Here are the biggest autonomous systems in terms of peer counts, broken down by the issuing registry. Large networks typically span more than one region, but the issuing registry is a good indicator of the network's primary coverage area.
North America
| MCI Communications Services, Inc. d/b/a Verizon Business | 701 UUNET | 2872 peers |
| AT&T WorldNet Services | 7018 ATT-INTERNET4 | 2506 peers |
| Sprint | 1239 SPRINTLINK | 2011 peers |
| Level 3 Communications | 3356 LEVEL3 | 1883 peers |
| Cogent/PSI | 174 COGENT | 1811 peers |
| Qwest | 209 ASN-QWEST | 1482 peers |
| Global Crossing Ltd. | 3549 GBLX | 1119 peers |
| Time Warner Telecom, Inc. | 4323 TWTC | 966 peers |
| Hurricane Electric | 6939 HURRICANE | 891 peers |
| AT&T Internet Services | 7132 SBIS-AS | 795 peers |
Europe
| COLT Telecommunications | 8220 COLT | 548 peers |
| Tiscali Intl Network BV | 3257 TISCALI-BACKBONE | 514 peers |
| Deutsche Telekom AG | 3320 DTAG | 450 peers |
| Interoute Communications Ltd | 8928 INTEROUTE | 370 peers |
| JSC Company TransTeleCom | 20485 TRANSTELECOM | 345 peers |
| RTComm.RU Autonomous System | 8342 RTCOMM-AS | 317 peers |
| Golden Telecom, Moscow, Russia | 3216 SOVAM-AS | 314 peers |
| RCS & RDS S.A. | 8708 RDSNET | 245 peers |
| BT European Backbone | 5400 BT | 215 peers |
| GTS Polska Sp. z o.o. | 8246 GTS-POLSKA-AS | 207 peers |
Asia/Pacific
| Korea Telecom | 4766 KIXS-AS-KR | 313 peers |
| Asia Netcom Corporation | 10026 ANC | 251 peers |
| SingTel Optus Pty Ltd | 7474 OPTUSCOM-AS01-AU | 182 peers |
| Reach Network Border AS | 4637 REACH | 157 peers |
| Hanaro Telecom Inc. | 9318 HANARO-AS | 138 peers |
| Videsh Sanchar Nigam Ltd. Autonomous System | 4755 VSNL-AS | 134 peers |
| JAPAN TELECOM CO.,LTD. | 4725 ODN | 133 peers |
| BHARTI BT INTERNET LTD. | 9498 BBIL-AP | 130 peers |
| SK Global co., Ltd | 18302 SKG_NW-AS-KR | 126 peers |
| Singapore Telecom | 7473 SINGTEL-AS-AP | 118 peers |
Latin America
| S.A. | 27757 ANDINATEL | 22 peers |
| Cooperaci�n Latino Americana de Redes Avanzadas | 27750 ASN27750 | 15 peers |
| Uninet S.A. de C.V. | 28513 Uninet S.A. de C.V. | 14 peers |
| Multim�dia | 27664 CTBC | 10 peers |
| CO.PA.CO. | 27768 CO.PA.CO. | 9 peers |
| Amnet Telecomunicaciones S.A. | 27742 ASN27742 | 8 peers |
| Chile | 27678 NIC | 7 peers |
| TEL Comunicacion S.A. de C.V. | 28502 G | 7 peers |
| S.A. E.M.A. | 27765 TRANSNEXA | 7 peers |
| Aeprovi | 27814 Aeprovi | 6 peers |
Africa
