SoX has new routing in Abilene

Jiri Navratil and Les Cottrell. Page created: June 6 2003.

Central Computer Access | Computer Networking | Network Group | ICFA-NTF Monitoring

SLAC path to Internet2 node: SoX (Southern Crossroads)located at Atlanta has been changed

The route from Sunnyvale to Atlanta to Sunnyvale shifted from via Houston to via Indianapolis Abilene map .

How this situation is seen via our ABw monitoring is in following graph. You can see that available bandwith increased after change at 6:45 PDT (blue line) in factor 2. There is also visible that Iperf monitoring (black bars) nearly doesn't recognize the changes. (We have learnt that Iperf must be tuned for new situation.)

This case is another example of the possibilities how to discover such network changes via monitoring of available bandwidth. (See simmilar case: Daresbury-upgrade or Abilene in May )

Available bandwidth to node1.sox.i2.edu during last 24 hours (July 22-23 2003).

Parallel with this we are running traceroute monitoring (every hour) so the changes has been confirmed by this. See our traceroute monitor table at: http://www.slac.stanford.edu/comp/net/bandwidth-tests/hercules/html/slac_wan_bw_tests.html#node1.sox.i2.edu (Unfortunately, the Abwe&Iperf and the Traceroutes analysis are in the "Slac-only visible space".)

In reality the path is much shorter now (from 17 to 11 hops) as can be seen from the folowing traceroutes:

##(07/23/2003 06:19:44 1058966384)  traceroute to node1.sox.i2.edu 
##(07/23/2003 06:19:44 1058966384)   1  rtr-gsr-test (134.79.243.1)  0.226 ms
##(07/23/2003 06:19:44 1058966384)   2  rtr-dmz1-ger (134.79.135.15)  0.299 ms
##(07/23/2003 06:19:44 1058966384)   3  i2-gateway.stanford.edu (192.68.191.83)  0.240 ms
##(07/23/2003 06:19:44 1058966384)   4  STAN.POS.calren2.NET (171.64.1.213)  0.379 ms
##(07/23/2003 06:19:44 1058966384)   5  SUNV--STAN.POS.calren2.net (198.32.249.73)  0.624 ms
##(07/23/2003 06:19:44 1058966384)   6  C2-QANH-GSR-QSV-GSR.ATM.calren2.net (198.32.249.154)  21.206 ms
##(07/23/2003 06:19:44 1058966384)   7  USC--QAnh.POS.calren2.net (198.32.248.18)  21.801 ms
##(07/23/2003 06:19:44 1058966384)   8  ISI--USC.POS.calren2.net (198.32.248.26)  22.418 ms
##(07/23/2003 06:19:44 1058966384)   9  UCLA--ISI.POS.calren2.net (198.32.248.30)  22.905 ms
##(07/23/2003 06:19:44 1058966384)  10  dc-lax-12410a--c2-ucla-gsr-atm.cenic.net (137.164.22.5)  23.927 ms
##(07/23/2003 06:19:44 1058966384)  11  hpr-lax-12410--dc-lax-12410a-ge.cenic.net (137.164.22.13)  24.065 ms
##(07/23/2003 06:19:44 1058966384)  12  abilene-LA--hpr-lax-gsr1-10ge.cenic.net (137.164.25.3)  16.318 ms
##(07/23/2003 06:19:44 1058966384)  13  hstnng-losang.abilene.ucaid.edu (198.32.8.22)  47.867 ms
##(07/23/2003 06:19:44 1058966384)  14  atlang-hstnng.abilene.ucaid.edu (198.32.8.34)  61.810 ms
##(07/23/2003 06:19:44 1058966384)  15  atla-atlang.abilene.ucaid.edu (198.32.11.109)  61.832 ms
##(07/23/2003 06:19:44 1058966384)  16  sox-rtr.abilene.sox.net (199.77.193.9)  62.302 ms
##(07/23/2003 06:19:44 1058966384) SUMMARY: numhops=17;

##(07/23/2003 07:49:22 1058971762) traceroute to node1.sox.i2.edu 
##(07/23/2003 07:49:22 1058971762)   1  rtr-gsr-test (134.79.243.1)  0.293 ms
##(07/23/2003 07:49:22 1058971762)   2  rtr-dmz1-ger (134.79.135.15)  0.348 ms
##(07/23/2003 07:49:22 1058971762)   3  i2-gateway.stanford.edu (192.68.191.83)  0.242 ms
##(07/23/2003 07:49:22 1058971762)   4  STAN.POS.calren2.NET (171.64.1.213)  0.387 ms
##(07/23/2003 07:49:22 1058971762)   5  SUNV--STAN.POS.calren2.net (198.32.249.73)  0.742 ms
##(07/23/2003 07:49:22 1058971762)   6  Abilene--QSV.POS.calren2.net (198.32.249.162)  0.818 ms
##(07/23/2003 07:49:22 1058971762)   7  kscyng-snvang.abilene.ucaid.edu (198.32.8.103)  36.146 ms
##(07/23/2003 07:49:22 1058971762)   8  iplsng-kscyng.abilene.ucaid.edu (198.32.8.80)  45.389 ms
##(07/23/2003 07:49:22 1058971762)   9  atla-iplsng.abilene.ucaid.edu (198.32.8.78)  56.312 ms
##(07/23/2003 07:49:22 1058971762)  10  sox-rtr.abilene.sox.net (199.77.193.9)  56.662 ms
##(07/23/2003 09:20:13 1058977213) SUMMARY: numhops=11;

If the changes are permanent or just for couple of days we will see in next days.

*jn* Page owner: Jiri Navratil