rfc1128.ps

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

300 457 1911 17 (frequency, to synchronize time means to set the clocks so that all agree at a particular epoch wi)fjt
2211 457 39 0 (th)fjt
300 399 1950 14 (respect to UTC, as provided by national standards, and to synchronize clocks means to synchronize)fjt
greset -300 3599 2850 3599 2850 -301 -300 -301 np mto lto lto lto clip np
greset -75 3374 2624 3374 2624 2825 -75 2825 np mto lto lto lto clip np
/tface 4 def
4 encfont
colmap 1 [0 0 0 ] put
1 sci
/tszabs false def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
/trotate 0 def
/halign 0 def
/valign 0 def
/tunder false def
sf
300 2979 227 1 (RFC 1128)fjt
805 2979 941 5 (Performance of the Network Time Protocol)fjt
1948 2979 302 1 (October 1989)fjt
greset -300 3599 2850 3599 2850 -301 -300 -301 np mto lto lto lto clip np
greset -75 474 2624 474 2624 -75 -75 -75 np mto lto lto lto clip np
/tface 4 def
colmap 1 [0 0 0 ] put
1 sci
/tszabs false def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
/trotate 0 def
/halign 0 def
/valign 0 def
/tunder false def
sf
300 279 100 0 (Mills)fjt
2092 279 158 1 (Page 3)fjt
greset -300 3599 2850 3599 2850 -301 -300 -301 np mto lto lto lto clip np
%End page
showpage svobj restore gr
gs /svobj save def
%Begin page
UserSoP
greset -75 3374 2624 3374 2624 -75 -75 -75 np mto lto lto lto clip np
/tface 8 def
8 encfont
colmap 1 [0 0 0 ] put
1 sci
/tszabs false def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
/trotate 0 def
/halign 0 def
/valign 0 def
/tunder false def
sf
300 2335 1950 13 (them in both frequency and time. A clock synchronization subnet operates by measuring clock)fjt
300 2277 1771 15 (offsets between the various peers in the subnet and so is vulnerable to statistical delay vari)fjt
2071 2277 180 1 (ations on)fjt
300 2219 1950 14 (the various transmission paths between them. In the Internet the paths involved can have wide)fjt
300 2160 1773 13 (variations in delay and reliability, while the routing algorithms can select landline or satell)fjt
2073 2160 178 1 (ite paths,)fjt
300 2102 1574 11 (public network or dedicated links or even suspend service without prior notice.)fjt
300 2011 1776 9 (In statistically noisy subnets accurate time synchronization requires carefully engineered)fjt
2076 2011 174 1 ( filtering)fjt
300 1953 1876 13 (and selection algorithms and the use of redundant resources and diverse transmission paths, w)fjt
2176 1953 75 0 (hile)fjt
300 1895 1876 10 (accurate frequency synchronization requires finely tuned oscillator tracking loops and mult)fjt
2176 1895 75 0 (iple)fjt
300 1837 1881 14 (phase comparisons over relatively long periods of time. For instance, while only a few comparis)fjt
2181 1837 69 0 (ons)fjt
300 1778 1821 17 (are usually adequate to resolve local time for an Internet host to within a few tens of millise)fjt
2121 1778 129 0 (conds,)fjt
300 1720 1934 16 (dozens of measurements over many hours are required to resolve frequency to within a few tens o)fjt
2234 1720 17 0 (f)fjt
300 1662 424 2 (milliseconds per day.)fjt
300 1567 1830 17 (In NTP the roundtrip delay and clock offset relative to a peer time server are calculated as fo)fjt
2130 1567 120 0 (llows.)fjt
300 1509 1565 13 (Number the times of sending and receiving NTP messages as shown in Figure 1)fjt
1865 1509 152 3 ( and let )fjt
/tface 10 def
10 encfont
sf
2018 1509 14 0 (i)fjt
/tface 8 def
sf
2031 1509 219 3 ( be an even)fjt
300 1451 279 2 (integer. Then )fjt
/tface 10 def
sf
579 1451 14 0 (t)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
592 1446 12 0 (i)fjt
/tface 8 def
sf
604 1446 35 0 (-3)fjt
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
638 1451 25 1 (, )fjt
/tface 10 def
sf
664 1451 14 0 (t)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
677 1446 12 0 (i)fjt
/tface 8 def
sf
689 1446 35 0 (-2)fjt
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
723 1451 25 1 (, )fjt
/tface 10 def
sf
