Observed topology
AS23855 SINGAREN-GIX-AS-AP Singapore Advanced Research and Education Network
Transit
Upstream networks
Networks observed carrying traffic for AS23855: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS4637 | Telstra Global | Unclassified | IPv4 IPv6 | 69 |
| AS136968 | SingAREN | Education | IPv4 | 48 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 17 |
| AS23864 | Singapre Advance Research and Education Network - National Grid Office - IHPC | Hosting | IPv4 | 6 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 3 |
| AS38229 | Lanka Education & Research Network, NREN | Unclassified | IPv4 IPv6 | 3 |
| AS1103 | SURF B.V. | Unclassified | IPv4 IPv6 | 3 |
| AS17639 | Converge ICT Solutions Inc. | Unclassified | IPv4 | 2 |
| AS7660 | Asia Pacific Advanced Network - Japan | Unclassified | IPv4 | 2 |
| AS293 | ESnet | Unclassified | IPv4 | 2 |
| AS38001 | NewMedia Express Pte Ltd | Hosting | IPv4 | 2 |
| AS134148 | SingAREN | Unclassified | IPv6 | 2 |
Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you.
Transit
Downstream networks
Networks for which AS23855 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS7497 | Computer Network Information Center of Chinese Academy of Sciences (CNIC-CAS) | Education | IPv4 IPv6 | 631 |
| AS23767 | A-STAR | Unclassified | IPv4 | 375 |
| AS9419 | Nanyang Technological University | Education | IPv4 IPv6 | 103 |
| AS132398 | Science and Engineering Institutes | Unclassified | IPv4 IPv6 | 94 |
| AS23864 | Singapre Advance Research and Education Network - National Grid Office - IHPC | Hosting | IPv4 IPv6 | 57 |
| AS293 | ESnet | Unclassified | IPv4 IPv6 | 56 |
| AS134148 | SingAREN | Unclassified | IPv4 IPv6 | 48 |
| AS9270 | National Infomation Society Agency | Education | IPv4 | 21 |
| AS131475 | Singapore Institute of Technology | Unclassified | IPv4 | 10 |
| AS150725 | National University of Singapore | Unclassified | IPv4 | 6 |
| AS9264 | Academia Sinica | Education | IPv4 IPv6 | 6 |
| AS45259 | Bruhaas (B) Sdn Bhd | Unclassified | IPv4 | 5 |
| AS50999 | King Abdullah University of Science and Technology | Unclassified | IPv6 | 4 |
| AS9821 | Department of Science and Technology | Education | IPv4 | 4 |
| AS137207 | Joint Universities Computer Centre Limited | Unclassified | IPv4 IPv6 | 3 |
| AS24490 | Trans-Eurasia Information Network (TEIN2) - SG | Unclassified | IPv4 IPv6 | 3 |
| AS4538 | China Education and Research Network Center | Education | IPv4 | 2 |
| AS206350 | Oman Research and education Network (OMREN) | Unclassified | IPv6 | 1 |
Adjacency
Adjacent networks
Every AS seen directly next to AS23855 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS7660 | Asia Pacific Advanced Network - Japan | Unclassified | IPv4 IPv6 | 2,263 |
| AS38229 | Lanka Education & Research Network, NREN | Unclassified | IPv4 IPv6 | 2,239 |
| AS293 | ESnet | Unclassified | IPv4 IPv6 | 1,842 |
| AS24490 | Trans-Eurasia Information Network (TEIN2) - SG | Unclassified | IPv4 IPv6 | 1,362 |
| AS7497 | Computer Network Information Center of Chinese Academy of Sciences (CNIC-CAS) | Education | IPv4 IPv6 | 680 |
| AS134148 | SingAREN | Unclassified | IPv4 IPv6 | 579 |
| AS23767 | A-STAR | Unclassified | IPv4 | 375 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 257 |
| AS137207 | Joint Universities Computer Centre Limited | Unclassified | IPv4 IPv6 | 256 |
| AS9885 | NKN INTERNET GATEWAY NETWORK | Education | IPv4 IPv6 | 190 |
| AS9270 | National Infomation Society Agency | Education | IPv4 IPv6 | 189 |
| AS136968 | SingAREN | Education | IPv4 | 161 |
| AS4637 | Telstra Global | Unclassified | IPv4 IPv6 | 157 |
| AS23864 | Singapre Advance Research and Education Network - National Grid Office - IHPC | Hosting | IPv4 IPv6 | 144 |
| AS9419 | Nanyang Technological University | Education | IPv4 IPv6 | 103 |
| AS132398 | Science and Engineering Institutes | Unclassified | IPv4 IPv6 | 95 |
| AS1103 | SURF B.V. | Unclassified | IPv4 IPv6 | 45 |
| AS9264 | Academia Sinica | Education | IPv4 IPv6 | 15 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 13 |
| AS131475 | Singapore Institute of Technology | Unclassified | IPv4 | 10 |
| AS150725 | National University of Singapore | Unclassified | IPv4 | 6 |
| AS45259 | Bruhaas (B) Sdn Bhd | Unclassified | IPv4 | 5 |
| AS50999 | King Abdullah University of Science and Technology | Unclassified | IPv6 | 4 |
| AS9821 | Department of Science and Technology | Education | IPv4 | 4 |
| AS38001 | NewMedia Express Pte Ltd | Hosting | IPv4 | 4 |
| AS206350 | Oman Research and education Network (OMREN) | Unclassified | IPv4 IPv6 | 4 |
| AS17639 | Converge ICT Solutions Inc. | Unclassified | IPv4 | 3 |
| AS4538 | China Education and Research Network Center | Education | IPv4 | 2 |
| AS7575 | Australian Academic and Research Network (AARNet) | Education | IPv4 | 1 |
| AS35280 | F5 Networks SARL | Hosting | IPv4 | 1 |
Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.
Interconnection
Exchange presence
Internet exchanges where Packet Clearing House has a port recorded for AS23855, largest fabric first. An exchange is shared switching where networks interconnect directly rather than paying a transit provider to carry traffic between them, so turning up at one is a deliberate choice about how this network wants to be reached. Each name opens that exchange's own page, with its peering LANs and every other network recorded on it. Recorded at 3 exchanges across 2 countries and 1 region.
| Exchange | Location | Their address | Member ports |
|---|---|---|---|
| Singapore Internet Exchange | Singapore, Singapore | 103.16.102.28 | 273 |
| JPIX Tokyo | Tokyo, Japan | 210.171.225.159 | 259 |
| Singapore Open Exchange | Singapore, Singapore | 198.32.141.144 | 24 |
Unlike the tables above, this is recorded rather than inferred. An address on a peering LAN is at that exchange by definition. Two carve-outs all the same. Member ports counts every participant at the exchange, not this network's ports, so read it as a size proxy. And an absent exchange means PCH has no record of it, not that the network is not there.
Provenance
Where this comes from
Derived from routing tables collected at 2026-08-08 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.02M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.
Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.
Exchange presence comes from a separate dataset: the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member ports, licensed CC BY-NC-SA 3.0.
PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.