HP StorageWorks XPath OS 7.4.X Administrator Guide (AA-RVHDD-TE, February 2006)

12 Introducing XPath OS features

FCIP Tunneling Service

The FCIP Tunneling Service enables you to extend the Fibre Channel SAN over distances that would be

impractical or too expensive with native Fibre Channel links. The service employs a proprietary transport

protocol that allows the transparent interconnection of geographically distributed SANs through an

IP-based network.

XPath OS supports FCIP between two MP Routers only, not between an MP Router and another switch

model.

FCIP enables Fibre Channel frames to tunnel through IP networks by dividing frames, encapsulating the

result in IP packets when they enter the tunnel, and then reconstructing them as they leave the tunnel.

Figure 1 illustrates a simple FCIP tunneling configuration.

Figure 1 Simple FCIP tunneling configuration

Chapter 5, “Using the FCIP Tunneling Service,” further describes these concepts and provides procedures

for configuring FCIP.

iSCSI Gateway Service

The iSCSI is a protocol that defines the processes for transferring block storage over TCP/IP networks by

encapsulating SCSI commands into TCP and transporting them over the network via IP. The iSCSI Gateway

Service enables organizations to integrate low-cost Ethernet-connected servers into HP StorageWorks Fibre

Channel SANs by bridging the iSCSI protocol to the Fibre Channel protocol. This capability allows iSCSI

servers to leverage shared SAN resources, improving asset utilization and enabling new applications. This

integration greatly reduces the cost of connecting servers to centrally managed storage and helps provide

a cost-effective solution to introduce utility computing into the enterprise.

Chapter 6, “Using the iSCSI Gateway Service,” further describes these concepts and provides procedures

for configuring an MP Router for use as an iSCSI gateway.

Combining services

Using FCIP tunneling along with FC-FC routing enables you to keep two fabrics separate instead than

merging them into a single fabric, which would permit any-to-any connectivity among all devices. For

example, you can build a configuration similar to that shown in Figure 2, in which FCIP tunnelling and an

IP network provide transport between two MP Routers.

iSCSI cannot run concurrently with FCIP tunneling on the same port, but both can be used concurrently on

the same switch without restrictions.

If you combine iSCSI and FC or iSCSI and FCR and FCIP, the iSCSI initiators can access FC storage only

within the backbone fabric.

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