Introduction - Scalable Continuous Media Streaming Systems - page 22

Begin

Determine Resources
Requirement

Determine Resources
Available

Sufficient
Resources?

Yes No

Admit Client Reject/Queue Client

Figure 1.20 Flow chart for a general admission control procedure

Media Server
Admission Control

Media Client
Admission Control Network Admission Control

NIC NIC

Buffer NNetwork Buffer

Decoder Display

Media
Data

Media Server Media Client

Figure 1.21 Providing end-to-end performance guarantee requires performance guarantee to be avail-
able in all the intermediate system components

Now let us examine the media streaming system in more detail as shown in Figure 1.21. The
first observation is that only performing admission control in the network may not be sufficient
to provide performance guarantee. In particular, the media server as well as the media client
also has finite resources available for media streaming. Moreover, at the media server these
resources are often shared among multiple concurrent media streams and possibly with other
services as well. At the client, on the other hand, there are likely multiple applications running
(in a multi-tasked operating system) that compete for the resources such as processor time,
memory, or even network bandwidth.
Therefore, if we want to provide absolute end-to-end performance guarantee it will be
necessary to investigate all the intermediate system components from the data storage all the