the Best Master Clock Algorithm. The possible values are
607 "ieee1588" and "G.8275.x". The default is "ieee1588".
608 logging_level
610 The maximum logging level of messages which should be printed.
611 The default is 6 (LOG_INFO).
612 message_tag
614 The tag which is added to all messages printed to the standard
615 output or system log. The default is an empty string (which
616 cannot be set in the configuration file as the option requires
617 an argument).
618 verbose
620 Print messages to the standard output if enabled. The default
621 is 0 (disabled).
622 use_syslog
624 Print messages to the system log if enabled. The default is 1
625 (enabled).
626 summary_interval
628 The time interval in which are printed summary statistics of the
629 clock. It is specified as a power of two in seconds. The statis‐
630 tics include offset root mean square (RMS), maximum absolute
631 offset, frequency offset mean and standard deviation, and path
632 delay mean and standard deviation. The units are nanoseconds and
633 parts per billion (ppb). If there is only one clock update in
634 the interval, the sample will be printed instead of the statis‐
635 tics. The messages are printed at the LOG_INFO level. The
636 default is 0 (1 second).
637 time_stamping
639 The time stamping method. The allowed values are hardware, soft‐
640 ware and legacy. The default is hardware.
641 productDescription
643 The product description string. Allowed values must be of the
644 form manufacturerName;modelNumber;instanceIdentifier and contain
645 at most 64 utf8 symbols. The default is ";;".
646 revisionData
648 The revision description string which contains the revisions for
649 node hardware (HW), firmware (FW), and software (SW). Allowed
650 values are of the form HW;FW;SW and contain at most 32 utf8 sym‐
651 bols. The default is an ";;".
652 userDescription
654 The user description string. Allowed values are of the form
655 name;location and contain at most 128 utf8 symbols. The default
656 is an empty string.
657 manufacturerIdentity
659 The manufacturer id which should be an OUI owned by the manufac‐
660 turer. The default is 00:00:00.
661 kernel_leap
663 When a leap second is announced, let the kernel apply it by
664 stepping the clock instead of correcting the one-second offset
665 with servo, which would correct the one-second offset slowly by
666 changing the clock frequency (unless the step_threshold option
667 is set to correct such offset by stepping). Relevant only with
668 software time stamping. The default is 1 (enabled).
669 timeSource
671 The time source is a single byte code that gives an idea of the
672 kind of local clock in use. The value is purely informational,
673 having no effect on the outcome of the Best Master Clock algo‐
674 rithm, and is advertised when the clock becomes grand master.
675 hwts_filter
677 Select the hardware time stamp filter setting mode. Possible
678 values are normal, check, full. Normal mode set the filters as
679 needed. Check mode only check but do not set. Full mode set
680 the receive filter to mark all packets with hardware time stamp,
681 so all applications can get them. The default is normal.
682 asCapable
684 If set to 'true', all the checks which can unset asCapable vari‐
685 able (as described in Section 10.2.4.1 of 802.1AS) are skipped.
686 If set to 'auto', asCapable is initialized to 'false' and will
687 be set to 'true' after the relevant checks have passed. The
688 default value is 'auto'.
689 BMCA This option enables use of static roles for master and slave
691 devices instead of running the best master clock algorithm
692 (BMCA) described in 1588 profile. This is useful when you know
693 the roles of the devices in advance. When set to ´noop', the
694 traditional BMCA algorithm used by 1588 is skipped. masterOnly
695 and slaveOnly will be used to determine master or slave role for
696 the device. In a bridge, slaveOnly (which is a global option)
697 can be set to make all ports assume the slave role. masterOnly
698 (which is a per-port config option) can then be used to set
699 individual ports to take master role. BMCA is used in the Auto‐
700 motive profile to speed up the start time for grand master and
701 slaves. The default value is 'ptp' which runs the BMCA related
702 state machines.
703 inhibit_announce
705 This will disable the timer for announce messages (i.e.
706 FD_MANNO_TIMER) and also the announce message timeout timer
707 (i.e. FD_ANNOUNCE_TIMER). This is used by the Automotive profile
708 as part of switching over to a static BMCA. if this option is
709 enabled, ignore_source_id has to be enabled in the slave because
710 it has no way to identify master identity in Sync and Follow_Up
711 messages. The default is 0 (disabled).
712 ignore_source_id
714 This will disable source port identity checking for Sync and
715 Follow_Up messages. This is useful when the announce messages
716 are disabled in the master and the slave does not have any way
717 to know it's identity. The default is 0 (disabled).
718 servo_num_offset_values
720 The number of offset values calculated in previously received
721 Sync messages to consider when adjusting the Sync and Pdelay
722 request intervals. More information provided in the description
723 of 'offset_threshold'. The default value is 10.
724 servo_offset_threshold
726 This value is used by the slave for adjusting the intervals for
727 Sync and Pdelay request messages. The slave will check the last
728 'num_offset_values' offsets and if all those offsets are less
729 than the offset_threshold, it will adjust both the intervals.
730 The Sync interval is adjusted via the signaling mechanism and
731 the pdelay request interval is just adjusted locally. The new
732 values to use for sync message intervals and pdelay request
733 intervals can be indicated by operLogSyncInterval and operLog‐
734 PdelayReqInterval respectively. This mechanism is currently only
735 supported when BMCA == 'noop'. The default value of off‐
736 set_threshold is 0 (disabled).
737
740 table_id
741 Each table must begin with a unique, positive table ID. The
742 port that claims a given table does so by including the ID as
743 the value of its 'unicast_master_table' option.
744 logQueryInterval
746 This option configures the time to wait between unicast negotia‐
747 tion attempts. It is specified as a power of two in seconds.
748 The default is 0 (1 second).
749 peer_address
751 This option specifies the unicast address of the peer for use
752 with the peer to peer delay mechanism. If specified, the port
753 owning the table will negotiate unicast peer delay responses
754 from the machine at the given remote address, otherwise the port
755 will send multicast peer delay requests.
756 L2|UDPv4|UDPv6
758 Each table entry specifies the transport type and network
759 address of a potential remote master. If multiple masters are
760 specified, then unicast negotiation will be performed with each
761 if them.
762
765 ptp4l as domain master either uses PTP or UTC time scale depending on
766 time stamping mode. In software and legacy time stamping modes it
767 announces Arbitrary time scale mode, which is effectively UTC here, in
768 hardware time stamping mode it announces use of PTP time scale.
769 When ptp4l is the domain master using hardware time stamping, it is up
771 to phc2sys to maintain the correct offset between UTC and PTP times.
772 See phc2sys(8) manual page for more details.
773
776 pmc(8), phc2sys(8)
777linuxptp April 2018 PTP4l(8)