Subject: [TICTOC] Some comments post draft-alavarez-hamelin-tictoc-sic-00 presentation

From: J Ignacio Alvarez-Hamelin <[email-masked]>
Date: Wed, 28 Mar 2018 19:05:06 -0300

Dear all,

A wise question arises about "why not use NTP directly if can find one at four hops maximum?” I was answered (off-mic) that in Latin-America (and other places like Africa as an example), the network is not so good. I provide here a case in Argentina, trying to reach an NTP server from 4 different points at the Buenos Aires city. 

As you will appreciate, the distances of each trace are entirely different times; also and take a special look at the STD, average and maximum: you will see huge variations. I also repeated the experiment with fewer samples, and again the numbers are entirely different (i.e., the traffic introduces a lot of noise). 
When we developed SIC the objective was to compute one-way-measurements en any place of the Internet; and as these measurements are related with the dynamics of the latency, frequency synchronization is enough when MTIE is 20 microsecond by a minute. 

The delays are here:

host1$ mtr -r -c 100 time.afip.gov.ar
Start: Tue Mar 27 19:03:51 2018
HOST: raspbian-server             Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- gw-vlan-srv.innova-red.ne  0.0%   100    2.2   2.8   2.1  37.7   4.9
  2.|-- rnoc5.BUENOS-AIRES.innova  0.0%   100    2.3   3.8   2.1  55.8   7.9                                                    
  3.|-- 10.5.10.2                  0.0%   100    2.5   2.6   2.2   3.1   0.0                                                    
  4.|-- 200.0.17.104               0.0%   100    3.1   3.1   2.4  13.7   1.1                                                    
  5.|-- 172.18.2.53                0.0%   100    4.8   5.7   3.8  12.4   1.7
  6.|-- time.afip.gob.ar           0.0%   100    5.2   5.2   3.8  12.0   1.3

host2$ mtr -r -c 100 time.afip.gov.ar
Start: Tue Mar 27 19:03:47 2018
HOST: ws-david                    Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.10.96.1                 0.0%   100    0.3   0.2   0.2   0.3   0.0
  2.|-- 200.16.116.171             0.0%   100    1.0   5.9   0.6 158.4  22.9
  3.|-- static.33.229.104.190.cps  1.0%   100    1.6   2.5   1.5  80.6   8.0
  4.|-- static.129.192.104.190.cp  0.0%   100    2.1   1.9   1.8   3.0   0.1
  5.|-- 200.0.17.104               1.0%   100    2.0   2.2   1.8   9.4   0.7
  6.|-- 172.18.2.53                0.0%   100    3.2   4.2   3.1  12.0   1.5
  7.|-- auth.afip.gob.ar           0.0%   100    4.2   4.5   3.3   9.8   1.2

host3$ mtr -r -c 100 time.afip.gov.ar
Start: 2018-03-27T19:03:51-0300
HOST: aleph.local                 Loss%   Snt   Last   Avg  Best  Wrst StDev
 1.|-- 10.17.71.254               0.0%   100    4.7  30.3   3.5 280.4  52.4
 2.|-- 10.255.254.250             0.0%   100    2.5  31.1   1.8 285.4  59.2
 3.|-- 209.13.133.10              0.0%   100   30.5  43.9   2.3 237.2  64.9
 4.|-- host169.advance.com.ar     3.0%   100   36.0  64.8   3.1 404.4  86.9
 5.|-- 200.32.33.33               2.0%   100  106.9  70.6   2.8 315.0  80.4
 6.|-- 200.32.34.66               5.0%   100   93.1  56.8   2.7 336.1  74.5
 7.|-- 200.32.33.38               7.0%   100   42.8  58.0   2.9 357.8  76.7
 8.|-- 209.13.139.211             4.0%   100   46.2  56.7   2.8 298.8  69.9
 9.|-- 209.13.139.209             1.0%   100   84.5  57.1   2.6 277.7  72.3
10.|-- 209.13.166.211             1.0%   100   43.4  63.5   3.2 390.6  78.7
11.|-- 200.32.34.137              2.0%   100   68.7  64.1   3.7 259.5  75.5
12.|-- 200.32.33.37               0.0%   100    4.1  56.9   3.3 249.6  64.3
13.|-- 200.32.34.121              3.0%   100   10.9  65.0   4.1 415.7  85.1
14.|-- 200.32.33.241              2.0%   100  252.6  61.8   3.8 355.9  74.5
15.|-- 200.16.206.198             3.0%   100  188.0  54.6   3.1 461.7  74.9
16.|-- 172.18.2.53                2.0%   100  133.4  53.1   4.3 402.1  69.2
17.|-- time.afip.gob.ar           4.0%   100   72.5  54.1   4.9 343.2  66.9

host4$ mtr -r -c 100 time.afip.gov.ar
Start: 2018-03-27T19:03:51-0300
HOST: cnet                        Loss%   Snt   Last   Avg  Best  Wrst StDev
 1.|-- 157.92.58.1                0.0%   100    6.6   2.8   0.3  12.8   2.5
 2.|-- ???                       100.0   100    0.0   0.0   0.0   0.0   0.0
 3.|-- ???                       100.0   100    0.0   0.0   0.0   0.0   0.0
 4.|-- host98.131-100-186.static  0.0%   100    5.7   5.6   1.5   9.4   2.2
 5.|-- host130.131-100-186.stati  0.0%   100    6.5   6.3   2.5  10.3   2.2
 6.|-- 200.0.17.104               0.0%   100    2.4   2.7   2.3  15.6   1.4
 7.|-- ???                       100.0   100    0.0   0.0   0.0   0.0   0.0
 8.|-- time.afip.gob.ar           0.0%   100    4.9   7.6   3.9 243.0  23.9

