Content Delivery Network - AbsoluteAstronomy.com

A content delivery network or content distribution network (CDN) is a system of computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

s containing copies of data

Data (computing)

In computer science, data is information in a form suitable for use with a computer. Data is often distinguished from programs. A program is a sequence of instructions that detail a task for the computer to perform...

placed at various nodes

Node (networking)

In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...

of a network

Computer network

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

.

When properly designed and implemented, a CDN can improve access to the data it cache

Cache

In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...

s by increasing access bandwidth

Bandwidth (computing)

In computer networking and computer science, bandwidth, network bandwidth, data bandwidth, or digital bandwidth is a measure of available or consumed data communication resources expressed in bits/second or multiples of it .Note that in textbooks on wireless communications, modem data transmission,...

and redundancy

Redundancy (engineering)

In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe....

and reducing access latency. Data content types often cached in CDNs include web objects (text, graphics, URLs and scripts), downloadable objects (media files, software, documents), applications, live streaming media, and database queries.

CDN benefits

The capacity sum of strategically placed servers can be higher than the network backbone capacity. This can result in an impressive increase in the number of concurrent users. For instance, when there is a 10 Gbit/s network backbone and 200 Gbit/s central server capacity, only 10 Gbit/s can be delivered. But when 10 servers are moved to 10 edge locations, total capacity can be 10×10 Gbit/s.

Strategically placed edge

Edge computing

Edge computing provides application processing load balancing capacity to corporate and other large-scale web servers. It is like an application cache, where the cache is in the Internet itself. Static web-sites being cached on mirror sites is not a new concept...

servers decrease the load on interconnects, public peers

Peering

In computer networking, peering is a voluntary interconnection of administratively separate Internet networks for the purpose of exchanging traffic between the customers of each network. The pure definition of peering is settlement-free or "sender keeps all," meaning that neither party pays the...

, private peers and backbones

Internet backbone

The Internet backbone refers to the principal data routes between large, strategically interconnected networks and core routers in the Internet...

, freeing up capacity and lowering delivery costs. It uses the same principle as above. Instead of loading all traffic on a backbone or peer link, a CDN can offload these by redirecting traffic to edge servers.

CDNs generally deliver content over TCP

Transmission Control Protocol

The Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...

and UDP

User Datagram Protocol

The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...

connections. TCP throughput over a network is affected by both latency

Latency (engineering)

Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. Latencies may have different meaning in different contexts.-Packet-switched networks:...

and packet loss

Packet loss

Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is distinguished as one of the three main error types encountered in digital communications; the other two being bit error and spurious packets caused due to noise.-...

. In order to reduce both of these parameters, CDNs traditionally place servers as close to the edge networks that users are on as possible. Theoretically the closer the content the faster the delivery, although network distance may not be the factor that leads to best performance. End users will likely experience less jitter

Jitter

Jitter is the undesired deviation from true periodicity of an assumed periodic signal in electronics and telecommunications, often in relation to a reference clock source. Jitter may be observed in characteristics such as the frequency of successive pulses, the signal amplitude, or phase of...

, fewer network peaks and surges, and improved stream quality—especially in remote areas. The increased reliability allows a CDN operator to deliver HD

High-definition video

High-definition video or HD video refers to any video system of higher resolution than standard-definition video, and most commonly involves display resolutions of 1,280×720 pixels or 1,920×1,080 pixels...

quality content with high Quality of Service

Quality of service

The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...

, low costs and low network load. Some providers also utilize TCP acceleration

TCP Acceleration

TCP acceleration is the name of a series of techniques for achieving better throughput on an Internet connection than standard TCP achieves, without modifying the end applications...

technology to further boost CDN’s performance and end-user experiences.

CDNs can dynamically distribute assets to strategically placed redundant core, fallback and edge servers. CDNs can have automatic server availability sensing with instant user redirection. A CDN can offer 100% availability

Availability

In telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...

, even with large power, network or hardware outages.

