two questions - SWAG answers entertained

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

two: number/location of IX that monitor/forbid transit across exchange fabric?

--bill (doing grunt work for a study on Landauer Entropy)

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

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

wrong forum. there have been good formal measurement papers on this.
do a lit search.

randy

ere, this might be the ideal forum. citseer is very helpful,
  some formal analysis from a few data points. my request
  for SWAG data from operations folks was/is a way to sanity check
  simulation work that forms the basis for much of the formal
  papers. anyway...

  thanks to the kind folks who have (mercifully) responded off list.
  we now return you to the usual NANOG postings.

--bill

Are you able to share the identity/AS path of that outlier at 14, or at least
explain how somebody got a path length of 14 without any paths of lengths 9
through 13 showing up?

Yes -
Here it is :

  AS 3010 SPRINT-MRN-BLOCK | 1 prefixes | 1 prefixes & 1 ASN supported | 4094 Addresses | 14 hops | as path 174 3491 18734 28509 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010

here is the only address block :

*> 201.160.16.0/20 38.101.161.116 4001 0 174 3491 18734 28509 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 i

I assume that this is some odd internal Sprint thing - maybe a lab in Mexico as it is going through 28509 ?

   28509 MX-TCSC23-LACNIC [RUM] {62270 - cuernavaca - MO, MX} TV Cable S.A. de C.V.

None of the other 3001-3009 appear directly.

Could this be some new form of AS path prepending ? I really don't know.

Regards
Marshall

How vague can the data be?

Path length distribution:
        Hops in Path: Count
        1: 104395
        2: 2923484
        3: 13778037
        4: 17280238
        5: 9353555
        6: 3795923
        7: 1792676
        8: 822142
        9: 472420
        10: 258358
        11: 160412
        12: 104390
        13: 93137
        14: 66313
        15: 48547
        16: 22362
        17: 7044
        18: 5048
        19: 9684
        20: 5030
        21: 1469
        22: 852
        23: 497
        24: 132
        25: 132
        26: 229
        27: 1288
        28: 12080
        29: 1609
        30: 819
        31: 12
        32: 1
        34: 30
        35: 55

And just for kicks, prepends:

Prepend distribution:
        Prepends in Path: Count
        2: 3514603
        3: 1754138
        4: 1209997
        5: 562524
        6: 336495
        7: 263039
        8: 64786
        9: 85553
        10: 90446
        11: 89088
        12: 2722
        13: 18072
        14: 494
        15: 6
        16: 423
        17: 69
        20: 111
        21: 34
        22: 80
        25: 260

I've had a few questions about the data I posted. That was a total of
all ribs I have access to, not a summary of uniques. I thought maybe a
report of OIX would be a better example. Here's the full rib report:

Total prefixes seen in RIB: 238997
Total origin ASes seen in RIB: 26514
Total 32 bit ASes seen in RIB: 0
Total peer pairs seen in RIB: 55947

RIB Peers not found in all other tables: 4
RIB Prefixes not exactly matched in all other tables: 123
RIB more specific prefix count: 123

Number of unique prefixes in RIB compared against all data: 123
Number of unique origin ASes in RIB compared against all data: 4

Number of ASes announcing only one prefix: 11229
Number of Transit Only ASes: 125
RIB average path length: 4.09

All tables Total IP Coverage: 2549455474
59.4%
All tables Total IP Coverage including BOGON: 3220536059
75.0%
RIB Total IP Coverage: 1790591076
41.7%
RIB Total IP Coverage including BOGON: 3201119844
74.5%

RIB IP Coverage by Region
        RIB IP Coverage for
ARIN 1038310514 46.2%
        RIB IP Coverage for
APNIC 399476161 17.8%
        RIB IP Coverage for
RIPENCC 312598027 13.9%
        RIB IP Coverage for
RIPE 197332093 8.8%
        RIB IP Coverage for
JPIRR 110040248 4.9%
        RIB IP Coverage for
UNKNOWN 109583355 4.9%
        RIB IP Coverage for
LACNIC 68517416 3.0%
        RIB IP Coverage for
AFRINIC 12606792 0.6%

RIB Total AS
Coverage: 26514

RIB AS Coverage by Region
        RIB AS Coverage for
ARIN: 12525 47.2%
        RIB AS Coverage for
RIPE: 10418 39.3%
        RIB AS Coverage for
APNIC: 2648 10.0%
        RIB AS Coverage for
LACNIC: 377 1.4%
        RIB AS Coverage for
JPNIC: 150 0.6%
        RIB AS Coverage for
KRNIC: 131 0.5%
        RIB AS Coverage for
AFRINIC: 84 0.3%
        RIB AS Coverage for
ID-NIC: 77 0.3%
        RIB AS Coverage for
CNNIC: 52 0.2%
        RIB AS Coverage for
PRIVATE: 21 0.1%
        RIB AS Coverage for
TWNIC: 17 0.1%
        RIB AS Coverage for
VNNIC: 13 0.0%
        RIB AS Coverage for
IANA: 1 0.0%

Prefix length distribution
        /8: 20
        /9: 9
        /10: 16
        /11: 37
        /12: 136
        /13: 271
        /14: 483
        /15: 946
        /16: 9891
        /17: 4240
        /18: 6843
        /19: 14700
        /20: 17674
        /21: 15748
        /22: 20131
        /23: 21032
        /24: 126563
        /25: 619
        /26: 638
        /27: 353
        /28: 138
        /29: 102
        /30: 122
        /32: 50

Path length distribution:
        Hops in Path: Count
        1: 9247
        2: 579155
        3: 2947058
        4: 2928712
        5: 1317423
        6: 521409
        7: 264027
        8: 121191
        9: 73516
        10: 37090
        11: 23273
        12: 14804
        13: 13515
        14: 8818
        15: 7767
        16: 3740
        17: 885
        18: 888
        19: 1130
        20: 386
        21: 80
        22: 103
        23: 46
        24: 7
        25: 14
        26: 59
        27: 30
        28: 1164
        29: 7

Prepend length distribution:
        # Prepends in Path: Count
        2: 531052
        3: 283552
        4: 200956
        5: 90091
        6: 50456
        7: 45784
        8: 8428
        9: 15447
        10: 8736
        11: 15066
        12: 459
        13: 1489
        14: 46
        16: 67
        17: 22
        20: 14
        21: 2
        22: 8
        25: 4

Total AS Sets: 1874

Just out of interest, what's the difference between "RIPENCC" (the Regional Registry?) and "RIPE" (a vaguely defined group of people who contribute to the RIPE working group mailing lists and/or attend RIPE meetings and/or have some interest in IP networking in and around Europe and/or ... ?) here?

James

The nature of registry data leads to bugs like this, they should all be
RIPENCC.

jas

James Aldridge wrote: