two questions - SWAG answers entertained

Marshall Eubanks tme at multicasttech.com
Thu Oct 4 17:01:19 UTC 2007



On Oct 4, 2007, at 11:58 AM, bmanning at vacation.karoshi.com wrote:

>
>
> one:  AS hop count for average e2e packet flow, eg. from origin to  
> destination,
> 	how many ASN's will a packet traverse?
>

You might look at Figure 8c of

http://www.multicasttech.com/status/

If you assume that destinations IP addresses are selected at random,  
that tells you the PDF of the AS hop counts from here.

The mode is 3 hops.

Here is the data for Noon EDT, in case you want to do more.

     # hops  = Number of transit AS hops required to reach the source  
from AS 16517
## hop_histogram  Unicast  AS Hop Histogram
## hop_histogram  Number of Hops | Number of ASN | Number of Prefixes  
| Address Space Used
## hop_histogram
# hop_histogram   1      1    968  2.78565e+07
# hop_histogram   2   1587  32780  7.74648e+08
# hop_histogram   3  12829 122320  1.06436e+09
# hop_histogram   4   8754  56473  2.98075e+08
# hop_histogram   5   2549  14877  4.19192e+07
# hop_histogram   6    432   1932  1.18231e+07
# hop_histogram   7     39    215  872786
# hop_histogram   8      6     32  50112
# hop_histogram   9      0      0  0
# hop_histogram  10      0      0  0
# hop_histogram  11      0      0  0
# hop_histogram  12      0      0  0
# hop_histogram  13      0      0  0
# hop_histogram  14      1      1  4094

This of course is polluted somewhat by as path prepending, which  
could be stripped off if desired.

Regards
Marshall

> two:  number/location of IX that monitor/forbid transit across  
> exchange fabric?
>
>
> --bill (doing grunt work for a study on Landauer Entropy)




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