CDN technologies give more control of asset delivery and network load. They can optimize capacity per customer, provide views of real-time

Real time business intelligence

Real-time business intelligence is the process of delivering information about business operations as they occur.In this context, real-time means a range from milliseconds to a few seconds after the business event has occurred...

load and statistics, reveal which assets are popular, show active regions and report exact viewing details to the customers. These usage details are an important feature that a CDN provider must provide, since the usage logs are no longer available at the content source server after it has been plugged into the CDN, because the connections of end-users are now served by the CDN edges instead of the content source.

ASP versus on-net

Most CDNs are operated as an application service provider

Application service provider

An application service provider is a business that provides computer-based services to customers over a network. Software offered using an ASP model is also sometimes called On-demand software or software as a service ....

(ASP) on the Internet, although an increasing number of internet network owners, such as AT&T and Level3, have built their own CDN to improve on-net content delivery and to generate revenues from content customers. Some develop internal CDN software; others use commercially available software.

Technology

CDN nodes are usually deployed in multiple locations, often over multiple backbones

Internet backbone

The Internet backbone refers to the principal data routes between large, strategically interconnected networks and core routers in the Internet...

. These nodes cooperate with each other to satisfy requests for content by end users, transparently moving content to optimize the delivery process. Optimization can take the form of reducing bandwidth

Bandwidth (computing)

costs, improving end-user performance (reducing page load times and improving user experience), or increasing global availability of content.

The number of nodes and servers making up a CDN varies, depending on the architecture, some reaching thousands of nodes with tens of thousands of servers on many remote PoPs

Point of presence

A point of presence is an artificial demarcation point or interface point between communications entities. It may include a meet-me-room.In the US, this term became important during the court-ordered breakup of the Bell Telephone system...

. Others build a global network and have a small number of geographical PoPs.

Requests for content are typically algorithmically directed to nodes that are optimal in some way. When optimizing for performance, locations that are best for serving content to the user may be chosen. This may be measured by choosing locations that are the fewest hops, the fewest number of network seconds away from the requesting client, or the highest availability in terms of server performance (both current and historical), so as to optimize delivery across local networks. When optimizing for cost, locations that are least expensive may be chosen instead.

In an optimal scenario, these two goals tend to align, as servers that are close to the end user at the edge of the network may have an advantage in performance or cost. The Edge Network is grown outward from the origin/s by further acquiring (via purchase, peering, or exchange) co-locations facilities, bandwidth and servers.

Content networking techniques

The Internet was designed according to the end-to-end principle

End-to-end principle

The end-to-end principle is a classic design principle of computer networking which states that application specific functions ought to reside in the end hosts of a network rather than in intermediary nodes, provided they can be implemented "completely and correctly" in the end hosts...

. This principle keeps the core network relatively simple and moves the intelligence as much as possible to the network end-points: the hosts and clients. As a result the core network is specialized, simplified, and optimized to only forward data packets.

Content Delivery Networks augment the end-to-end transport network by distributing on it a variety of intelligent applications employing techniques designed to optimize content delivery. The resulting tightly integrated overlay uses web caching, server-load balancing, request routing, and content services.
These techniques are briefly described below.

Web cache

Web cache

A web cache is a mechanism for the temporary storage of web documents, such as HTML pages and images, to reduce bandwidth usage, server load, and perceived lag...

s store popular content on servers that have the greatest demand for the content requested. These shared network appliances reduce bandwidth requirements, reduce server load, and improve the client response times for content stored in the cache.

Server-load balancing

Load balancing (computing)

Load balancing is a computer networking methodology to distribute workload across multiple computers or a computer cluster, network links, central processing units, disk drives, or other resources, to achieve optimal resource utilization, maximize throughput, minimize response time, and avoid...

uses one or more techniques including service based (global load balancing) or hardware based, i.e. layer 4–7 switches

Multilayer switch

A multilayer switch is a computer networking device that switches on OSI layer 2 like an ordinary network switch and provides extra functions on higher OSI layers.- Layer 3 Switching :...

, also known as a web switch, content switch, or multilayer switch to share traffic among a number of servers or web caches. Here the switch is assigned a single virtual IP address

IP address

An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...

. Traffic arriving at the switch is then directed to one of the real web servers attached to the switch. This has the advantage of balancing load, increasing total capacity, improving scalability, and providing increased reliability by redistributing the load of a failed web server and providing server health checks.

