Akamai AANP Whitepaper
Akamai AANP Whitepaper
Akamai AANP Whitepaper
Executive Summary
The Akamai Accelerated Network Partner (AANP) program is a way for ISPs
and other network providers to reduce upstream bandwidth costs and free up
peering capacity while providing high speed Web delivery to their end users.
The document provides an overview of the AANP program, including details on
how Akamais services work in general and within the AANP context.
Table of Contents
Akamai Overview
Background and Network Snapshot ................................................. pg 1
Akamai Overview
Background and Network Snapshot
Founded in 1998, Akamai Technologies (NASDAQ: AKAM) is the global leader in Internet content
delivery and application acceleration. By delivering content requests from servers located near
the end user, the Akamai Platform significantly increases end user performance while decreasing
network infrastructure and bandwidth usage.
The Akamai Platform currently handles
approximately 20% of the worlds Web traffic,
delivering content for the vast majority of top
media, entertainment, retail, and technology
Web sites and companies.
In a decade of testing for thousands of customers, Akamai has consistently seen performance
improvements ranging from 2 times to over 10 times for content cached and delivered from its
servers at the edge of the Internet, compared to delivering the content from centralized servers.
While performance benefits are significant even for users requesting content originating within
their own country, the increase in speed can be truly dramatic for internationally-based content,
as connectivity and latency delays have a greater effect over great distances. Akamai helps
eliminate performance barriers so that end users across the globe enjoy a responsive Web
experience, no matter where in the world the content is hosted.
Figure 1.
Akamai offers speeds
nearly 4 times faster
than the origin server
for the file download
shown here.
Because Akamai delivers approximately 20% of the worlds Web traffic, including content from
many of the Webs most popular sites, AANPs are able to deliver a superior end user experience
for a significant portion of requested content. This, in turn, allows the AANP to increase
subscriber satisfaction and differentiate themselves competitively.
Increased peering capacity and reduced upstream bandwidth expenses. Because the
most popular content delivered by Akamai is cached on the Akamai servers, upstream bandwidth
requirements and transit costs are reduced for AANPs, as caching greatly reduces the need to
repeatedly retrieve the content from the origin server.1 Reducing upstream traffic also eases
pressure from the AANPs peering points, enabling the existing peering points to effectively serve
more end users and allowing the AANP to postpone potentially costly equipment upgrades.
Furthermore, the bandwidth reduction, performance, and reliability advantages of Akamai
become even more significant as the Web moves toward richer, more dynamic sites with
increasingly heavier media such videos and downloads.
Figure 2.
Akamais Network
Partner Portal displays
near real-time reports
comparing traffic served
to end users (red) with
traffic pulled from
upstream providers
(green).
Note that unlike general-purposes caches, however, content freshness for Akamai-delivered is completely
controlled by the content provider / origin Web site, ensuring that end users receive exactly the version of
content that was intended. This is discussed further in the caching section of this whitepaper.
Standard 4-post, 19 racks with 10x32 holes preferred (most other rack types can be used,
if necessary)
2 rack units per server, plus 1-3 rack units per cluster for switches
Because they have the most familiarity with their own network, the AANP typically performs the
hardware installation and IP address assignment. Akamai provides detailed instructions as well
as on-call technical support for the initial deployment process.
Akamai servers are deployed outside the AANPs firewall and should be treated like any other
Web server on the Internet. No changes to the AANPs network configuration are needed.
Once the machines are racked, powered, and assigned IP addresses, Akamai handles the software
installation, system integration, and server monitoring remotely. Akamai monitors its entire
network 24x7 from several locations worldwide, including its main Network Operations Command
Center (NOCC) in Cambridge, MA. Akamai generally performs maintenance remotely as well, but
may occasionally require Hands and Eyes assistance from the AANP. Akamais NOCC is also
available around the clock to answer AANP questions or troubleshoot issues as they arise.
How Akamais DNS system works, including how Akamai handles mapping the AANPs
subscribers to Akamai edge servers.
How Akamais edge server caching is controlled to ensure freshness and maximize
performance.
2
Server and network hardware specifications may change with time and with the traffic requirements for each
specific AANP.
BGP feeds from networks, along with a comprehensive database of IP mapping information,
to determine the closest clusters to the user, both geographically and topologically
Contract terms, including rules that ensure that an AANPs end usersand only the AANPs
end usersare directed to clusters within the AANP
Once the user is mapped to an optimal Akamai cluster, a cluster-specific low-level map
chooses an optimal server for the user, based on factors like real-time server health and
capacity, as well as the content each server already has cached. This process is illustrated on
the next page.
Note that among other things, Akamais dynamic DNS automatically performs sophisticated load
balancing both within each Akamai cluster and between Akamai clusters. AANPs do not need to
provide any additional load balancing mechanisms.
Users Web browser requests www.example.com (a URL for content that is delivered via
Akamai).
2.
