Observed topology
AS13977 CTELCO
Transit
Upstream networks
Networks observed carrying traffic for AS13977: 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 |
|---|---|---|---|---|
| AS6461 | Zayo Bandwidth | Transit | IPv4 IPv6 | 26,150 |
| AS174 | Cogent Communications, LLC | Transit | IPv4 IPv6 | 19,943 |
| AS63243 | Synergent | Unclassified | IPv4 | 34 |
| AS33422 | New England Telehealth Consortium | Unclassified | IPv4 | 30 |
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 AS13977 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS13672 | Fidium | Unclassified | IPv4 | 2,596 |
| AS32645 | Fidium | Unclassified | IPv4 | 1,836 |
| AS54086 | Single Digits, Inc. | Unclassified | IPv4 | 696 |
| AS14671 | FairPoint Communications | Unclassified | IPv4 | 304 |
| AS13673 | Fidium | Unclassified | IPv4 | 297 |
| AS399353 | Netafy, Inc. | Unclassified | IPv4 IPv6 | 270 |
| AS32508 | Granite State Communications | Unclassified | IPv4 | 243 |
| AS55128 | McFarlane Associates LLC | Unclassified | IPv4 IPv6 | 188 |
| AS14437 | C&S WHOLESALE GROCERS INC. | Unclassified | IPv4 | 156 |
| AS54257 | Vermont State Colleges | Unclassified | IPv4 | 121 |
| AS33555 | Stonemarche Network CoOp. | Unclassified | IPv4 | 118 |
| AS400893 | Fiber Connect, LLC. | Unclassified | IPv4 | 96 |
| AS400848 | DHI TECHNICAL SERVICES LLC | Hosting | IPv4 IPv6 | 93 |
| AS401455 | Clearline Communications, Inc. | Unclassified | IPv4 IPv6 | 93 |
| AS394653 | Bar Harbor Bank & Trust | Unclassified | IPv4 | 73 |
| AS53784 | Southern New Hampshire Health System | Unclassified | IPv4 | 71 |
| AS17152 | Bates College | Unclassified | IPv4 IPv6 | 62 |
| AS63281 | Vermont Judiciary | Unclassified | IPv4 | 60 |
| AS395001 | State of Maine | Unclassified | IPv4 | 59 |
| AS22270 | Bangor Savings Bank | Unclassified | IPv4 | 59 |
| AS401340 | Hussey Communications Inc | Unclassified | IPv4 | 59 |
| AS40229 | MaineHealth Maine Medical Center | Unclassified | IPv4 | 59 |
| AS396437 | COMMUNICATIONS LABORATORIES | Unclassified | IPv4 | 59 |
| AS394174 | American International Distribution Corporation | Unclassified | IPv4 | 59 |
| AS394632 | Catholic Medical Center | Unclassified | IPv4 | 59 |
| AS46925 | PAVLOV MEDIA INC | Unclassified | IPv4 | 59 |
| AS393568 | ITT Corporation | Unclassified | IPv4 | 58 |
| AS30034 | The Vermont Country Store, Inc. | Unclassified | IPv4 | 55 |
| AS53322 | Viking Global Investors LP | Unclassified | IPv4 | 35 |
| AS40737 | EMF Inc. | Unclassified | IPv4 | 32 |
| AS26440 | Sprague Operating Resources LLC | Unclassified | IPv4 | 32 |
| AS397398 | Brewster Academy | Unclassified | IPv4 | 22 |
| AS6248 | DEKA Research & Development Corp | Unclassified | IPv4 | 20 |
| AS30669 | Camden National Bank | Unclassified | IPv4 | 18 |
| AS62630 | Husson University | Unclassified | IPv4 | 16 |
| AS55175 | RainWorx | Unclassified | IPv4 | 13 |
| AS395342 | Exeter Hospital | Unclassified | IPv4 | 13 |
| AS25937 | Trans-Video, Inc. | Unclassified | IPv4 | 13 |
| AS11197 | Dartmouth-Hitchcock Medical Center | Unclassified | IPv4 | 12 |
| AS22847 | Bowdoin College | Unclassified | IPv4 IPv6 | 9 |
| AS53549 | Hussey Seating Company | Unclassified | IPv4 | 8 |
| AS46820 | Littleton Regional Hospital | Unclassified | IPv4 | 8 |
| AS63326 | C Squared Systems, LLC | Unclassified | IPv4 | 8 |
| AS63243 | Synergent | Unclassified | IPv4 | 8 |
| AS36501 | GARMIN INTERNATIONAL INC. | Unclassified | IPv4 | 7 |
| AS10858 | Hypertherm Inc. | Unclassified | IPv4 | 2 |
| AS398923 | MainePERS | Unclassified | IPv4 | 1 |
| AS40757 | MMG Insurance Company | Unclassified | IPv4 | 1 |
Adjacency
Adjacent networks
Every AS seen directly next to AS13977 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS6461 | Zayo Bandwidth | Transit | IPv4 IPv6 | 31,230 |