A content cluster or service node can be formed using a layer 4–7 switch to balance load across a number of servers or a number of web caches within the network.

Request routing directs client requests to the content source best able to serve the request. This may involve directing a client request to the service node that is closest to the client, or to the one with the most capacity. A variety of algorithms are used to route the request. These include Global Server Load Balancing, DNS-based request routing, Dynamic metafile generation, HTML rewriting, and anycast

Anycast

Anycast is a network addressing and routing methodology in which datagrams from a single sender are routed to the topologically nearest node in a group of potential receivers all identified by the same destination address.-Addressing methodologies:...

ing. Proximity—choosing the closest service node—is estimated using a variety of techniques including reactive probing, proactive probing, and connection monitoring.

CDNs use a variety of methods of content delivery including, but not limited to, manual asset copying, active web caches, and global hardware load balancers.

Content service protocols

Several protocol suites are designed to provide access to a wide variety of content services distributed throughout a content network. The Internet Content Adaptation Protocol

Internet Content Adaptation Protocol

The Internet Content Adaptation Protocol is a lightweight HTTP-like protocol specified in RFC 3507 which is used to extend transparent proxy servers, thereby freeing up resources and standardizing the way in which new features are implemented. ICAP is generally used to implement virus scanning,...

(ICAP) was developed in the late 1990s to provide an open standard for connecting application servers. A more recently defined and robust solution is provided by the Open Pluggable Edge Services (OPES) protocol. This architecture defines OPES service applications that can reside on the OPES processor itself or be executed remotely on a Callout Server. Edge Side Includes

Edge Side Includes

Edge Side Includes or ESI is a small markup language for edge level dynamic web content assembly. The purpose of ESI is to tackle the problem of web infrastructure scaling. It is an application of edge computing....

or ESI is a small markup language for edge level dynamic web content assembly. It is fairly common for websites to have generated content. It could be because of changing content like catalogs or forums, or because of personalization. This creates a problem for caching systems. To overcome this problem a group of companies created ESI.

Peer-to-peer CDNs

Although peer-to-peer

Peer-to-peer

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...

(P2P) is not traditional CDN technology, it is increasingly used to deliver content to end users. P2P claims low cost and efficient distribution. Even though P2P actually generates more traffic than traditional client-server CDNs for the edge provider (because a peer also uploads data instead of just downloading it) it's welcomed by parties running content delivery/distribution services. The real strength of P2P shows when one has to distribute data in high demand, like the latest episode of a television show or some sort of software patch/update in short period of time. One of the advantages of this is that the more people who download the (same) data, the more efficient P2P is for the provider, slashing the cost of the transit fees that a CDN provider has to pay to their upstream IP transit providers.

On the other hand, the “long tail

Long tail

Long tail may refer to:*The Long Tail, a consumer demographic in business*Power law's long tail, a statistics term describing certain kinds of distribution*Long-tail boat, a type of watercraft native to Southeast Asia...

” type material does not benefit much from P2P delivery schema, since, to gain advantage over traditional distribution models, a P2P-enabled CDN must force storing (caching) data on peers—something that is usually not desired by users and which is rarely enabled.

Contrary to popular belief, P2P is not limited to low-bandwidth audio-video signal distribution. There is no technical boundary, built-in inefficiency, or flaw-by-design in peer-to-peer technology to prevent distribution of full HD audio+video signal at, for example, 8 Mbit/s. It's just environmental factors, like low (upload) bandwidth or inadequate computing power in CE

Consumer electronics

Consumer electronics are electronic equipment intended for everyday use, most often in entertainment, communications and office productivity. Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver...

devices, that prevent HD material being publicly available in P2P CDNs. (Low bandwidth problems also apply to traditional CDN, though.)

There are some concerns about lack of Quality of Service control over P2P distribution, but these are being addressed by the P2P-Next consortium. Other concerns include security (e.g. modification of content to include malware) and DRM

Digital rights management

Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

Emergence of telco CDNs

The rapid growth of streaming video traffic uses large capital expenditures by broadband providers in order to meet this demand and to retain subscribers by delivering a sufficiently good quality of experience

Quality of experience

Quality of experience , some times also known as quality of user experience, is a subjective measure of a customer's experiences with a service...

