Tier 2 network

Last updated

Internet Connectivity Distribution & Core.svg

A Tier 2 network is an Internet service provider which engages in the practice of peering with other networks, but which also purchases IP transit to reach some portion of the Internet. [1]


Tier 2 providers are the most common Internet service providers, as it is much easier to purchase transit from a Tier 1 network than to peer with them and attempt to become a Tier 1 carrier.

The term Tier 3 is sometimes also used to describe networks who solely purchase IP transit from other networks to reach the Internet.

List of large or important Tier 2 networks

Name AS Number August 2021 degree [2] [3] Reason
Hurricane Electric 69399243IPv4: Purchases transit from Arelion/AS1299. [4]
IPv6: Does not provide IPv6 routing/connectivity to Cogent/AS174. [5]
Telkom Indonesia International 7713551Purchases transit from Level3/AS3356, Cogent/AS174, Arelion/AS1299, NTT America/AS2914, Telecom Italia Sparkle/AS6762, Tata Communications/AS6453, Singtel/AS7473.
RETN 90021446Purchases transit from Level 3/AS3356.
next layer 1764987Purchases transit from Level 3/AS3356, Cogent/AS174, Arelion/AS1299, NTT America/AS2914, GTT/AS3257.
meerfarbig 34549688Purchases transit from Arelion/AS1299, Global Telecom & Technology (GTT)
Korea Telecom 4766578Purchases transit from Level3/AS3356, Arelion/AS1299, Cogent/AS174, Telecom Italia Sparkle/AS6762.
HGC Global 9304637Purchases transit from Cogent/AS174, NTT America/AS2914, Telecom Italia Sparkle/AS6762, Tata Communications/AS6453.
Fibrenoire 22652127Purchases transit from Arelion/AS1299, Cogent/AS174, Tata Communications/AS6453, GTT/AS3257.
SK broadband 9318537Purchases transit from Arelion/AS1299, Cogent/AS174, NTT America/AS2914, Tata Communications/AS6453, PCCW Global/AS3491, Verizon/AS701.
TDC 3292191Purchases transit from Level3/AS3356, Arelion/AS1299.
Internet Initiative Japan 2497329Purchases transit from Level3/AS3356, Cogent/AS174, Verizon/AS701, NTT America/AS2914.
Vodafone (formerly Cable and Wireless)1273303Purchases transit from Arelion/AS1299.
KDDI 2516308Purchases transit from Level3/AS3356, Arelion/AS1299, Verizon/AS701, Global Telecom & Technology (GTT)/AS3257.
PT Mora Telematika Indonesia 23947243Purchases transit from Cogent/AS174, Global Telecom & Technology (GTT)/AS3257, Hurricane Electric/AS6939.
China Telecom 4134/4809318Purchases transit from Cogent/AS174, Verizon/AS701, Level3/AS3356.
China Unicom 4837310Purchases transit from Cogent/AS174, Verizon/AS701,Sprint/AS1239, Level3/AS3356, Orange S.A./AS5511.
Chunghwa Telecom 3462364Purchases transit from Tata Communications/AS6453.
British Telecom 5400151Purchases transit from Level3/AS3356, Arelion/AS1299, NTT America/AS2914.
Comcast 7922192Purchases transit from Tata Communications/AS6453, NTT America/AS2914.
Tele2 (formerly SWIPNet)1257167Purchases transit from Sprint/AS1239, Cogent/AS174.
KCOM Group 1239069Purchases transit from KPN/AS286, Level 3/AS3356, Cogent/AS174, NTT America/AS2914.
Spirit Communications 271182Purchases transit from Level3/AS3356, Cogent/AS174, Arelion/AS1299, NTT America/AS2914.
Stealth Communications 800247Purchases transit from Cogent/AS174, NTT America/AS2914.
Internap 1474433Purchases transit from Cogent/AS174, NTT America/AS2914, Verizon/AS701.
FiberRing 3893035Purchases transit from NTT America/AS2914, Arelion/AS1299, Tata Communications/AS6453, Cogent/AS174.
Core-Backbone GmbH 338911311Purchases transit from Level3/AS3356, Arelion/AS1299.
Fiber Telecom 413272145Purchases transit from Level3/AS3356, GTT/AS3257, Telecom Italia Sparkle/AS6762, Arelion/AS1299.
Singtel 7473359Purchases transit from Arelion/AS1299, Zayo/AS6461, Tata Communications/AS6453 and PCCW Global/AS3491.
SG.GS 24482417Purchases IP transit from NTT America/AS2914, Cogent/AS174 and Tata Communications/AS6453.
Turk Telekom International
(d/b/a Euroweb.ro)
9121/6663250Purchases IP transit from Level3/AS3356, Arelion/AS1299, NTT America/AS2914, Deutsche Telekom Global Carrier/AS3320, China Telecom/AS4134&AS4809.

