Specifications

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Cisco Internet Streamer CDS 2.0-2.3 Software Configuration Guide
OL-13493-04
Chapter 1 Product Overview
Content Delivery System Architecture
is already stored locally is generally better than using content from the origin server; this is because the
Service Engine is typically closer to the requesting clients, and therefore network bandwidth to the origin
server is freed up.
Note When using Windows Media Server 2008 as the origin server, the source content type must be a playlist
or encoder type.
Live stream splitting can either be unicast or multicast, depending on the configuration, capabilities and
limitations of the network. The Windows Media Engine can receive and deliver Windows Media content
over IP multicast or unicast transmission in the following combinations:
• Unicast-In Multicast-Out
• Multicast-In Multicast-Out
• Unicast-In Unicast-Out
• Multicast-In Unicast-Out
Multicast-Out
The Windows Media Engine can act as a multicast station to deliver multicast streams to client devices.
The source of the stream can be multicast, unicast, or a local file. The station can be scheduled,
continuous, or play once. The content can be either live or rebroadcast. The Windows Media Engine
creates a Windows Media Station file (.nsc) that contains session information including the multicast IP
address, port, time-to-live (TTL), and so on. The client requests the .nsc file using HTTP. Once the file
is downloaded, the client parses it and sends an Internet Group Management Protocol (IGMP) join to
receive the multicast stream. A client can start and stop the stream, but cannot pause, fast-forward, or
rewind it. Multicast logging is a configurable option when setting up a multicast station. When multicast
logging is enabled, the Windows Media Player automatically collects and sends the statistics to the
multicast logging URL using the HTTP POST request method. The statistics collection is accomplished
either by a remote server or by the Service Engine itself.
Unicast-Out
The Windows Media Engine can act as a broadcast publishing point to deliver live streams,
prefetched/cached content, or content from dynamic ingest, to a requesting client. The source of the
stream can be multicast, unicast, or a local file. The Windows Media Engine can also perform live stream
splitting if more than one client requests the same content. The broadcast alias can be used to simulate
an experience similar to viewing a TV program even if the source of the stream is a Video On Demand
(VOD) file. A client can start and stop the stream but cannot pause, fast-forward, or rewind it. When a
broadcast alias is configured, a client makes a request to the Windows Media Engine, which is acting as
the Windows Media Server, and the Windows Media Engine checks to see whether the incoming stream
is present. If it is, the Windows Media Engine joins the stream and splits it to the new client. If the request
is the first client request for this stream, the Windows Media Engine sends the request to the origin server
and then serves it to the new client.
Authentication
The Windows Media Engine supports pass-through authentication. The following authentication
mechanisms are supported in pass-through mode:
• Anonymous
• NTLM
• Negotiate (Kerberos)
• Digest access authentication