.

To address this, telecommunications service provider

Telecommunications Service Provider

A telecommunications service provider or TSP is a type of communications service provider that has traditionally provided telephone and similar services...

s (TSPs) have begun to launch their own content delivery networks as a means to lessen the demands on the network backbone and to reduce infrastructure investments.

Telco CDN advantages

Because they own the networks over which video content is transmitted, telco CDNs have advantages over traditional CDNs.

They own the last mile

Last mile

The "last mile" or "last kilometer" is the final leg of delivering connectivity from a communications provider to a customer. The phrase is therefore often used by the telecommunications and cable television industries. The actual distance of this leg may be considerably more than a mile,...

and can deliver content closer to the end user because it can be cached deep in their networks. This deep caching minimizes the distance that video data travels over the general Internet and delivers it more quickly and reliably.

Telco CDNs also have a built-in cost advantage since traditional CDNs must lease bandwidth from them and build the operator’s margin into their own cost structures.

Federated CDNs

In June of 2011, StreamingMedia.com reported that a group of TSPs had founded an Operator Carrier Exchange (OCX) to interconnect their networks and compete more directly against large traditional CDNs like Akamai and Limelight Networks, which have extensive points of presence (POPs) worldwide. This way, telcos are building a Federated CDN offer, much more interesting for a content provider willing to deliver its content to the agregated audience of this federation.

It is likely that in a near future, other telco CDN federations will be created. They will grow by enrolment of new telco joining the federation and bringing network presence and Internet subscribers base to the existing ones.

edns-client-subnet EDNS0 option

In August 2011, a global consortium of leading Internet service providers led by Google announced their official implementation of the edns-client-subnet IETF Internet-Draft, which is intended to accurately localize DNS resolution responses. The initiative involves a limited number of leading DNS and CDN service providers. With the edns-client-subnet EDNS0 option, the recursive DNS servers of CDNs will utilize the IP address of the original client when resolving DNS requests. Traditional CDNs rely on the IP address of the DNS resolver instead of that of the client when resolving DNS requests, which can pose latency problem if the DNS resolver of the client’s ISP is far from the location of the client.

Free CDNs

Cloudflare
CloudFlare
CloudFlare is a content delivery network and distributed Domain Name Server service aimed at enhancing website performance and speed and providing security. CloudFlare offers both free and paid services. CloudFlare gained media attention after providing security to LulzSec's website...
coBlitz (a subproject of CoDeeN
Codeen
CoDeeN is a proxy server system created at Princeton University in 2003 and deployed for general use on PlanetLab.It operates as per the following:# Users set their internet caches to a nearby high bandwidth proxy that participates in the system....

)
Coral Content Distribution Network
Coral Content Distribution Network
The Coral Content Distribution Network, sometimes called Coral Cache or Coral, is a free peer-to-peer content distribution network designed and operated by Michael Freedman...
FreeCast
FreeCast
FreeCast is a free software application which allows peer-to-peer streaming, sometimes called peercasting. It makes possible an audio or video stream broadcast to a large number of listeners from a simple DSL connection....
MediaBlog
MediaBlog
MediaBlog is software that distributes almost all kinds of streams on P2P network based on VLC player. The main idea of MediaBlog come from PeerCast and BitTorrent....
PeerCast
PeerCast
PeerCast is an open source streaming media multicast tool. PeerCast uses peer-to-peer technology to minimize the necessary upload bandwidth for the original multicaster.The website of PeerCast appears to be abandoned since December 2007...
PPLive
PPLive
PPTV, developed by PPLive, is a leading online TV service offering both live streaming and video-on-demand of TV programs/shows, movies, drama, sports, news and entertainment video contents. The service is accessible either from its website or from client software installation...
PPStream
PPStream
PPS.tv is a Chinese peer-to-peer streaming video network software. Since the target users are on the Chinese mainland, there is no official English version, and the vast majority of channels are from East Asia, mostly Mainland China, Korea, Japan, Hong Kong, Taiwan and Singapore...
Xunlei
Xunlei
Xunlei is a download manager developed by Thunder Networking Technologies , supporting HTTP, FTP, EDonkey, BitTorrent protocols. , it was the most commonly used BitTorrent client worldwide....

