Content Delivery NetworksRod,
I run a small CDN oriented to audio/video distribution in Central Europe
region. You mentioned challenges that CDN are facing. There are several of
these:
1) Geographic load distribution
- in example, you have to have enough capacity in each distribution area that
is being potentionally served by your customers (media companies).
2) Computing power
- you have to have in each POP adequate computing power that allows you to use
full bandwidth available in that POP
3) Network capacity in each POP
- self explaining
4) Content moving
- you have to optimise internal data flows between POPs
5) User redirection
- You have to implement a scalable mechanisms that redirects users to the
closes POP. You can use application redirect (fast, but not so much scalable),
DNS redirect (scalable, but not so fast) or anycasting (this needs cooperation
with ISP).
6) Costs of the system
- Most CDNs are designed for peaking traffic, but load is more dynamic that in
traditional networks.
7) Play alone
There is almost no way for handover traffic to other CDN. No standards, no kinf
of interconnection agreement.
These points are only a rough overview, this ecosystem is developping and
challenges also depend on the starting conditions and region where you are
running you CDN.
Regards
Michal
----- Original Message -----
From: Rod Beck
To: Jason J. W. Williams ; Pekka Savola ; Robert Boyle
Cc: ALEJANDRO ESQUIVEL RODRIGUEZ ; nanog@merit.edu
Sent: Monday, August 06, 2007 23:10
Subject: Content Delivery Networks
Can anyone give a breakdown of the different kinds of content deliver
networks? For example, we have Akamai, which appears to be a pure Layer 3
network that is tailored to pushing relatively small files like web pages and
we have Lime Light Networks, which is a mix of Layer 1 and Layer 3, that
focuses on bigger files like video streams.
Any insights out there? And what are the major challenges in making scalable
content delivery networks?
Roderick S. Beck
Director of EMEA Sales
Hibernia Atlantic
1, Passage du Chantier, 75012 Paris
http://www.hiberniaatlantic.com
Wireless: 1-212-444-8829.
Landline: 33-1-4346-3209
AOL Messenger: GlobalBandwidth
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