asn.dev

Observed topology

AS13977 CTELCO

Upstreams 4 carry this network
Downstreams 48 this network carries
Adjacent (IPv4) 51
Adjacent (IPv6) 8

Transit

Upstream networks

inferred

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.

ASNetworkTypeFamiliesPaths seen
AS6461Zayo BandwidthTransitIPv4 IPv626,150
AS174Cogent Communications, LLCTransitIPv4 IPv619,943
AS63243SynergentUnclassifiedIPv434
AS33422New England Telehealth ConsortiumUnclassifiedIPv430

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

inferred

Networks for which AS13977 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS13672FidiumUnclassifiedIPv42,596
AS32645FidiumUnclassifiedIPv41,836
AS54086Single Digits, Inc.UnclassifiedIPv4696
AS14671FairPoint CommunicationsUnclassifiedIPv4304
AS13673FidiumUnclassifiedIPv4297
AS399353Netafy, Inc.UnclassifiedIPv4 IPv6270
AS32508Granite State CommunicationsUnclassifiedIPv4243
AS55128McFarlane Associates LLCUnclassifiedIPv4 IPv6188
AS14437C&S WHOLESALE GROCERS INC.UnclassifiedIPv4156
AS54257Vermont State CollegesUnclassifiedIPv4121
AS33555Stonemarche Network CoOp.UnclassifiedIPv4118
AS400893Fiber Connect, LLC.UnclassifiedIPv496
AS400848DHI TECHNICAL SERVICES LLCHostingIPv4 IPv693
AS401455Clearline Communications, Inc.UnclassifiedIPv4 IPv693
AS394653Bar Harbor Bank & TrustUnclassifiedIPv473
AS53784Southern New Hampshire Health SystemUnclassifiedIPv471
AS17152Bates CollegeUnclassifiedIPv4 IPv662
AS63281Vermont JudiciaryUnclassifiedIPv460
AS395001State of MaineUnclassifiedIPv459
AS22270Bangor Savings BankUnclassifiedIPv459
AS401340Hussey Communications IncUnclassifiedIPv459
AS40229MaineHealth Maine Medical CenterUnclassifiedIPv459
AS396437COMMUNICATIONS LABORATORIESUnclassifiedIPv459
AS394174American International Distribution CorporationUnclassifiedIPv459
AS394632Catholic Medical CenterUnclassifiedIPv459
AS46925PAVLOV MEDIA INCUnclassifiedIPv459
AS393568ITT CorporationUnclassifiedIPv458
AS30034The Vermont Country Store, Inc.UnclassifiedIPv455
AS53322Viking Global Investors LPUnclassifiedIPv435
AS40737EMF Inc.UnclassifiedIPv432
AS26440Sprague Operating Resources LLCUnclassifiedIPv432
AS397398Brewster AcademyUnclassifiedIPv422
AS6248DEKA Research & Development CorpUnclassifiedIPv420
AS30669Camden National BankUnclassifiedIPv418
AS62630Husson UniversityUnclassifiedIPv416
AS55175RainWorxUnclassifiedIPv413
AS395342Exeter HospitalUnclassifiedIPv413
AS25937Trans-Video, Inc.UnclassifiedIPv413
AS11197Dartmouth-Hitchcock Medical CenterUnclassifiedIPv412
AS22847Bowdoin CollegeUnclassifiedIPv4 IPv69
AS53549Hussey Seating CompanyUnclassifiedIPv48
AS46820Littleton Regional HospitalUnclassifiedIPv48
AS63326C Squared Systems, LLCUnclassifiedIPv48
AS63243SynergentUnclassifiedIPv48
AS36501GARMIN INTERNATIONAL INC.UnclassifiedIPv47
AS10858Hypertherm Inc.UnclassifiedIPv42
AS398923MainePERSUnclassifiedIPv41
AS40757MMG Insurance CompanyUnclassifiedIPv41

Adjacency

Adjacent networks

60 shown

Every AS seen directly next to AS13977 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS6461Zayo BandwidthTransitIPv4 IPv631,230
AS174Cogent Communications, LLCTransitIPv4 IPv623,121
AS13672FidiumUnclassifiedIPv42,618
AS32645FidiumUnclassifiedIPv41,836
AS54086Single Digits, Inc.UnclassifiedIPv4696
AS14671FairPoint CommunicationsUnclassifiedIPv4304
AS13673FidiumUnclassifiedIPv4297
AS399353Netafy, Inc.UnclassifiedIPv4 IPv6270
AS32508Granite State CommunicationsUnclassifiedIPv4243
AS55128McFarlane Associates LLCUnclassifiedIPv4 IPv6188
AS14437C&S WHOLESALE GROCERS INC.UnclassifiedIPv4156
AS54257Vermont State CollegesUnclassifiedIPv4121
AS33555Stonemarche Network CoOp.UnclassifiedIPv4118
AS400893Fiber Connect, LLC.UnclassifiedIPv496
AS400848DHI TECHNICAL SERVICES LLCHostingIPv4 IPv693
AS401455Clearline Communications, Inc.UnclassifiedIPv4 IPv693
AS394653Bar Harbor Bank & TrustUnclassifiedIPv473
AS53784Southern New Hampshire Health SystemUnclassifiedIPv471
AS17152Bates CollegeUnclassifiedIPv4 IPv662
AS63281Vermont JudiciaryUnclassifiedIPv460
AS395001State of MaineUnclassifiedIPv459
AS401340Hussey Communications IncUnclassifiedIPv459
AS46925PAVLOV MEDIA INCUnclassifiedIPv459
AS394632Catholic Medical CenterUnclassifiedIPv459
AS394174American International Distribution CorporationUnclassifiedIPv459
AS40229MaineHealth Maine Medical CenterUnclassifiedIPv459
AS396437COMMUNICATIONS LABORATORIESUnclassifiedIPv459
AS22270Bangor Savings BankUnclassifiedIPv459
AS393568ITT CorporationUnclassifiedIPv458
AS30034The Vermont Country Store, Inc.UnclassifiedIPv455
AS63243SynergentUnclassifiedIPv442
AS53322Viking Global Investors LPUnclassifiedIPv435
AS40737EMF Inc.UnclassifiedIPv432
AS26440Sprague Operating Resources LLCUnclassifiedIPv432
AS33422New England Telehealth ConsortiumUnclassifiedIPv430
AS397398Brewster AcademyUnclassifiedIPv422
AS6248DEKA Research & Development CorpUnclassifiedIPv420
AS30669Camden National BankUnclassifiedIPv418
AS62630Husson UniversityUnclassifiedIPv416
AS55175RainWorxUnclassifiedIPv413
AS395342Exeter HospitalUnclassifiedIPv413
AS25937Trans-Video, Inc.UnclassifiedIPv413
AS11197Dartmouth-Hitchcock Medical CenterUnclassifiedIPv412
AS22847Bowdoin CollegeUnclassifiedIPv4 IPv69
AS53549Hussey Seating CompanyUnclassifiedIPv48
AS46820Littleton Regional HospitalUnclassifiedIPv48
AS63326C Squared Systems, LLCUnclassifiedIPv48
AS36501GARMIN INTERNATIONAL INC.UnclassifiedIPv47
AS10858Hypertherm Inc.UnclassifiedIPv42
AS40757MMG Insurance CompanyUnclassifiedIPv41
AS398923MainePERSUnclassifiedIPv41

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

recorded

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.

ExchangeLocationTheir addressMember ports
Boston Internet ExchangeBoston, United States206.108.236.6988

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.