Traditional commercial CDNs

Akamai Technologies
Akamai Technologies
Akamai Technologies, Inc. is an Internet content delivery network headquartered in Cambridge, Massachusetts, US.The company was founded in 1998 by then-MIT graduate student Daniel M. Lewin, and MIT Applied Mathematics professor Tom Leighton...
Amazon CloudFront
Amazon CloudFront
Amazon CloudFront is a content delivery network offered by Amazon Web Services. CloudFront operates on a pay-as-you-go basis. The service was launched in Beta on November 18, 2008....
CDNetworks
CDNetworks
CDNetworks founded in 2000, is a full service content delivery network , with increasing business in the United States.-Content delivery services:...
Cloudflare
CloudFlare
CloudFlare is a content delivery network and distributed Domain Name Server service aimed at enhancing website performance and speed and providing security. CloudFlare offers both free and paid services. CloudFlare gained media attention after providing security to LulzSec's website...
Cotendo
Cotendo
Cotendo, Inc. is a content delivery networkand an application delivery networkservice provider. The company's headquarters are in Sunnyvale, California, with research and development based in Netanya, Israel.- Mobile Acceleration Suite :...
EdgeCast Networks
EdgeCast Networks
EdgeCast Networks is a Los Angeles, CA, based content delivery network . The company was founded in 2006 and is funded by the venture arm of The Walt Disney Company, Steamboat Ventures. It has CDN reseller agreements with Deutsche Telekom, Global Crossing, Navisite, and The Planet...
Highwinds Network Group
Highwinds Network Group
Highwinds Network Group, Inc. is a content delivery, network and IP services business that offers a comprehensive suite of solutions, including CDN, IP transit, transport, peering, colocation, content storage and IP software. The company headquarters are located in Winter Park, Florida, U.S.A....
Internap
Internap
Founded in May 1996 in Seattle, Internap Network Services Corporation is a publicly traded company headquartered in Atlanta, Georgia that enables route-optimized delivery of content over the Internet. Internap’s business units include Internet Protocol , data center and Content Delivery Network ...
Level 3 Communications
Level 3 Communications
Level 3 Communications is a telecommunications and Internet service provider headquartered in Broomfield, Colorado.It operates a Tier 1 network. The company provides core transport, IP, voice, video and content delivery for most of the medium to large Internet carriers in North America and Europe...
Limelight Networks
Limelight Networks
Limelight Networks is a content delivery network service provider. The company is based in Tempe, Arizona, U.S.A., with offices in San Francisco, Seattle, New York, London, Paris, Frankfurt, and Tokyo. The company operates a global fiber-optic network that helps content publishers avoid sending...
Mirror Image Internet
Mirror Image Internet
Mirror Image Internet is a pure-play content delivery network that was founded in 1997. The company provides content delivery services for object caching, video on demand, live streaming, content storage. and an online video platform...
NetDNA
NetDNA
NetDNA is a Los Angeles, CA, based content delivery network and an application delivery network.The company was founded in October 2009 by Ben Neumann and Chris Ueland. Prior to NetDNA, Chris and Ben founded and operated Globat.com a shared-hosting company...
TV1.EU
Windows Azure CDN
Azure Services Platform
The Windows Azure Platform is a Microsoft cloud platform used to build, host and scale web applications through Microsoft data centers. Windows Azure Platform is thus classified as platform as a service and forms part of Microsoft's cloud computing strategy, along with their software as a service...
WINK Streaming

