## Advanced SAN extension features 

The 24/10-Port SAN Extension Module supports hardware-based FCIP compression to increase the effective WAN bandwidth of SAN extension solutions. The module can deliver compression ratios in the range of 4:1 - 5:1 over a wide variety of data sources. 

The SAN extension module supports AES 256 IPsec encryption for secure transmission of sensitive data over extended distances. Hardware enablement of IPsec helps ensure line-rate throughput. Together, hardware-based compression and hardware-based encryption provide a high-performance, highly secure SAN extension capability. 

Additionally, the SAN extension module supports FCIP write acceleration, a feature that can significantly improve application performance when storage traffic is extended across long distances. When FCIP write acceleration is enabled, WAN throughput is optimized by reducing the latency of command acknowledgments. 

## VSANs 

Well suited for efficient, secure SAN consolidation, ANSI T11-standard VSANs enable more efficient storage network utilization by creating hardware-based isolated environments with a single physical SAN fabric or switch. Each VSAN can be zoned as a typical SAN and maintained with its own fabric services for greater scalability and resilience. VSANs allow the cost of SAN infrastructure to be shared among more users, while helping ensure segregation of traffic and retaining independent control of configuration on a VSAN-by-VSAN basis. 

## Integrated SAN routing 

In another step toward deployment of efficient, cost-effective, consolidated storage networks, the 24/10- Port SAN Extension Module supports IVR, the industry’s first and most efficient routing function for Fibre Channel. IVR allows selective transfer of data between specific initiators and targets on different VSANs while maintaining isolation of control traffic within each VSAN. With IVR, data can transit VSAN boundaries while maintaining control-plane isolation, thereby maintaining fabric stability and availability. IVR eliminates the need for external routing appliances, greatly increasing routing scalability while delivering line-rate routing performance, simplifying management, and eliminating the challenges associated with maintaining separate systems. IVR reduces the total cost of SAN ownership. 

## Advanced traffic management 

The advanced traffic management capabilities integrated into the 24/10-Port SAN Extension Module simplify deployment and optimization of large-scale fabrics: 

Virtual output queuing: Helps ensure line-rate performance on each port, independent of traffic  pattern, by eliminating head-of-line blocking. 

Port channels: Allow users to aggregate up to 16 FCIP ISLs into a single logical bundle, providing  optimized bandwidth utilization across all links. The bundle can consist of any speed-matched ports from any module in the chassis, helping ensure that the bundle can remain active even in the event of a module failure. 

Fabric Shortest Path First (FSPF)-based multipathing: Provides the intelligence to load-balance  traffic across up to 16 equal-cost paths and, in the event of a switch failure, dynamically reroute traffic. 

QoS: Can be used to manage bandwidth and control latency to prioritize critical traffic.  

Shaper: Rate limits the WAN bandwidth according to the maximum bandwidth configured for the FCIP  tunnel. 

