CONDUIT latencies (fwd)

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================

---------- Forwarded message ----------
Date: Fri, 16 Jul 1999 12:49:25 GMT
From: "David J. Knight" <address@hidden>
To: address@hidden, address@hidden
Subject: CONDUIT latencies

Hi,
     We've being receiving the CONDUIT/NMC2 data feed
at UAlbany for some time now. Unfortunately it has not proven
to be particularly reliable. Specifically, there are
many hours of the day when latencies get to 3600 sec
and we start losing data. Right now the nmc2 feed is
of little value to us, so we have to continue to
ftp the files from the oso server.

     I wonder if other NMC2 sites are seeing *very*
inconsistant receipt of data? If not, then it is 
probably a local problem, so you don't need to read
further unless you are willing to serve us the feed ;)

We currently obtain the feed from flood.atmos.uiuc.edu
Here are entries from last 24 hours of stat files:

1999071512.stats:19990715125444    NMC2                       tgsv7a       8430 
 121583537    1658.38 3660@5442 19990715135542
1999071513.stats:19990715134129    NMC2                       tgsv7a         11 
      1225    3053.57 3640@2725 19990715143959
1999071514.stats:19990715145703    NMC2                       tgsv7a       4303 
 105105886    3256.68 3661@3443 19990715155125
1999071515.stats:19990715155934    NMC2                       tgsv7a       1483 
  32642622    3224.65 3660@1245 19990715162745
1999071516.stats:19990715165234    NMC2                       tgsv7a         85 
      9179    2657.02 3560@4717 19990715174638
1999071518.stats:19990715184725    NMC2                       tgsv7a         15 
      1675     163.28  516@0710 19990715184845
1999071519.stats:19990715195817    NMC2                       tgsv7a       4484 
 109037162    1405.73 3656@5814 19990715205910
1999071520.stats:19990715203610    NMC2                       tgsv7a       3645 
  60369581    3017.24 3660@0115 19990715213615
1999071521.stats:19990715215229    NMC2                       tgsv7a         21 
      2345     465.78 1006@5221 19990715220907
1999071522.stats:19990715224341    NMC2                       tgsv7a         12 
      1340     406.33  923@4327 19990715225849
1999071523.stats:19990715234338    NMC2                       tgsv7a         12 
      1340     340.78  876@4326 19990715235802
1999071600.stats:19990716003757    NMC2                       tgsv7a          3 
       335     134.08  271@3757 19990716004227
1999071601.stats:19990716015253    NMC2                       tgsv7a         33 
      3685    1091.47 2428@5233 19990716023301
1999071602.stats:19990716025911    NMC2                       tgsv7a       2453 
  59397579    2824.92 3660@2035 19990716040007
1999071603.stats:19990716035113    NMC2                       tgsv7a        800 
  18925585    3577.05 3660@0206 19990716045200
1999071604.stats:19990716045539    NMC2                       tgsv7a          8 
       892    3210.54 3545@5539 19990716055445
1999071605.stats:19990716054700    NMC2                       tgsv7a         12 
      1340    1517.95 2727@4651 19990716063217
1999071606.stats:19990716064901    NMC2                       tgsv7a       3080 
  74064891    2620.21 3660@2430 19990716074938
1999071607.stats:19990716075937    NMC2                       tgsv7a       1932 
 120454025    3094.27 3661@5311 19990716090037
1999071608.stats:19990716083903    NMC2                       tgsv7a       2320 
  46350502    3575.35 3661@0515 19990716093802
1999071609.stats:19990716095420    NMC2                       tgsv7a         19 
      2120    1531.36 3359@5420 19990716105019
1999071610.stats:19990716104532    NMC2                       tgsv7a         11 
      1228    2111.46 3260@4532 19990716113952
1999071611.stats:19990716114554    NMC2                       tgsv7a          9 
      1003    1538.50 2273@4554 19990716122347

Looking at http://www.unidata.ucar.edu/staff/chiz/ncep_idd/gifs/latency_NMC.gif
it appears this is the worse possible place to obtain the feed from!


I wonder if would be possible to get the feed from some other site.
Perhaps PSU. traceroutes look good to there (at least right now).

traceroute ihlseng.ugems.psu.edu
traceroute to ihlseng.ugems.psu.edu (128.118.41.50), 30 hops max, 40 byte 
packets
 1  be102 (169.226.4.1)  2 ms  1 ms  1 ms
 2  169.226.13.1 (169.226.13.1)  1 ms  1 ms  1 ms
 3  at-gw3-alb-1-0-T3.appliedtheory.net (169.130.23.5)  2 ms  9 ms  2 ms
 4  at-gw2-alb-0-0.appliedtheory.net (169.130.20.2)  3 ms  3 ms  3 ms
 5  at-gw2-syr-1-1-0-T3.appliedtheory.net (169.130.1.22)  6 ms  4 ms  4 ms
 6  at-bb1-pen-5-0-0-T3.appliedtheory.net (169.130.1.121)  17 ms  18 ms  18 ms
 7  sl-bb11-pen-4-2.sprintlink.net (144.232.5.113)  18 ms  17 ms  17 ms
 8  sl-bb12-pen-10-0.sprintlink.net (144.232.5.158)  17 ms  16 ms  16 ms
 9  sl-bb10-rly-10-1.sprintlink.net (144.232.8.153)  17 ms  16 ms  17 ms
10  144.232.0.62 (144.232.0.62)  18 ms  18 ms  17 ms
11  sl-pittssup-1-0-0-T3.sprintlink.net (144.232.184.10)  28 ms  30 ms  26 ms
12  penn-state.psc.net (192.88.115.90)  30 ms  30 ms  30 ms
13  Willard1-Fddi5-0.gw.psu.edu (128.118.100.4)  29 ms  31 ms  30 ms
14  172.28.20.2 (172.28.20.2)  32 ms  31 ms  30 ms
15  ihlseng.ugems.psu.edu (128.118.41.50)  30 ms *  31 ms

Actually traceroutes to flood.atmos.uiuc.edu don't look too bad either
...
15  flood.atmos.uiuc.edu (128.174.80.47)  44 ms  58 ms  48 ms

But they get the data later than most sites, and by the time
it gets to us much of it gets dropped

Thanks for your consideration
David

David Knight
Department of Earth and Atmospheric Sciences   Tel: (518)-442-4204
SUNYA   ES-228                                 Fax: (518)-442-4494
Albany, NY  12222                              Email: address@hidden