| AS174 | Cogent Communications, LLC | Transit | IPv4 IPv6 | 23,121 |
| AS13672 | Fidium | Unclassified | IPv4 | 2,618 |
| AS32645 | Fidium | Unclassified | IPv4 | 1,836 |
| AS54086 | Single Digits, Inc. | Unclassified | IPv4 | 696 |
| AS14671 | FairPoint Communications | Unclassified | IPv4 | 304 |
| AS13673 | Fidium | Unclassified | IPv4 | 297 |
| AS399353 | Netafy, Inc. | Unclassified | IPv4 IPv6 | 270 |
| AS32508 | Granite State Communications | Unclassified | IPv4 | 243 |
| AS55128 | McFarlane Associates LLC | Unclassified | IPv4 IPv6 | 188 |
| AS14437 | C&S WHOLESALE GROCERS INC. | Unclassified | IPv4 | 156 |
| AS54257 | Vermont State Colleges | Unclassified | IPv4 | 121 |
| AS33555 | Stonemarche Network CoOp. | Unclassified | IPv4 | 118 |
| AS400893 | Fiber Connect, LLC. | Unclassified | IPv4 | 96 |
| AS400848 | DHI TECHNICAL SERVICES LLC | Hosting | IPv4 IPv6 | 93 |
| AS401455 | Clearline Communications, Inc. | Unclassified | IPv4 IPv6 | 93 |
| AS394653 | Bar Harbor Bank & Trust | Unclassified | IPv4 | 73 |
| AS53784 | Southern New Hampshire Health System | Unclassified | IPv4 | 71 |
| AS17152 | Bates College | Unclassified | IPv4 IPv6 | 62 |
| AS63281 | Vermont Judiciary | Unclassified | IPv4 | 60 |
| AS395001 | State of Maine | Unclassified | IPv4 | 59 |
| AS401340 | Hussey Communications Inc | Unclassified | IPv4 | 59 |
| AS46925 | PAVLOV MEDIA INC | Unclassified | IPv4 | 59 |
| AS394632 | Catholic Medical Center | Unclassified | IPv4 | 59 |
| AS394174 | American International Distribution Corporation | Unclassified | IPv4 | 59 |
| AS40229 | MaineHealth Maine Medical Center | Unclassified | IPv4 | 59 |
| AS396437 | COMMUNICATIONS LABORATORIES | Unclassified | IPv4 | 59 |
| AS22270 | Bangor Savings Bank | Unclassified | IPv4 | 59 |
| AS393568 | ITT Corporation | Unclassified | IPv4 | 58 |
| AS30034 | The Vermont Country Store, Inc. | Unclassified | IPv4 | 55 |
| AS63243 | Synergent | Unclassified | IPv4 | 42 |
| AS53322 | Viking Global Investors LP | Unclassified | IPv4 | 35 |
| AS40737 | EMF Inc. | Unclassified | IPv4 | 32 |
| AS26440 | Sprague Operating Resources LLC | Unclassified | IPv4 | 32 |
| AS33422 | New England Telehealth Consortium | Unclassified | IPv4 | 30 |
| AS397398 | Brewster Academy | Unclassified | IPv4 | 22 |
| AS6248 | DEKA Research & Development Corp | Unclassified | IPv4 | 20 |
| AS30669 | Camden National Bank | Unclassified | IPv4 | 18 |
| AS62630 | Husson University | Unclassified | IPv4 | 16 |
| AS55175 | RainWorx | Unclassified | IPv4 | 13 |
| AS395342 | Exeter Hospital | Unclassified | IPv4 | 13 |
| AS25937 | Trans-Video, Inc. | Unclassified | IPv4 | 13 |
| AS11197 | Dartmouth-Hitchcock Medical Center | Unclassified | IPv4 | 12 |
| AS22847 | Bowdoin College | Unclassified | IPv4 IPv6 | 9 |
| AS53549 | Hussey Seating Company | Unclassified | IPv4 | 8 |
| AS46820 | Littleton Regional Hospital | Unclassified | IPv4 | 8 |
| AS63326 | C Squared Systems, LLC | Unclassified | IPv4 | 8 |
| AS36501 | GARMIN INTERNATIONAL INC. | Unclassified | IPv4 | 7 |
| AS10858 | Hypertherm Inc. | Unclassified | IPv4 | 2 |
| AS40757 | MMG Insurance Company | Unclassified | IPv4 | 1 |
| AS398923 | MainePERS | Unclassified | 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 AS13977, 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 1 exchange across 1 country and 1 region.
| Exchange | Location | Their address | Member ports |
|---|---|---|---|
| Boston Internet Exchange | Boston, United States | 206.108.236.69 | 88 |
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 2026-08-08 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,137 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.