Telco CDNs

AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
Bharti Airtel
Bharti Airtel
Bharti Airtel Limited , commonly known as Airtel, is an Indian telecommunications company that operates in 20 countries across South Asia, Africa and the Channel Islands. It operates a GSM network in all countries, providing 2G or 3G services depending upon the country of operation...
Bell Canada
Bell Canada
Bell Canada is a major Canadian telecommunications company. Including its subsidiaries such as Bell Aliant, Northwestel, Télébec, and NorthernTel, it is the incumbent local exchange carrier for telephone and DSL Internet services in most of Canada east of Manitoba and in the northern territories,...
BT Group
BT Group
BT Group plc is a global telecommunications services company headquartered in London, United Kingdom. It is one of the largest telecommunications services companies in the world and has operations in more than 170 countries. Through its BT Global Services division it is a major supplier of...
Deutsche Telekom
Deutsche Telekom
Deutsche Telekom AG is a telecommunications company headquartered in Bonn, Germany. It is the largest telecommunications company in Europe....
Global Crossing
Global Crossing
Global Crossing Limited was a telecommunications company that provides computer networking services worldwide. It maintained a large backbone and offered transit and peering links, VPN, leased lines, audio and video conferencing, long distance telephone, managed services, dialup, colocation and...
KT
KT
-Science:* kT in Physics* Knot , a unit of velocity * Kardashev scale, method of measuring an advanced civilization's level of technological advancement...

(formerly Korea Telecom)
KPN
KPN
KPN is a Dutch landline and mobile telecommunications company, including both 2G and 3G mobile operations...
NTT
NTT
NTT may refer to:*Nippon Telegraph and Telephone, a telephone company that dominates the telecommunication market in Japan*Name That Tune, a now defunct game show*New Technology Telescope, a 3.6m telescope located at La Silla Observatory, Chile...
Orange Subsidiary of France Telecom
PCCW
PCCW
PCCW Limited is the holding company of HKT Group Holdings Limited, Hong Kong's premier telecommunications provider in the Information and Communications Technologies industry. PCCW also holds a majority interest in Pacific Century Premium Developments Limited...
Reliance Globalcom
SingTel
Tata Communications
Tata Communications
Tata Communications Limited ) is a telecommunications company located in Mumbai. They own a submarine cable network, a Tier-1 IP network, and also rent data center and colocation space. They operate India's largest data center in Pune...
TeliaSonera
TeliaSonera
TeliaSonera AB is the dominant telephone company and mobile network operator in Sweden and Finland. The company has operations in other countries in Northern, Eastern Europe, Central Asia and Spain, with a total of 150 million mobile customers...
Telecom Argentina
Telecom Argentina
Telecom Argentina is the major local telephone company for the northern part of Argentina, including the whole of the city of Buenos Aires...
Telecom Italia
Telecom Italia
Telecom Italia is the largest Italian telecommunications company, also active in the media and manufacturing industries. Now a private concern listed on the Borsa Italiana, it was founded in 1994 by the merger of several state-owned telecommunications companies, the most important of which was...
Telecom New Zealand
Telecom New Zealand
Telecom New Zealand is a New Zealand-wide communications service provider , providing fixed line telephone services, a mobile network, an internet service provider , a major ICT provider to NZ businesses , and a wholesale network infrastructure provider to other NZ CSPs...
Telefonica
Telefónica
Telefónica, S.A. is a Spanish broadband and telecommunications provider in Europe and Latin America. Operating globally, it is the third largest provider in the world...
Telstra
Telstra
Telstra Corporation Limited is an Australian telecommunications and media company, building and operating telecommunications networks and marketing voice, mobile, internet access and pay television products and services....
Telus
TELUS
Telus is a national telecommunications company in Canada that provides a wide range of telecommunications products and services including internet access, voice, entertainment, video, and satellite television. The company is based in Burnaby, British Columbia, part of Greater Vancouver...
Verizon

Commercial CDNs using P2P for delivery

BitTorrent, Inc.
Internap
Internap
Founded in May 1996 in Seattle, Internap Network Services Corporation is a publicly traded company headquartered in Atlanta, Georgia that enables route-optimized delivery of content over the Internet. Internap’s business units include Internet Protocol , data center and Content Delivery Network ...
Octoshape
Octoshape
Octoshape is a proprietary streaming media platform. It uses throughput optimization technology to deliver HD quality streams and to break through congestion in the last mile to provide more resilient delivery...
Pando Networks
Rawflow
Rawflow
RawFlow is a provider of live p2p streaming technology that enables internet broadcasting of audio and video. Rawflow was incorporated in 2002 by Mikkel Dissing, Daniel Franklin and Stephen Dicks. Its main office is in London, UK...