Streaming Media Supplement sa2150 and sa2250

22
Chapter 3 Understanding Media-IXT and RealNetworks
PNA should be avoided where possible. For reference, here is the scenario for forward, transparent proxy
caching, which is supported for PNA:
Figure 3-2. Forward, transparent proxy caching for RealNetworks (beginning)
Figure 3-3. Forward, transparent proxy caching for RealNetworks (concluded)
Origin
Rea l Ser v er
with
hlcac e p u g i n
L4 Sw it ch
Media-IXT
Client browser with RealPlayer
udp
5
accounting
6
tcp
7
port
9231
8
4
rtsp
RealPlayer sends t he redirected RTSP request to M edia-IXT on port 9231.
Media-IXT opensan accounting connection to the origin RealServer.
Thisclient isallowed access, so
Media-IXT opensa TCP connection to the origin RealServer.
Media-IXT determineswhether the requested content isin cache, and whether it isfresh.
The content isin cache and is fresh, so Media-IXT doesnot need to pull the content from
the origin server.
Media-IXT st reams content to RealPlayer.
4
5
6
7
8
P
L
U
G
I
N
Me ia-IXTd
Origin
Rea l Ser v er
with
hlcac e p u g in
L4 Sw i t ch
Client browser with RealPlayer
udp
5
accounting
6
tcp
7
port
9231
8
4
rtsp
RealPlayer sends t he redirected RTSP request to Media-IXT on port 9231.
Media-IXT opensan accounting connection to the origin RealServer.
Thisclient isallowed access, so
Media-IXT opensa TCP connection to the origin RealServer.
Media-IXT determineswhether the requested content isin cache, and whether it isfresh.
The content isin cache and isfresh, so Media-IXT does not need to pull the content from
the origin server.
Media-IXT st reams content t o RealPlayer.
4
5
6
7
8
Me ia-IXTd
P
L
U
G
I
N