Users local DNS name server resolves www.example.com and receives a CNAME
redirect to edgesuite.net, an Akamai domain:
Users local name server resolves edgesuite.net and is sent to an Akamai Top Level
DNS (TLDNS) server, which uses Akamais high-level map to determine which cluster to
send the user to. The TLDNS directs the requester to a specific cluster through
delegation to a cluster-specific Akamai Low Level DNS (LLDNS) server.
4.
Users name server then sends a request to the LLDNS, which uses Akamais
continuously updated low-level map to return the IP address of an optimal Akamai
server within that cluster to handle the request.
5.
Users name server thus receives the IP address of a dynamically chosen, nearby,
optimal Akamai server to deliver www.example.com to the end user. The name server
returns this IP address to the browser
6.
The browser requests and receives www.example.com content from the local Akamai
server.
The AANPs subscribers are served content from the optimal Akamai cluster within the AANP
as often as possible, and
End users who are not AANP customers are not served content from the AANP.
In order to do this, Akamai needs to know which IP addresses are part of the AANP network. In
particular, Akamai needs to know the IP addresses of the nameservers that the AANPs subscribers
are using. This is most effectively provided through BGP feeds that keep Akamai updated on which
prefixes should be served by the Akamai cluster within the AANPs network. Communicating this
information ensures that users are mapped the appropriate clusters for optimal performance. This
topic is discussed in greater detail in a separate document entitled BGP with Akamai.
Not all content served from all clusters. Although Akamai has deployed servers in over 1500
data centers around the world, not all content will be served from every cluster. This is due to a
number of factors.
First, different types of content require different types of servers, and not every cluster will have
all types of servers deployed. The table below lists the four main types of Akamai content servers.
Server Type
Content Type
Protocols
HTTP Delivery
Web Sites
HTTP
Downloads
HTTP
same as above
SSL (over
HTTP)
RTSP or
HTTP
.flv
RTMP or
HTTP
SSL Delivery3
(Akamai Linux + custom
applications)
Windows Streaming
(Windows/Windows Media
Server + custom apps)
Flash Streaming
(Windows/Flash
Communication Server +
custom applications)
All standard deployments have HTTP Delivery servers. Windows Streaming, Flash Streaming, and
SSL Delivery servers are installed in larger deployments, depending on end user traffic volume.
Additionally, Akamai may restrict certain customer content to subsets of the Akamai network to
meet specific customer requirements. For example, customers may have restrictions on which
countries may host or serve their content.
3
Note: Every Akamai server can and does serve SSL content; however only SSL Delivery
servers are able to do so with customer-owned SSL certificates.
Akamais high-level maps maintain information about which content can be served from which
clusters and ensure that end users are only mapped to clusters that can serve the particular type
of content they have requested. If an AANPs subscriber requests a piece of content that cannot
be served from the AANPs Akamai cluster(s), then the subscriber will be mapped to a nearby
Akamai cluster outside the AANP network for that particular request.
AANP clusters unavailable. As part of the Akamai networks fault tolerant design, an AANPs
subscribers will automatically be mapped to alternative clusters in the case that the AANP clusters
are unreachable. This may happen if the cluster is offline for routine maintenance or if a
temporary outage occurs for any reason. Additionally, if the cluster is out of server or bandwidth
capacity, some of the traffic will be served from elsewhere.
Akamai continuously monitors its clusters, and when it detects that an AANP cluster is unavailable
or over capacity, the high-level map will automatically update to direct users to the next best
cluster, based on current Internet performance conditions, etc. This process is transparent to end
users, who will continue to receive their requested content (from the next-best location) without
interruption. When the AANP cluster comes back online or has spare capacity, users will
automatically be directed back to the AANP network for their Akamai content.
Cacheability
High/long
30 days to indefinite
Moderate
1 to 7+ days
Moderate to Low
30 minutes to 2 hours
News or scores
Low
1-5 minutes
Stock quote
Very Low
15 seconds
N/A
Because Akamai customers are able to easily optimize cacheability, they maximize their origin
traffic offload and end user performance benefits. This in turn means AANPs enjoy the very same
benefits: a high degree of bandwidth reduction and end user performance improvement.
Voice: +1-617-444-3007
Fax: +1-617-444-3685
E-mail: noc@akamai.com
The Akamai Network Support group serves as an escalation point for any AANP issues. Issues
may be escalated to them from the NOCC, and they can also be contacted directly to answer
questions about server performance, server operation within the AANP network, or for other
network or relationship-related questions.
The Network Support group currently operates during business hours
(9 AM to 5 PM Eastern Time) at:
Voice: +1-617-444-0089
US toll-free: 1-888-421-1003
E-mail: netsupport-tix@akamai.com
Scheduled Maintenance
In the event that the AANP needs to schedule maintenance during which the servers would lose
connectivity or power, the NOCC should be contacted with at least 24 hours notice.
Voice: +1-617-444-0089
US toll-free: 1-888-421-1003
E-mail: netsupport-tix@akamai.com
Reproduction in whole or in part in any form or medium without express written permission is prohibited.
Akamai, the Akamai wave logo are registered trademarks. Other trademarks contained herein are the property
of their respective owners.Akamai believes that the information in this publication is accurate as of its
publication date; such information is subject to change without notice.