HP Traffic Director sa7220 - Manual (Page 229)

C H A P T E R 6 e-Commerce Appliance Scenarios
217
Scenario 3:
Routing
Outbound Data
Away from the
SA8220 for
OPR You can configure the SA8220 to direct outbound data from the
fulfillment servers to bypass the SA8220. Most requests to servers
elicit a disproportionate amount of return data. Under some
circumstances, it is desirable to avoid routing such volumes of
content through the SA8220 as it returns to the client.
The SA8220’s Out of Path Return (OPR) mode allows you to remove
the SA8220 from the return path to the client. OPR sends requests to
a back-end server and allows the server to respond through its own
default gateway—thus bypassing the SA8220 altogether. OPR
requires that the server's loopback adapter be installed and configured
with the VIP as an alias, and that the server be programmed with a
default gateway address other than that of the SA8220.
The figure below shows the network diagram for scenario 3.
Network Diagram for Scenario 3
The next figure shows the data flow diagram for scenario 3.
Data Flow Diagram for Scenario 3
Client
Server
sa8220
Internet
Switch
Router
Client Broker S erver
S YN S YN
S YN/ACK
ACK ACK
Get UR L Get UR L
Data
Client Broker S erver
S YN S YN
S YN/ACK
ACK ACK
Get UR L Get UR L
Data