Internet small computer systems interface (iSCSI) distance acceleration device

• US 20070088795A1
• Filed: 09/29/2005
• Published: 04/19/2007
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Dunbar, J.
• Granted Patent: US 8,072,883 B2
• Time in Patent Office: Days
• US Class Current: 709/217
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]

Abstract

An Internet Small Computer Systems Interface (iSCSI) distance acceleration device accelerates data transfers between an iSCSI initiator and an iSCSI target over a network, such as the Internet or a wide area network (WAN). The acceleration device resides in a communication path between the iSCSI initiator and the iSCSI target. The acceleration device receives an iSCSI protocol data unit (PDU) targeted to the iSCSI target by the iSCSI initiator. The acceleration device forwards the iSCSI PDU over the network to the iSCSI target and transmits a response to the iSCSI PDU that anticipates a response to be generated by the iSCSI target upon receiving the iSCSI PDU.

Claims

1. A method of accelerating data transfers between an Internet Small Computer Systems Interface (iSCSI) initiator and an iSCSI target over a network, the method comprising:

receiving an iSCSI protocol data unit (PDU) by an acceleration device in a communication path between the iSCSI initiator and the iSCSI target;

forwarding, by the acceleration device, the iSCSI PDU over the network to the iSCSI target;

generating, by the acceleration device, a response to the iSCSI PDU that anticipates a response to be generated by the iSCSI target when the iSCSI target receives the iSCSI PDU; and

transmitting the response generated by the acceleration device to the iSCSI initiator.

2. The method of claim 1, wherein the iSCSI PDU encapsulates a Small Computer Systems Interface (SCSI) write command and the response generated by the acceleration device and transmitted to the iSCSI initiator encapsulates a SCSI Ready-to-Transmit message.

3. The method of claim 1, wherein the iSCSI PDU encapsulates data to be written at the iSCSI target, and the response generated by the acceleration device and transmitted to the iSCSI initiator encapsulates a SCSI status message.

4. The method of claim 1, wherein the iSCSI PDU encapsulates data to be written, and the response generated by the acceleration device and transmitted to the iSCSI initiator encapsulates a SCSI Ready-to-Transmit message.

5. The method of claim 1, further comprising the step of negotiating, between the acceleration device and the iSCSI initiator, a value for a given parameter.

6. The method of claim 5, wherein the acceleration device is a first acceleration device, and further comprising the step of negotiating, between a second acceleration device and the iSCSI target, a value for the same parameter negotiated between the first acceleration device and the iSCSI initiator.

7. The method of claim 6, wherein the iSCSI initiator issues iSCSI PDUs in accordance with the value for the given parameter negotiated with the first acceleration device and the iSCSI target replies with iSCSI PDUs in accordance with the value for the same parameter negotiated with the second acceleration device.

8. A network device for accelerating data transfers between an Internet Small Computer System Interface (iSCSI) initiator and an iSCSI target over a network, the method comprising:

a network interface receiving an iSCSI protocol data unit (PDU) from the ISCSI initiator and forwarding the iSCSI PDU over the network to the iSCSI target; and

means for generating a response to the ISCSI PDU that anticipates a response to be generated by the iSCSI target when the iSCSI target receives the iSCSI PDU, the generating means being in communication with the network interface for transmitting the response generated by the generating means to the iSCSI initiator.

9. The network element of claim 8, wherein the iSCSI PDU encapsulates a Small Computer Systems Interface (SCSI) write command and the response generated and transmitted to the iSCSI initiator encapsulates a SCSI Ready-to-Transmit message.

10. The network element of claim 8, wherein the iSCSI PDU encapsulates data to be written at the iSCSI target, and the response generated and transmitted to the iSCSI initiator encapsulates a SCSI status message indicating a successful writing of the data.

11. The network element of claim 8, wherein the iSCSI PDU encapsulates data to be written at the iSCSI target, and the response generated and transmitted to the iSCSI initiator encapsulates a SCSI Ready-to-Transmit message.

12. The network element of claim 8, further comprising an iSCSI device driver for negotiating an operational parameter with the iSCSI initiator.

13. A Internet Protocol (IP)-based network, comprising:

an Internet Small Computer Systems Interface (iSCSI) initiator sending an iSCSI protocol data unit (PDU) to a remote iSCSI target; and

an acceleration device in a communication path between the iSCSI initiator and the iSCSI target (1) receiving and forwarding the iSCSI PDU to the iSCSI target, (2) generating a response to the iSCSI PDU that anticipates a response to be generated by the iSCSI target when the iSCSI target receives the iSCSI PDU, and (3) transmitting the generated response to the iSCSI initiator.

14. The network of claim 13, wherein the iSCSI PDU encapsulates a Small Computer Systems Interface (SCSI) write command and the response generated and transmitted to the iSCSI initiator by the acceleration device encapsulates a SCSI Ready-to-Transmit message.

15. The network of claim 13, wherein the iSCSI PDU encapsulates data to be written at the iSCSI target, and the response generated and transmitted to the iSCSI initiator by the acceleration device encapsulates a SCSI status message indicating a successful writing of the data.

16. The network of claim 13, wherein the ISCSI PDU encapsulates data to be written at the iSCSI target, and the response generated and transmitted to the iSCSI initiator by the acceleration device encapsulates a SCSI Ready-to-Transmit message.

17. The network of claim 13, wherein the acceleration device is a first acceleration device, and further comprising a second acceleration device in communication with the first acceleration device and with the iSCSI target, the first acceleration device negotiating a value for a given parameter with the iSCSI initiator and the second acceleration device negotiating a value for the given parameter with the iSCSI target.

18. The network of claim 17, wherein the iSCSI initiator issues iSCSI PDUs in accordance with the value of the given parameter negotiated with the first acceleration device and the iSCSI target replies with iSCSI PDUs in accordance with the value of the given parameter negotiated with the second acceleration device.