Cisco Systems OL-12518-01 CPE Selection-Choosing between the 9216i, Multiprotocol Services Module

Chapter 4 FCIP over IP/MPLS Core

Using FCIP Tape Acceleration

Multiprotocol Services Module

The Cisco MDS 9000 Family 14/2-port Multiprotocol Services Module delivers the intelligence and advanced features required to make multilayer SANs a reality, by integrating in a single module the functions offered by the Cisco 16-Port Fibre Channel Switching Module and the Cisco IP Storage Services Module. The Cisco MDS 9000 Family 14/2-port Multiprotocol Services Module doubles both the Fibre Channel and port density of the Cisco MDS 9216i when used in the switch expansion slot.

Cisco 7200

The Cisco PA-FC-1G PAM, when used with a Cisco 7200 VXR series router or a Cisco 7401 router, provides a method for extending the performance of a SAN by providing Fibre Channel bridge port (B port) functionality. The PA-FC-1G is based on an FCIP ASIC that provides the Fibre Channel and FCIP functions for the port adapter. The FCIP ASIC provides direct memory access (DMA) for complete packets across the Peripheral Component Interconnect (PCI) bus.

When designing for maximum SAN performance with the PA-FC-1G, consider the effect of the PCI bus structure on the Cisco 7200 series router. The Cisco 7200 series router with the NSE-1 or NPE-400 network processors provides the following two internal PCI buses:

•PCI bus mb1 controls slot 0 (the I/O controller) and PA slots 1, 3, and 5

•PCI bus mb2 controls PA slots 2, 4, and 6.

Each PCI bus has a raw throughput of approximately 1.6 Gbps. This effectively limits the PA-FC-1G to a theoretical limit of approximately 500 Mbps if there are two other port adapters on the same PCI bus. Additionally, when data is fast-switched between port adapters, it must traverse to and from the 7200 system memory over the PCI bus. If the data is transmitted between two port adapters on the same bus, the data must traverse the PCI bus twice, effectively reducing the performance of the data path by three-fourths.

Also consider the PCI bandwidth utilization of the other modules installed in the Cisco 7200 router, including port adaptor modules (PAMs), service adapters (SAs), and the I/O controller. Each module has an assigned bandwidth value that reflects the maximum PCI bus utilization of that module. Each PCI bus (mb1 and mb2) has a maximum recommended bandwidth point value of 600 points per bus. When configuring the Cisco 7200 VXR series router, you must also take these bandwidth points into consideration when placing the modules into the chassis. For more information, see the Cisco 7200 Series Port Adapter Installation Requirements documentation at the following URL:

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_configuration_guide_chapter091 86a008014cf5c.html

CPE Selection—Choosing between the 9216i and 7200

The Cisco MDS 9216i is used when the line rate is a requirement. The Cisco MDS 9216i also supports VSANs and it is optimized for TCP operations. For typical new installations where line rate is a requirement, then the Cisco MDS 9216i with IPS is the correct option.

Most SMBs may already have invested in the Cisco 7200 to transport their data. In these scenarios, installing a Fibre Channel port adaptor on the Cisco 7200 provides a cost effective solution. This solution with the VAM/VAM2 modules supports compression and encryption. The Cisco 7200-based solution is ideal if the traffic demand on the WAN is less than OC-3 speed.

	Data Center High Availability Clusters Design Guide
4-12	OL-12518-01