perfSONAR User Q&A and Other Discussion

[Matthew J Zekauskas <>]

A note to Research Support <> should help for 
Internet2-related queries; if there was a particular backbone issue 
found, someone from an end site (or regional) contacting the Internet2 
NOC would also be appropriate.

I don't believe latency is the issue here.    When using mtr, or 
traceroute, be aware that the routers will preferentially do other tasks 
to responding to ping or TTL=0 events, so the reported latency can be 
higher (occasionally much higher) than transiting packets experience.

FWIW, from a site in los angeles to chicago (pc's near the router) the 
RTT is 58.3 ms; from los angeles to kansas city it is 47.2 ms, which is 
in-line with the measurements below.   chicago to kans is 11.1 to 11.2, 
which matches the measurements from the other direction.  I might be 
able to dig up some of the rough fiber mileage measurements that show 
this is basically speed of light through fiber distance, but the numbers 
I have don't account for a bunch of metro fiber.

I looked at the maddash owamp UI, and it looks like there are no packet 
drops detected along the path, either.

--Matt.

On 7/30/14, 12:40 PM, Manoj Kumar Jha wrote:
> Hello,
>     We don't know whether this is an appropriate forum to raise this 
> issue.  If not, please help us in diverting it to proper mailing list.
>
>
> The perfsonar throughput from Purdue to Caltech is in lower range (~ 
> 600 Mbps) if we compare to other sites.   Throughput between Purdue 
> and Caltech can be found on following link
>
> http://tinyurl.com/oc95jzj
>
>
> Following is the output from the tool 'mtr' from Purdue to Caltech 
> perfsonar boxes.
>
>
> """
> [root@perfsonar-cms2
>  ~]# mtr --report perfsonar.ultralight.org
> HOST: perfsonar-cms2.itns.purdue. Loss%   Snt   Last   Avg  Best Wrst 
> StDev
>   1. math-g109-c9508-01-vlan743.t  0.0%    10    0.4   0.4   0.4 0.6   
> 0.0
>   2. math-g190-c7710-02-e2-4.tcom  0.0%    10    1.5   0.8   0.5 1.5   
> 0.3
>   3. math-g190-c7710-01-e2-1.tcom  0.0%    10    0.7   0.6   0.4 0.8   
> 0.1
>   4. tel-210-c9006-01-hu0-1-0-1.t  0.0%    10    0.7   0.7   0.6 0.9   
> 0.1
>   5. indiana-gigapop-ctc-internet  0.0%    10    1.6   1.6   1.6 1.8   
> 0.1
>   6. et-10-0-0.101.rtr.chic.net.i  0.0%    10    6.4   6.4   6.1 6.9   
> 0.3
>   7. et-10-0-0.106.rtr.kans.net.i  0.0%    10   17.6  17.6  17.3 
> 18.1   0.3
>   8. et-1-0-0.109.rtr.hous.net.in  0.0%    10   32.0  32.3  31.9 
> 32.8   0.3
>   9. hpr-lax-hpr2--i2-houston.cen  0.0%    10   65.2  67.3  64.5 
> 78.0   5.3
>  10. hpr-svl-ln-peer9.cenic.net    0.0%    10   65.9  65.6  65.3 
> 65.9   0.2
>  11. perfsonar.ultralight.org      0.0%    10   65.5  65.5  65.1 
> 66.0   0.3
> [root@perfsonar-cms2
>  ~]#
>
> """
>
>
>
> Packet round trip time for Chiacgo (chic.net) -->  Kansas (kans.net) 
> --> Houston (hous.net.in and houston.cent)  is higher if we compare to 
> other hops. In the reverse direction, packet rtt is higher between 
> 'lax-hpr' and 'kans.net'.  Following is the output of the tool 
> 'traceroute'  from Caltech to Purdue perfsonar boxes.
> ^^^
>
> [root@gridftp1
>  ~]# traceroute  perfsonar-cms2.itns.purdue.edu
> traceroute to perfsonar-cms2.itns.purdue.edu (128.211.143.4), 30 hops
> max, 60 byte packets
>  1  ve64-chopin.86.84.192.in-addr.arpa (192.84.86.97)  0.209 ms 0.245
> ms  0.277 ms
>  2  hpr-svl-ln-peer8.cenic.net (137.164.26.106)  12.134 ms  1.222 ms  
> 12.252 ms
>  3  hpr-i2-newnet--lax-hpr.cenic.net (137.164.26.134)  1.279 ms 1.277
> ms 137.164.26.201 (137.164.26.201)  1.248 ms
>  4  et-1-0-0.111.rtr.hous.net.internet2.edu (198.71.45.20)  33.567 ms
> 33.517 ms  33.498 ms
>  5  et-5-0-0.109.rtr.kans.net.internet2.edu (198.71.45.17)  48.426 ms
> 48.420 ms  48.401 ms
>  6  et-9-0-0.106.rtr.chic.net.internet2.edu (198.71.45.14)  59.527 ms
> 59.298 ms  59.256 ms
>  7  ae-1.2063.rtr.ictc.indiana.gigapop.net (149.165.254.185) 63.895
> ms  64.124 ms  64.126 ms
>  8  * * *
>  9  * * *
> 10  * * *
> 11  perfsonar-cms2.itns.purdue.edu (128.211.143.4)  64.952 ms 64.955
> ms  65.289 ms
>
>
> ^^^
> Is the packet rtt value to/from Kansas hop is under normal value ?
>
> Thanks,
> Manoj