In Information Security, we very frequently discuss the merits and challenges of Confidentiality and Integrity, but alas, Availability regularly takes the back seat...
In today's world of Dynamic Web Content, 24/7 uptime requirements, expectations of immediately downloads, and Customers that come to you from anywhere around the world, Content Deliver Networks are fast becoming a commodity service.
In our Enterprise Reference Architecture, we have all been taught to remove single points of failure. A High Availability (HA) environment consists of:
- Duplicate Network Switches with redundancy protocols
- Duplicate routers with redundancy protocols
- Duplicate firewalls with Heartbeat
- Redundant ISP circuits from two different providers
- redundant power supplies in all critical infrastructure, supplied from...
- Redundant street power from two separate grids
- Cluster or HA servers for critical systems such as Corporate Websites
These are all wonderful in a fair and decent world.... However... Where your Company's Image / Brand / Reputation meets your consumers, at your WebServers... there a higher level of risk, and a greater requirement for un-interrupted availability.
Enter the Content Delivery Networks (CDN)
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| (from http://ikuna.com) |
Content Delivery Networks provide a Geographically Disperse Web Service to replicate the content of your Web Servers, and provide that to your Customers in a highly available mode.
Most of the CDN providers use a subscription based approach with initial trial periods to evaluate their services. Almost all of them provide:
- HTTP acceleration for downloading of large files and website content
- Automatic and dynamic optimization of web page content
- Intelligent routing and load balancing
- Protection from distributed denial of service (DDoS) attacks
Introducing a CDN service to front your Critical Corporate websites not only makes sense, but will greatly enhance your Disaster Recovery and Business Continuity programme.
Content Delivery Network Providers:
(nowhere near a compete list, and with mergers and aquisitions... )
- Bell Canada: Content Delivery Network
- Telus Canada: Content Delivery Network (via Edgecast)
- Akamai Technologies
- Limelight Networks
- Amazon CloudFront
- AT&T's Digital Media Solutions
- BitTorrent Inc.
- CDNetworks
- Edgecast
- Ikuna
- PEER 1
- PeerCast
References:
- CDNPlanet: Content Delivery Networks
- Content delivery networks: A primer of CDN providers and technology
- Techtarget.com: content delivery network (CDN)
- How content delivery networks (CDNs) work
- http://www.quora.com/Content-Delivery-Networks/How-does-Akamai-CDN-work
- http://www.searchblog.asia/topics/seo/will-using-content-delivery-networks-affect-seo/
- http://serverfault.com/questions/46830/how-do-cdn-content-delivery-networks-server-work
- http://mae.ucdavis.edu/dsouza/Classes/MAE298-S09/sc421.pdf
- Updated List Of Vendors In The Content Delivery and Transparent Caching Markets
- To Speed Up The Web, EdgeCast Has Added Google PageSpeed Technology To Its CDN
