Issue No. 22
The Key Is High Port/Lane Ratio
Security Appliances are going beyond web
application firewall support and providing new
forms of data compression to increase WAN
throughput, providing new caching techniques to
minimize latency and terminating SSL connections
to offload servers. These devices often have only one
WAN side and one LAN side connection. Yet,
internally, with the multitude of data processing
present, they require a way to connect several
processing boards together.
Figure 2 shows a PEX 8508 connecting several
dedicated processing boards which allow parallel
processing of data and an uplink to the host
controller. Here the boards represent application
layer firewall support including dynamic access
control lists and active signature recognition, SSL
encryption, data compression, and caching. The host
controller handles exception packets and enumerates,
configures and manages the system.
Cache
CPU
Added Advantage for PLX
In addition, the PEX 8508 includes many optional
PCI Express capabilities such as Hot Swap
controllers on every port. This switch supports all of
the Hot Swap usage models including a manually
operated retention latch, Attention Buttons, and
Electromechanical Interlock. This allows individual
processing boards to be replaced without a system
and thereby WAN link shutdown.
Additional PLX Advantages
♦
Superior PCI Express expertise and support
♦
Extensive line of compatible PCI Express
Switches and Bridges
♦
Plug-fest certified PCI Express Compliance for
full interoperability
Design Tools & Documentation:
On PLX Public ToolBox:
♦
Data book, Reference Design Kit, BSDL and
HSPICE Models, Product Brief
Contact Information
PLX Technology, Inc.
870 Maude Ave.
Sunnyvale, CA 94085 USA
Tel: 1-800-759-3735
Tel: 1-408-774-9060
Fax: 1-408-774-2169
Applications Support: Local FAE
Product Marketing:
John Gudmundson
jgudmundson@plxtech.com
Web Site: www.plxtech.com
© 2005 PLX Technology, Inc. All rights reserved. PLX and the PLX logo are
registered trademarks of PLX Technology, Inc. ExpressLane, PowerDrive and
the PowerDrive logo are trademarks of PLX Technology, Inc., which may be
registered in some jurisdiction. All other product names that appear in this
material are for identification purposes only and are acknowledged to be
trademarks or registered trademarks of their respective companies. Information
supplied by PLX is believed to be accurate and reliable, but PLX Technology,
Inc. assumes no responsibility for any errors that may appear in this material.
PLX Technology, Inc. reserves the right, without notice, to make changes in
product design or specification.
8508-SIL-EA-1.0
Compression
Root Complex
NT Port
SSL
Router
Firewall
VPN
Application
Firewall
PEX 8508
Switch
LAN
Security Appliance
WAN
Figure 2
The PEX 8508 is an excellent fit as it has the right
amount of ports and lanes for the fan-out needs. The
root complex typically provides a x4-lane PCIe
interface that matches the switch’s upstream port. As
the WAN link is typically under one gigabit per
second, the x1 lane ports of the switch provide
ample throughput. Root complex ICs may have two
x4 lane links. So for systems with redundancy, this
architecture can be extended with backup added
processing boards for failover. Or additional boards
could be added for supplementary functionality, dual
WAN links or multiple LAN ports.
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November 2005, ExApp22_8508_Security_Apps.doc
PLX [ PLX TECHNOLOGY ]
