除了是否合規(guī)之外，合規(guī)性測(cè)試還會(huì)研究 syn1588? PTP 協(xié)議棧的鎖定行為。總體鎖定時(shí)間可分成兩個(gè)區(qū)間。第一個(gè)區(qū)間從調(diào)用 PTP 協(xié)議棧開始，包括 PTP 協(xié)議棧在接受 PTP Grandmaster 作為時(shí)間源之前需要完成的初始報(bào)文處理。PTP 協(xié)議棧將處理一系列連續(xù) PTP 通知報(bào)文中包含的數(shù)據(jù)。時(shí)間跨度由 PTP 協(xié)議棧在接受 PTP Grandmaster 之前必須考慮的連續(xù)報(bào)文總數(shù)以及 PTP 協(xié)議棧的速率確定。這些參數(shù)可由用戶配置，大多數(shù) PTP 規(guī)范中的每個(gè)都定義了子范圍和默認(rèn)值。

第二個(gè)區(qū)間取決于 PTP 協(xié)議棧的初始同步算法以及底層硬件的功能。上文的同步算法部分介紹了 syn1588? PTP 協(xié)議棧中實(shí)現(xiàn)的設(shè)計(jì)。通過(guò)評(píng)估 PTP 協(xié)議棧日志文件中的數(shù)據(jù)，可以非常有效地測(cè)量第二個(gè)區(qū)間。下面的日志輸出中提供了典型啟動(dòng)過(guò)程的相應(yīng)部分。

日志輸出中的第一行指示 PTP 協(xié)議棧開始使用 PTP Grandmaster 時(shí)間信息的時(shí)間點(diǎn)。較大偏移 (-1646305347758870528ns) 會(huì)導(dǎo)致 PTP 協(xié)議棧異步設(shè)置由第 2 行的日志輸出 do epoch jump to … 指示的 PTP 硬件時(shí)鐘。

殘余偏移量（以 -10ms 為單位）顯示在隨后的行中。PTP 協(xié)議棧使用一系列下游 PTP 事件報(bào)文來(lái)計(jì)算頻率偏移。收集足夠的數(shù)據(jù)后，PTP 協(xié)議棧會(huì)同步調(diào)整頻率和偏移。最后一步，PTP 協(xié)議棧將啟用 PI 控制環(huán)路，這可從下面日志輸出的最后 5 行中看到。

在此測(cè)試中，分別使用日志輸出第一行和最后一行的系統(tǒng)時(shí)間戳來(lái)計(jì)算第二個(gè)區(qū)間的長(zhǎng)度。

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如果使用通知速率和超時(shí)的默認(rèn)值，則第一個(gè)區(qū)間的持續(xù)時(shí)間小于 1 秒。

12:01:53.57872 TimestampStats<meanTime=1996-02-01 06:31:16 ptp, pathDelay=577ns, offset=
   -1646305347758870528ns>
12:01:53.57875 do epoch jump to 2022-03-03 12:02:30 ptp
12:01:54.32878 do no adjust as filters are not ready
12:01:54.81291 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=596ns, offset=-10985308ns>
12:01:54.81294 change to CALIBRATE state
12:01:54.86872 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=591ns, offset=-10985333ns>
12:01:54.91748 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=590ns, offset=-10985367ns>
12:01:54.95272 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=570ns, offset=-10985410ns>
12:01:55.03707 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=586ns, offset=-10985460ns>
12:01:55.09210 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=580ns, offset=-10985494ns>
12:01:55.17129 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=588ns, offset=-10985541ns>
12:01:55.26151 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=575ns, offset=-10985619ns>
12:01:55.32995 do no adjust as filters are not ready
12:01:55.34612 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=591ns, offset=-10985666ns>
12:01:55.40650 TimestampStats<meanTime=2022-03-03 12:02:31 ptp, pathDelay=577ns, offset=-10985701ns>
12:01:55.46685 TimestampStats <meanTime=2022-03-03 12:02:31 ptp, pathDelay=578ns, offset=-10985745ns>
12:01:55.50951 TimestampStats <meanTime=2022-03-03 12:02:31 ptp, pathDelay=576ns, offset=-10985782ns>
12:01:55.60322 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=592ns, offset=-10985832ns>
12:01:55.64053 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=576ns, offset=-10985870ns>
12:01:55.77892 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=578ns, offset=-10985957ns>
12:01:55.83618 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=578ns, offset=-10985998ns>
12:01:55.89710 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=580ns, offset=-10986037ns>
12:01:55.94715 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=572ns, offset=-10986066ns>
12:01:56.02576 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=591ns, offset=-10986119ns>
12:01:56.11254 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=582ns, offset=-10986174ns>
12:01:56.16287 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=581ns, offset=-10986208ns>
12:01:56.22994 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=587ns, offset=-10986256ns>
12:01:56.30856 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=593ns, offset=-10986300ns>
12:01:56.32965 do no adjust as filters are not ready
12:01:56.36520 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=591ns, offset=-10986335ns>
12:01:56.42143 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=585ns, offset=-10986379ns>
12:01:56.46719 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=582ns, offset=-10986415ns>
12:01:56.56008 TimestampStats <meanTime=2022-03-03 12:02:32 ptp, pathDelay=588ns, offset=-10986468ns>
12:01:56.65093 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=579ns, offset=-10986542ns>
12:01:56.70391 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=573ns, offset=-10986581ns>
12:01:56.77593 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=585ns, offset=-10986615ns>
12:01:56.84436 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=583ns, offset=-10986664ns>
12:01:56.93805 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=588ns, offset=-10986722ns>
12:01:57.01258 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=570ns, offset=-10986790ns>
12:01:57.01261 adjust drift -6.65936e-07s/s
12:01:57.01264 Adjust rate by -665.936 ns/s (speeding up)
12:01:57.01269 compensate Offset -0.0109868s
12:01:57.01274 change to COLLECT_DATA state
12:01:57.09895 TimestampStats <meanTime=2022-03-03 12:02:33 ptp, pathDelay=577ns, offset=-10ns>