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

XPath OS 7.4.x administrator guide 77
6 Using the iSCSI Gateway Service
The HP iSCSI Gateway Service facilitates communication between TCP/IP networks and Fibre Channel
SANs. It displays iSCSI gateway configuration information across multiple MP Routers. The iSCSI Gateway
Service is discussed in the following sections:
• Summary of configuration steps, next
• Configuring an iSCSI portal, page 78
• Configuring iSCSI gateway zones, page 79
• Configuring CHAP, page 80
• Administering iSCSI configurations, page 80
• Working with the WWN mapping table, page 82
• Enabling and disabling failover, page 82
XPath OS supports eight iSCSI sessions per port and 96 sessions per MP Router.
Figure 15 shows a simple application of the iSCSI Gateway Service, in which an iSCSI initiator
communicates with a Fibre Channel target through an iSCSI gateway. The gateway projects the initiator
onto the Fibre Channel SAN, and projects the target onto the TCP/IP network. The iSCSI gateway converts
iSCSI to FCP FC-4 protocol and maps iSCSI fully qualified names (IQNs) from TCP/IP to Fibre Channel in
a process called IQN-to-WWN mapping.
The projection of an iSCSI initiator into the Fibre Channel SAN creates a proxy Fibre Channel initiator; the
projection of a Fibre Channel target to the TCP/IP network creates a proxy iSCSI target. The proxy initiator
fully participates in access controls, such as zoning, and the proxy target responds like a regular iSCSI
target.
Figure 15 Simple application of the iSCSI Gateway Service
TCP/IP servers can use iSCSI arrays that are directly connected to the IP network; Fibre Channel servers
connected to the SAN can use Fibre Channel arrays.
An iSCSI portal cannot be used for any other purpose, but other ports on the same MP Router can be used
for any other HP multi-protocol routing service.
You can achieve access control by configuring iSCSI initiators and the iSCSI portal to use iSCSI challenge
handshaking authentication protocol (CHAP). CHAP allows remote servers and clients to exchange
authentication credentials securely.
If you define iSCSI portals on multiple MP Routers, iSCSI drivers that support failover can fail over from one
portal to another if the connection to the first portal is lost.
iSCSI initiator
Fibre Channel
target
Proxy iSCSI
target
Proxy Fibre
Channel initiator
iSCSI gateway
IP
network
Fibre Channel SAN