Secure Computing SSL Scanner Manuale Utente Scaricare il pdf (Pagina 17)

Dedicated CDN Application Example

Core

Backbone

Users

Web Servers

Blue Coat

Server Accelerator

With SSL

Cacheable Objects

Retrieved from

Nearest Servers

Intranet

Firewall

London

Data Center

Miami

Data Center

New York

Data Center

HTML

Request

to Server

Los Angeles

Data Center

Web Server Cluster

www.example.com

Global Server

Load Balancer

Figure 14 – Dedicated Content Distribution Network Application Example

A Content Distribution Network (CDN) is deﬁned as a network infrastructure where the content is stored in geographical

locations, rather than in one central spot. When enterprise or content providers distribute their content throughout their global

infrastructure, it is considered a dedicated CDN. Figure 14 shows a dedicated CDN for the site www.example.com. In this

application, Blue Coat ProxySGs are used to front-end the www.example.com origin servers, and they are also located

in geographical locations throughout the Internet, typically in various data centers. As requests come into the example.com

web site, a Layer 4-Global Server Load Balancer (GSLB) automatically sends the browser requests to the appropriate

Blue Coat secure proxy. For example, it directs requests from Los Angeles to the L.A. ProxySG; it sends requests from

Europe to the London ProxySG, etc. The GSLB performs health checks on the proxies to ensure that requests are not sent

to overloaded appliances. The primary beneﬁt is end user (customer) response time and availability by getting data closer

to them; additional beneﬁts include bandwidth gain, origin server ofﬂoad, surge protection, replicated content and reduced

management requirements.

The SSL tunnel termination capabilities of the Blue Coat ProxySG allow the distributed content to be either cleartext objects, or

SSL-encrypted objects. Before the Blue Coat ProxySG, CDNs could not be built to support the distribution of encrypted content.

Technology Primer: Secure Sockets Layer (SSL)

1 2 ... 12 13 14 15 16 17 18 19 20 21 22

Nessun commento

Secure Computing SSL Scanner Manuale Utente Pagina 17