What is protocol? Explain Interface Protocol used for host to storage communications?
➢ A protocol enables communication between the host and storage.
➢ Protocols are implemented using interface devices (or controllers) at both source and destination.
➢ The popular interface protocols used for host to storage communications are: i. Integrated Device Electronics/Advanced Technology Attachment (IDE/ATA) ii. Small Computer System Interface (SCSI), iii. Fibre Channel (FC) iv. Internet Protocol (IP)
IDE/ATA and Serial ATA:
➢ IDE/ATA is a popular interface protocol standard used for connecting storage devices, such as disk drives and CD-ROM drives.
➢ This protocol supports parallel transmission and therefore is also known as Parallel ATA (PATA) or simply ATA.
➢ IDE/ATA has a variety of standards and names.
➢ The Ultra DMA/133 version of ATA supports a throughput of 133 MB per second.
➢ In a master-slave configuration, an ATA interface supports two storage devices per connector.
➢ If performance of the drive is important, sharing a port between two devices is not recommended.
➢ The serial version of this protocol is known as Serial ATA (SATA) and supports single bit serial transmission.
➢ High performance and low cost SATA has replaced PATA in newer systems.
➢ SATA revision 3.0 provides a data transfer rate up to 6 Gb/s.
SCSI and Serial SCSI:
➢ SCSI has emerged as a preferred connectivity protocol in high-end computers.
➢ This protocol supports parallel transmission and offers improved performance, scalability, and compatibility compared to ATA.
➢ The high cost associated with SCSI limits its popularity among home or personal desktop users.
➢ SCSI supports up to 16 devices on a single bus and provides data transfer rates up to 640 MB/s.
➢ Serial attached SCSI (SAS) is a point-to-point serial protocol that provides an alternative to parallel SCSI.
➢ A new version of serial SCSI (SAS 2.0) supports a data transfer rate upto 6Gb/s.
Fibre Channel (FC):
➢ Fibre Channel is a widely used protocol for high-speed communication to the storage device.
➢ Fibre Channel interface provides gigabit network speed.
➢ It provides a serial data transmission that operates over copper wire and optical fiber.
➢ The latest version of the FC interface (16FC) allows transmission of data up to 16 Gb/s. Internet Protocol (IP):
➢ IP is a network protocol that has been traditionally used for host-to-host traffic.
➢ With the emergence of new technologies, an IP network has become a viable option for hostto-storage communication.
➢ IP offers several advantages: ✓ cost ✓ maturity ✓ enables organizations to leverage their existing IP-based network.
➢ iSCSI and FCIP protocols are common examples that leverage IP for host-to-storage communication.
➢ Protocols are implemented using interface devices (or controllers) at both source and destination.
➢ The popular interface protocols used for host to storage communications are: i. Integrated Device Electronics/Advanced Technology Attachment (IDE/ATA) ii. Small Computer System Interface (SCSI), iii. Fibre Channel (FC) iv. Internet Protocol (IP)
IDE/ATA and Serial ATA:
➢ IDE/ATA is a popular interface protocol standard used for connecting storage devices, such as disk drives and CD-ROM drives.
➢ This protocol supports parallel transmission and therefore is also known as Parallel ATA (PATA) or simply ATA.
➢ IDE/ATA has a variety of standards and names.
➢ The Ultra DMA/133 version of ATA supports a throughput of 133 MB per second.
➢ In a master-slave configuration, an ATA interface supports two storage devices per connector.
➢ If performance of the drive is important, sharing a port between two devices is not recommended.
➢ The serial version of this protocol is known as Serial ATA (SATA) and supports single bit serial transmission.
➢ High performance and low cost SATA has replaced PATA in newer systems.
➢ SATA revision 3.0 provides a data transfer rate up to 6 Gb/s.
SCSI and Serial SCSI:
➢ SCSI has emerged as a preferred connectivity protocol in high-end computers.
➢ This protocol supports parallel transmission and offers improved performance, scalability, and compatibility compared to ATA.
➢ The high cost associated with SCSI limits its popularity among home or personal desktop users.
➢ SCSI supports up to 16 devices on a single bus and provides data transfer rates up to 640 MB/s.
➢ Serial attached SCSI (SAS) is a point-to-point serial protocol that provides an alternative to parallel SCSI.
➢ A new version of serial SCSI (SAS 2.0) supports a data transfer rate upto 6Gb/s.
Fibre Channel (FC):
➢ Fibre Channel is a widely used protocol for high-speed communication to the storage device.
➢ Fibre Channel interface provides gigabit network speed.
➢ It provides a serial data transmission that operates over copper wire and optical fiber.
➢ The latest version of the FC interface (16FC) allows transmission of data up to 16 Gb/s. Internet Protocol (IP):
➢ IP is a network protocol that has been traditionally used for host-to-host traffic.
➢ With the emergence of new technologies, an IP network has become a viable option for hostto-storage communication.
➢ IP offers several advantages: ✓ cost ✓ maturity ✓ enables organizations to leverage their existing IP-based network.
➢ iSCSI and FCIP protocols are common examples that leverage IP for host-to-storage communication.