Cisco CSS 11501 Datasheet page 3

Modularity for Investment Protection
The Cisco CSS 11500 offers the greatest flexibility and scalability of any midrange Layer 4-7 switch. Through its
modular design, the Cisco CSS 11500 will meet your functional requirements today while providing for expansion
for tomorrow's needs. The Cisco CSS 11500 Session Accelerator Module is a cost-effective way to add performance
for flow setup and flow forwarding. A selection of input/output (I/O) modules not only gives you the choice of port
densities of Fast or Gigabit Ethernet, but also boosts flow performance. Optional memory upgrades increase the
number of simultaneous flows supported. PCMCIA Flash memory and hard disks are supported.
Local and Global Load Balancing
By supporting the latest advances in local and global load balancing, the Cisco CSS 11500 Series Switch not only
dramatically increases site availability—greatly improving user response time and retention—but also optimally
utilizes site resources, thereby decreasing the cost to serve end users.
The Cisco CSS 11500 learns where specific content resides, either locally or remotely, and dynamically selects the
best Web server or cache for specific content requests.
Local server selection is based on server load and application response time, as well as traditional least connection
and round-robin algorithms. Any application that uses standard TCP or User Datagram Protocol (UDP) protocols
can also be load balanced, including firewalls, mail, news, chat, and Lightweight Directory Access Protocol (LDAP).
The Cisco CSS 11500 also provides a complete solution for building and provisioning Internet-scale global content
distribution and delivery. Whereas local load-balancing features determine the best device within a data center, global
load-balancing functions choose the best data center in the Internet to service requests.
The Cisco CSS 11500 performs comprehensive resource verification before routing user requests, ensuring that they
are directed to the location that has the best response time and the least load for the requested content. Cisco supports
global load balancing through redirection based on both Domain Name System (DNS) and HTTP. The DNS
mechanism is fast and scalable; the HTTP method provides the highest degree of control.
Site and System Security
The Cisco CSS 11500 with Cisco WebNS Software ensures high levels of security without compromising site
performance. The Cisco CSS 11500 provides stateful, content-based access control, and supports security policies
based on any combination of source address, destination address, protocol, TCP port, or URL. The Cisco CSS 11500
monitors start-to-finish Web transaction activity and guards against denial-of-service (DoS) attacks such as SYN
floods, ping floods, "smurfs," and any other undesirable connection attempts. Wire-speed Network Address
Translation (NAT) protects real server IP addresses.
For additional security, the Cisco CSS 11500 intelligently directs traffic across multiple firewalls. By load balancing
firewalls, the Cisco CSS 11500 eliminates performance bottlenecks and single points of failure that result in system
downtime, a situation that can close off the connection to the network and disrupt e-commerce purchases or other
mission-critical transactions.
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