The surprising centres of the Internet

A previous post, on “Barabási – Albert preferential attachment and the Internet“, gave a plot of  the Internet, as a sparsity map of its regular adjacency matrix, with the axes ordered by each ASes  eigencentrality:

Sparsity plot of the Internet adjacency matrix, with the nodes ordered by their Eigencentrality ranking.

Sparsity plot of the Internet adjacency matrix, for the UCLA IRL 2013-06 data-set, with the nodes ordered by their Eigencentrality ranking.

Each connection in the BGP AS graph is represented as a dot, connecting the AS on the one axis to the AS on the other. As the BGP AS graph is undirected, the plot ends up symmetric. The top-right corner of this plot shows that the most highly-ranked ASes are very densely interconnected. The distinct outline probably is indicative (characteristic?) of a tree-like hierarchy in the data.

Who are these top-ranked ASes though? Are they large, well-known telecommunications companies? The answer might be surprising.

The following table lists the highest eigencentrality-ranked ASes in the 2013-06 BGP AS graph from the UCL IRL Topology data-set, along with their ASN and degree (out of 41267 non-0-degree ASes):


Eigencentrality Rank

AS

Description

Degree

1

AS6939

Hurricane Electric

2781

2

AS9002

RETN Limited

1601

3

AS13237

euNetworks Managed Services GmbH

1094

4

AS34288

Public Schools in the Canton of Zug

1033

5

AS12859

BIT BV, Ede, The Netherlands

912

6

AS8468

ENTANET International Limited

933

7

AS42708

Portlane Networks AB

979

8

AS12779

IT.Gate S.p.A.

962

9

AS13030

Init Seven AG,CH

1101

10

AS31500

JSC GLOBALNET, St.Petersburg, RU.

1151

11

AS28917

JSC “TRC FIORD”, Moscow, RU

1083

12

AS12989

Eweka Internet Services B.V.

1198

13

AS19151

Broadband One Announcements, Florida, US.

1007

14

AS31133

OJSC MegaFon, Moscow, RU.

1141

15

AS8359

MTS / former CJSC COMSTAR-Direct, Moscow, RU

1217

16

AS29208

DialTelecom, CZ

878

17

AS8447

A1 Telekom Austria AG,

885

18

AS24482

SG.GS

858

19

AS8422

NetCologne GmbH

781

20

1267

WIND Telecomunicazioni S.p.A.

832

I can recognise at most a few of these networks. The rest I do not, and I assume are more regional players. I certainly wouldn’t have expected a Swiss schools network to be in this list. Interestingly, a majority, 11, of the top-20 Eigencentrality ranked networks in the above table appear clearly to be Europe based, and another 6 in western Russia, whose networks are likely to gravitate toward peering in western Europe (the European RIR, RIPE, is the RIR for Russia).

What then of the major telecommunications companies? Where do they rank? This is shown in the following table, listing some well-known ones, as determined by examining the Wikipedia page on Tier-1 ISPs and the annual Renesys report on the “Baker’s Dozen”:


Eigencentrality rank

ASN

Name [/ Other or prior name]

Degree

45

AS3356

Level 3

3949

70

AS174

Cogent

3909

96

AS1299

TeliaSonera

785

99

AS3257

Tinet / gtt / Inteliquent

955

108

AS3549

Level 3 / Global Crossing

1438

112

AS3491

PCCW Global

616

115

AS2914

NTT US / Verio

924

150

AS6461

Abovenet

1170

293

AS3320

Deutsche Telekom

550

307

AS1273

Vodafone / Cable & Wireless

315

313

AS6453

Tata Communications / Teleglobe

593

541

AS6762

Sparkle / Seabone / Telecom Italia

297

750

AS4323

tw telecom

1778

788

AS5400

British Telecom

196

886

AS2828

XO Communications

1101

924

AS4134

China Telecom

114

925

AS209

Centurylink / QWest

1531

930

AS701

Verizon Business / UUNet

2005

938

AS5511

Orange / OpenTransit

164

946

AS15290

Allstream /

189

951

AS1239

Sprint

860

969

AS7018

AT&T

2507

1142

AS3561

Centurylink / Savvis

354

A few of these major telecommunications have their operations split over multiple ASNs, notably Level-3, and might rank more highly otherwise. However, generally they all rank quite lowly, despite many having degrees at least as high as those top eigencentrality-ranked nodes.

So what’s going on? The answer, likely, is the IXP model prevalent in Europe, where smaller networks meet and peer very widely. This allows them to avoid paying the traditional telecommunications companies to exchange traffic. The larger IXPs reportedly carry as much daily traffic between the networks peering at them, as the largest ISPs do over their backbones. These IXPs also enable major content providers to peer directly with a great many networks, and there is evidence these major content providers have built out their connectivity widely in this way, rather than relying on the traditional large telecommunications companies to route their traffic for them.

IXPs and the large, densely peered meshes of smaller networks they enable seem now to be at the heart of the Internet. The structure of the Internet appears to have evolved, as well as our understanding of it, away from a tiered hierarchy of ISPs.

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