749 1451 14 0 (t)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
762 1446 12 0 (i)fjt
/tface 8 def
sf
774 1446 35 0 (-1)fjt
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
808 1451 98 2 ( and )fjt
/tface 10 def
sf
906 1451 14 0 (t)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
920 1446 12 0 (i)fjt
/tface 8 def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
931 1451 1319 12 ( are the contents of the four most recent timestamps as above. The)fjt
300 1392 318 2 (roundtrip delay )fjt
/tface 10 def
sf
618 1392 25 0 (d)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
643 1387 12 0 (i)fjt
/tface 8 def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
655 1392 343 4 ( and clock offset )fjt
/tface 10 def
sf
998 1392 22 0 (c)fjt
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
1020 1387 12 0 (i)fjt
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
1031 1392 13 1 ( )fjt
/tface 8 def
sf
1044 1392 1018 9 (of the receiving host relative to the sending peer is:)fjt
/tface 10 def
sf
(d)0 1 991 1298 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1016 1292 fet
/tface 8 def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
( )0 1 1028 1298 fet
/tface 12 def
/mpf false def
sf
(=)0 1 1040 1298 fet
/tface 8 def
/mpf true def
sf
( )0 1 1067 1298 fet
/tface 12 def
/mpf false def
sf
(\()0 1 1080 1298 fet
/tface 10 def
/mpf true def
sf
(t)0 1 1096 1298 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1110 1292 fet
/tface 8 def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
( )0 1 1122 1298 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1134 1298 fet
/tface 8 def
/mpf true def
sf
( )0 1 1161 1298 fet
/tface 10 def
sf
(t)0 1 1174 1298 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1188 1292 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1199 1292 fet
/tface 8 def
/mpf true def
sf
(3)0 1 1222 1292 fet
/tface 12 def
/mpf false def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
(\))0 1 1243 1298 fet
/tface 8 def
/mpf true def
sf
( )0 1 1259 1298 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1272 1298 fet
/tface 8 def
/mpf true def
sf
( )0 1 1299 1298 fet
/tface 12 def
/mpf false def
sf
(\()0 1 1311 1298 fet
/tface 10 def
/mpf true def
sf
(t)0 1 1328 1298 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1342 1292 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1353 1292 fet
/tface 8 def
/mpf true def
sf
(1)0 1 1376 1292 fet
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
( )0 1 1397 1298 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1409 1298 fet
/tface 8 def
/mpf true def
sf
( )0 1 1436 1298 fet
/tface 10 def
sf
(t)0 1 1449 1298 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1463 1292 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1474 1292 fet
/tface 8 def
/mpf true def
sf
(2)0 1 1497 1292 fet
/tface 12 def
/mpf false def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
(\))0 1 1518 1298 fet
/tface 8 def
/mpf true def
sf
1534 1298 25 1 ( ,)fjt
/tface 10 def
sf
(c)0 1 990 1202 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1012 1197 fet
/tface 8 def
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
( )0 1 1023 1202 fet
/tface 12 def
/mpf false def
sf
(=)0 1 1036 1202 fet
/tface 8 def
/mpf true def
sf
( )0 1 1063 1202 fet
/tface 12 def
/mpf false def
sf
(\()0 1 1078 1236 fet
/tface 10 def
/mpf true def
sf
(t)0 1 1095 1236 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1109 1231 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1120 1231 fet
/tface 8 def
/mpf true def
sf
(2)0 1 1143 1231 fet
/txscale 1200 3 mul 72 div def /tyscale 1200 3 mul 72 div def
sf
( )0 1 1164 1236 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1176 1236 fet
/tface 8 def
/mpf true def
sf
( )0 1 1203 1236 fet
/tface 10 def
sf
(t)0 1 1216 1236 fet
/txscale 1000 3 mul 72 div def /tyscale 1000 3 mul 72 div def
sf
(i)0 1 1230 1231 fet
/tface 12 def
/mpf false def
sf
(-)0 1 1241 1231 fet
/tface 8 def
/mpf true def