Q: What is iSCSI?
A: The iSCSI standard is a protocol that resides on top of TCP and is designed to transport SCSI commands and data across an IP network, most commonly across Ethernet.

Q: Who developed the iSCSI standard?
A: The iSCSI standard was developed by a working group under the Internet Engineering Task Force (IETF). The most current version is 1.0.

Q: What does an iSCSI device look like to the operating system?
A: From a software perspective, an iSCSI device appears as a locally attached SCSI drive. The SCSI commands are intercepted and directed to the iSCSI layer. They are encapsulated, then sent out as TCP packets. At the far end, the reverse happens so a SCSI command arrives at the device.

Q: What is iSCSI good for?
A: There are many applications for iSCSI. It is especially useful for lower-cost connection of second- and third-tier servers into existing Fibre Channel Storage Area Networks (SANs) for block access to storage. Many applications do not require the high level of performance that Fibre Channel provides, and iSCSI performance is often "good enough." These applications might include file services, DHCP services, mail services, or some development applications.

Q: Do regular Ethernet switches work with iSCSI?
A: Yes. From the network perspective, iSCSI traffic looks like another IP packet. Existing Ethernet switches and IP routers work transparently.

Q: What type of iSCSI functionality is supported by the Brocade FC4-16IP iSCSI Blade?
A: This product adds iSCSI-FC gateway functionality to the Brocade 48000 Director, translating iSCSI traffic to Fibre Channel traffic. Using the Brocade FC4-16IP Blade, an iSCSI initiator (server) can access a Fibre Channel storage device. The iSCSI initiators can either be directly connected to the Ethernet ports on the iSCSI Blade or across an IP network. The Fibre Channel targets can be connected directly to the Fibre Channel ports on the Brocade FC4-16IP Blade, to the Fibre Channel ports on the Brocade 48000 Director, or across the Fibre Channel fabric.

Q: Can all switch ports terminate iSCSI sessions?
A: The Gigabit Ethernet ports on the Brocade FC4-16IP can terminate iSCSI sessions.

Q: Is iSCSI bundled with the base Brocade Fabric OS firmware or do I have to buy it separately?
A: iSCSI is provided free of charge in Fabric OS versions 5.2 and higher. Only the proper hardware (the Brocade FC4-16IP Blade) is required.

Q: Can typical Brocade tools be used for iSCSI management?
A: Fabric Manager, Web Tools, and the Brocade command line interface can be used for iSCSI management, including configuring iSCSI LUN mapping/masking.

Q: Does the Brocade FC4-16IP iSCSI Blade support the "SendTargets" command?
A: Yes.

Q: Does the Brocade FC4-16IP Blade leverage the Internet Storage Name Server (iSNS)?
A: Yes, the Brocade implementation leverages iSNS to simplify discovery and management of iSCSI and Fibre Channel end nodes in the network.

Q: How many iSCSI initiators are supported per port?
A: At first release, 64 initiators are supported per Gigabit Ethernet port.

Q: What iSCSI Error Recovery Levels are supported?
A: The Brocade FC4-16IP iSCSI Blade supports an Error Recovery Level of 0, recovery by session restart, as mandated by the iSCSI specification.

Q: Can an Ethernet port be configured for running FCIP and iSCSI traffic concurrently?
A: No. FCIP and iSCSI are deployed for different uses, and have different requirements. Brocade focuses on optimizing the specific hardware platform from a cost/performance perspective for the use case. Brocade has developed the Brocade FR4-18i Blade and the Brocade 7500 Switch to be the industry’s top-performing FCIP solution, and the Brocade FC4-16IP iSCSI Blade is optimized for highly scalable iSCSI support.

Q: Can the Brocade Fast Write capability in Fabric OS 5.2 be used with iSCSI?
A: Fast Write improves the performance of write operations by prompting the initiator of a storage session to keep the long-distance WAN pipe full of data. Fast Write is applicable only to FCIP sessions and is not relevant to iSCSI sessions. However, iSCSI has provisions for unsolicited data, which provides similar benefits. These aspects of the iSCSI specification are fully supported by the Brocade FC4-16IP iSCSI Blade.

Q: What kind of iSCSI performance can I expect from the Brocade FC4-16IP iSCSI Blade?
A: The Brocade FC4-16IP iSCSI Blade performs the iSCSI-FC gateway functionality at wire-speed (1 Gbit/sec). Note that the performance could be impacted by the capabilities of the iSCSI initiator and the attached Fibre Channel storage; in addition, the end nodes need to be wire-speed capable. Also, over-subscription on the IP network could impact performance.

Q: Does the Brocade FC4-16IP iSCSI Blade support LUN mapping/masking in conjunction with iSCSI initiators? If so, do I have to always use it?
A: Yes, it supports LUN mapping/masking for iSCSI initiators. These capabilities are available natively on the Fibre Channel target and the capabilities provided by the Brocade FC4-16IP iSCSI Blade can be used independently.

Q: Can I use E_Port in conjunction with iSCSI? Are there any caveats with this configuration?
A: Yes, E_Port can be used in conjunction with iSCSI to provide access between iSCSI devices and Fibre Channel devices in a Fibre Channel fabric.

Q: What type/level of iSCSI authentication is supported by the SAN internetworking switch?
A: DH-CHAP-based authentication is supported.