See also

Related Research Articles

<span class="mw-page-title-main">Internet</span> Global system of connected computer networks

The Internet is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing.

In computer networking, peering is a voluntary interconnection of administratively separate Internet networks for the purpose of exchanging traffic between the "down-stream" users of each network. Peering is settlement-free, also known as "bill-and-keep" or "sender keeps all", meaning that neither party pays the other in association with the exchange of traffic; instead, each derives and retains revenue from its own customers.

<span class="mw-page-title-main">Internet backbone</span> Vital infrastructure of the networks of the Internet

The Internet backbone may be defined by the principal data routes between large, strategically interconnected computer networks and core routers of the Internet. These data routes are hosted by commercial, government, academic and other high-capacity network centers, as well as the Internet exchange points and network access points, that exchange Internet traffic between the countries, continents, and across the oceans. Internet service providers, often Tier 1 networks, participate in Internet backbone traffic by privately negotiated interconnection agreements, primarily governed by the principle of settlement-free peering.

<span class="mw-page-title-main">Tier 1 network</span> Top level network on the internet

A Tier 1 network is an Internet Protocol (IP) network that can reach every other network on the Internet solely via settlement-free interconnection. Tier 1 networks can exchange traffic with other Tier 1 networks without paying any fees for the exchange of traffic in either direction. In contrast, some Tier 2 networks and all Tier 3 networks must pay to transmit traffic on other networks.

Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for voice calls for the delivery of voice communication sessions over Internet Protocol (IP) networks, such as the Internet.

An autonomous system (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain, that presents a common and clearly defined routing policy to the Internet. Each AS is assigned an autonomous system number (ASN), for use in Border Gateway Protocol (BGP) routing. Autonomous System Numbers are assigned to Local Internet Registries (LIRs) and end user organizations by their respective Regional Internet Registries (RIRs), which in turn receive blocks of ASNs for reassignment from the Internet Assigned Numbers Authority (IANA). The IANA also maintains a registry of ASNs which are reserved for private use.

Internet exchange points are common grounds of IP networking, allowing participant Internet service providers (ISPs) to exchange data destined for their respective networks. IXPs are generally located at places with preexisting connections to multiple distinct networks, i.e., datacenters, and operate physical infrastructure (switches) to connect their participants. Organizationally, most IXPs are each independent not-for-profit associations of their constituent participating networks. The primary alternative to IXPs is private peering, where ISPs directly connect their networks to each other.

Internet traffic is the flow of data within the entire Internet, or in certain network links of its constituent networks. Common traffic measurements are total volume, in units of multiples of the byte, or as transmission rates in bytes per certain time units.

LyonIX is the Internet eXchange point (IXP) of Lyon. LyonIX is managed by Rezopole, the non-profit organization supported by the Métropole de Lyon and the Auvergne – Rhône-Alpes region.

