Streaming Media Supplement sa2150 and sa2250

Chapter 2 Media-IXT Deployment Scenarios

Understanding CDS preload

Content Delivery Suite

™

(CDS) is an application from Inktomi that permits administrators to replicate and

synchronize the delivery of all types of content across network servers and caches. CDS provides a means to

preload streaming media files and to make scheduled updates to the cache.

Authenticated CDS Servers can preload streaming media content into Media-IXT caches on the same network.

Preloading Traffic Server caches ensures that data is available at the edge of the network even before the client

requests it.

CDS preloads the content of URLs in series; if there are multiple caches, CDS preloads the caches in series.

Because media files tend to be large, this can be a time-consuming process. Once Media-IXT has been told to

preload particular content, it pulls that content from the origin server. So, CDS preload is a pull-based, as

opposed to a push-based, preload model.

CDS preload is only supported for RealNetworks content in Media-IXT 4.x.

Understanding authentication

Media-IXT 4.x supports two kinds of authentication: proxy authentication through to origin server, and LDAP

authentication. Proxy authentication through to origin server is present by default; to choose LDAP

authentication you must configure Media-IXT as described later in this manual.

Proxy authentication.

Proxy authentication through to origin server requires the origin server to issue a

challenge to a user who requests content, and determine whether to permit that user access or not.

LDAP authentication.

LDAP authentication does not involve the origin server; rather, Traffic Server Media–

IXT issues the challenge to the user, and connects to a designated LDAP database server, which determines the

validity of the user’s request. LDAP stands for Lightweight Directory Access Protocol.

Understanding proxy authentication through to origin server

An origin server may respond to a client request for content with an authentication challenge. Media-IXT passes

the authentication challenge through to the client without interference.

Media-IXT 4.x only supports this feature for content streamed with RealNetworks or WMT software.

This feature acts no differently for forward and reverse proxy, non-hierarchical, and hierarchical deployments

of Media-IXT.

Understanding LDAP authentication

In some deployments, users wishing to view content through Media-IXT must pass an authentication challenge

validated against an LDAP server.

Media-IXT 4.x only supports this feature where Media-IXT is configured for forward proxy, and only for

content streamed with RealNetworks software.

LDAP authentication works for both on-demand and live content.

Media-IXT must be configured to use LDAP. See Chapter 7‚ Configuring Media-IXT for RealNetworks for

details.

Understanding

firewalls

Firewalls typically fall into three categories:

NOTE For more information about CDS, see:

http://www.inktomi.com