————————————————————————————————————————————

host1$ mtr -r -c 100 time.afip.gov.ar 
Start: Tue Mar 27 18:57:06 2018
HOST: raspbian-server             Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- gw-vlan-srv.innova-red.ne  0.0%    50    2.4   2.8   2.0  34.2   4.5
  2.|-- rnoc5.BUENOS-AIRES.innova  0.0%    50    2.1   3.8   2.1  52.8   7.7
  3.|-- 10.5.10.2                  0.0%    50    2.7   2.9   2.2  15.6   1.8
  4.|-- 200.0.17.104               0.0%    50    2.8   3.0   2.3   3.9   0.0
  5.|-- 172.18.2.53                0.0%    50    4.5   5.8   3.8  17.8   2.2
  6.|-- time.afip.gob.ar           0.0%    50    4.7   9.9   4.2 238.5  33.0

host2$ mtr -r -c 100 time.afip.gov.ar
Start: Tue Mar 27 18:57:00 2018
HOST: ws-david                    Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.10.96.1                 0.0%    50    0.3   0.3   0.2   0.7   0.0
  2.|-- 200.16.116.171             0.0%    50    0.9   6.7   0.7 196.5  29.1
  3.|-- static.33.229.104.190.cps  2.0%    50    1.6   1.7   1.5   2.2   0.0
  4.|-- static.129.192.104.190.cp  0.0%    50    2.1   2.0   1.7   2.4   0.0
  5.|-- 200.0.17.104               0.0%    50    2.0   2.1   1.8   2.6   0.0
  6.|-- 172.18.2.53                0.0%    50    4.8   4.3   3.2   9.1   1.3
  7.|-- time.afip.gob.ar           0.0%    50    4.3   9.4   3.3 234.9  32.7

host3$ mtr -r -c 100 time.afip.gov.ar
Start: 2018-03-27T18:57:05-0300
HOST: aleph.local                 Loss%   Snt   Last   Avg  Best  Wrst StDev
 1.|-- 10.17.71.254               0.0%    50  125.6  88.1   3.7 392.4  79.3
 2.|-- 10.255.254.250             0.0%    50   62.1  54.8   2.1 333.2  68.0
 3.|-- 209.13.133.10              0.0%    50    4.0  33.9   2.4 280.8  51.3
 4.|-- host169.advance.com.ar     2.0%    50    4.1  21.3   2.9 236.7  40.4
 5.|-- 200.32.33.33               2.0%    50    4.5  32.2   3.2 341.3  69.4
 6.|-- 200.32.34.66               4.0%    50    7.7  26.0   3.5 278.8  55.8
 7.|-- 200.32.33.38               2.0%    50    4.8  29.4   3.0 221.3  43.4
 8.|-- 209.13.139.211             0.0%    50   84.8  40.3   3.1 250.4  53.0
 9.|-- 209.13.139.209             0.0%    50   25.1  35.0   2.8 249.2  55.4
10.|-- 209.13.166.211             0.0%    50    3.7  33.5   2.6 188.9  54.3
11.|-- 200.32.34.137              0.0%    50    5.6  28.2   3.7 224.3  51.1
12.|-- 200.32.33.37               0.0%    50    3.7  24.2   3.5 189.5  44.9
13.|-- 200.32.34.121              0.0%    50    4.7  30.8   4.0 213.2  51.6
14.|-- 200.32.33.241              0.0%    50   14.4  33.1   3.9 364.6  67.2
15.|-- 200.16.206.198             0.0%    50    5.0  58.2   3.1 300.7  88.5
16.|-- 172.18.2.53                0.0%    50    9.4 117.8   4.4 315.1 103.4
17.|-- time.afip.gob.ar           0.0%    50  199.6 120.2   5.2 484.0  96.2

host4$ mtr -r -c 100 time.afip.gov.ar
Start: Tue Mar 27 18:41:40 2018
HOST: cnet                        Loss%   Snt   Last   Avg  Best  Wrst StDev
 1.|-- 157.92.58.1                0.0%    50    4.0   1.6   0.3   9.1   1.6
 2.|-- ???                       100.0    50    0.0   0.0   0.0   0.0   0.0
 3.|-- ???                       100.0    50    0.0   0.0   0.0   0.0   0.0
 4.|-- host98.131-100-186.static  0.0%    50    4.7   5.5   1.5  10.9   2.4
 5.|-- host130.131-100-186.stati  0.0%    50    8.4   6.5   2.6  10.5   2.2
 6.|-- 200.0.17.104               0.0%    50    2.5   2.8   2.3  11.0   1.2
 7.|-- ???                       100.0    50    0.0   0.0   0.0   0.0   0.0
 8.|-- time.afip.gob.ar           0.0%    50    4.9   9.2   3.8 226.7  31.4

Best,

	J. Ignacio

_______________________________________________________________

Dr. Ing. José Ignacio Alvarez-Hamelin
CONICET and Facultad de Ingeniería, Universidad de Buenos Aires
Av. Paseo Colón 850 - C1063ACV - Buenos Aires - Argentina
+54 (11) 5285 0716 / 5285 0705
e-mail: [email-masked]
web: http://cnet.fi.uba.ar/ignacio.alvarez-hamelin/
_______________________________________________________________