Level 3 Communications was an American multinational telecommunications and Internet service provider company headquartered in Broomfield, Colorado. It ultimately became a part of CenturyLink, where Level 3 President and CEO Jeff Storey was installed as Chief Operating Officer, becoming CEO of CenturyLink one year later in a prearranged succession plan.

<span class="mw-page-title-main">Xfinity</span> American cable provider

Comcast Cable Communications, LLC, doing business as Xfinity, is an American telecommunications business segment and division of Comcast Corporation used to market consumer cable television, internet, telephone, and wireless services provided by the company. The brand was first introduced in 2010; prior to that, these services were marketed primarily under the Comcast name.

Cogent Communications is a multinational internet service provider based in the United States. Cogent's primary services consist of Internet access and data transport, offered on a fiber optic, IP data-only network, along with colocation in data centers. Although Cogent is not a Tier 1 ISP by definition, due to lack of complete IPv6 connectivity, the company still advertises itself a Tier 1 ISP. There has been debate among networking professionals as to whether or not this amounts to false advertising.

<span class="mw-page-title-main">Internet transit</span> Service to connect ISP to the larger Internet

Internet transit is the service of allowing network traffic to cross or "transit" a computer network, usually used to connect a smaller Internet service provider (ISP) to the larger Internet. Technically, it consists of two bundled services:

<span class="mw-page-title-main">Exetel</span> Australian internet service provider

Exetel is an Australian ISP which provides ADSL, web hosting, VoIP, and other internet services to customers across Australia. Exetel's headquarters are in offices in Sydney, and its switching centres are distributed in capital city secure data centre facilities around mainland Australia.

PacketExchange was a British multinational network services provider based in London. Founded in 2002 by Jason Velody and Kieron O'Brien, both supported by Nigel Titley, Giles Heron, and Katie Snowball as the founding team, its network connected 45 points of presence across Europe, Asia, and the United States over a private backbone consisting primarily of multiple 10 Gigabit Ethernet links over dedicated wavelengths on a fiber-optic mesh.

<span class="mw-page-title-main">IP exchange</span> Telecommunications interconnection model

IP exchange or (IPX) is a telecommunications interconnection model for the exchange of IP based traffic between customers of separate mobile and fixed operators as well as other types of service provider, via IP based Network-to-Network Interface. IPX is developed by the GSM Association.

Hurricane Electric is a global Internet service provider offering internet transit, tools, and network applications, as well as data center colocation and hosting services at two locations in Fremont, California, where the company is based.

Transworld Associates is a Tier-1 provider based in Pakistan. It is a joint-venture between Orastar Limited and the Oman based OMZEST Group. Transworld owns and operates the 1,300 km submarine communications cable named TW1 that links Pakistan to the United Arab Emirates and Oman.

Net bias is the counter-principle to net neutrality, which indicates differentiation or discrimination of price and the quality of content or applications on the Internet by ISPs. Similar terms include data discrimination, digital redlining, and network management.

<span class="mw-page-title-main">GTT Communications</span> Tier 1 Internet service provider

GTT Communications, Inc. (GTT) is a managed network and security services provider to global organizations, headquartered in McLean, Virginia. GTT operates a global Tier 1 IP network, and its communication services include voice and video, Internet, Voice over Internet Protocol (VoIP), Wide Area Networking, SD-WAN, Secure Access Service Edge (SASE), Network Security, Cloud Security, Multi-Protocol Label Switching (MPLS), and Managed and Professional Services. GTT serves global enterprise customers across North and South America, Europe, and Asia Pacific.


  1. Norton, William B. "What is a Tier 2 ISP?". DrPeering. Retrieved 15 September 2023.
  2. "AS Rank: A ranking of the largest Autonomous Systems (AS) in the Internet". asrank.caida.org.
  3. Visualizing Internet Topology at a Macroscopic Scale April 2005
  4. "CAIDA AS Rank". 2016-01-25. Retrieved 2015-07-29.
  5. "Cogent - Google - HE Fun". 2016-03-09.