Fibre Channel Intro

Fibre Channel is a set of standards for connecting storage devices in a fabric network. The Fibre Channel standard identifies a protocol and a collection of physical interfaces for managing computer peripheral components. This standard’s key purpose is managing large numbers of storage devices. Fibre Channel uses serial interfaces working at symbol rates from 133MB/s up to 4.25Gb/s. Optical as well as electrical signals are supported. Fibre Channel supports data transmission rates of 100MBps. It also allows 126 devices to be connected on a single network.

The channels are full duplex, offering full bandwidth and double the channel rate. Topologies comprise of point-to-point, shared loop, and switched. Fibre Channel is associated with numerous protocol layers, the most well-liked are the storage protocols SCSI (FCP) and ESCON (FICON). Fibre Channel is the primary technology used to deploy Storage Area Networks (SANs).

Fibre Channel Topologies

Fibre Channel supports three fabric topologies:

• Fabric
• Loop
• Point-to-Point

Fibre Channel Physical Connectivity

Fibre Channel supports connectivity over fiber optic cabling or copper wiring.

Fibre Channel devices using fiber optic cabling use two unidirectional fiber optic cables for each connection. One fiber optic cable is used for transmitting, the other for receiving. Fibre channel over fiber optic cable supports cable distances of up to 10Km.

Fibre Channel devices that communicate over copper cabling are limited to distances of 30m.

Fibre Channel Devices

Fibre Channel Devices include:

• Host Bust Adapters (HBA’s)
• Fibre Channel Hubs
• Fibre Channel Switches

Fibre Channel Ports

Fibre Channel uses a shorthand terminology to describe different types of connections to the Fibre Channel network.

Fibre Channel uses the term “ports” and defines seven different types of ports:

Short Name	Descriptive Name	Device Type	Port Function
N-port	Network Port	Nodes	Node port used to connect a node to a Fibre Channel switch
F-port	Fabric Port	Switches	Switch port used to connect the Fibre Channel fabric to a node
L-port	Loop Port	Nodes	Node port used to connect a node to a Fibre Channel loop
NL-port	Network + Loop Port	Nodes	Node port that connects to both loops and switches
FL-port	Fabric + Loop Port	Switches	Switch port that connects to both loops and switches
E-port	Extender Port	Switches	Used to cascade Fibre Channel switches together
G-port	General Port	Switches	General purpose port that can be configured to emulate other port types

Fibre Channel Standards

The American National Standards Institute (ANSI) defines the Fibre Channel standards.

FCAP (Fibre Channel Authentication Protocol)

FCAP is an optional authentication mechanism employed between any two devices or entities on a Fibre Channel network using certificates or optional keys.

FCPAP (Fibre Channel Password Authentication Protocol)

FCPAP is an optional password based authentication and key exchange protocol that is utilized in Fibre Channel Storage Area Networks (SANs).

FCPAP is used to mutually authenticate Fibre Channel ports to each other. This includes E_Ports, N_Ports, and Domain Controllers.

ESP over Fibre Channel

ESP (Encapsulating Security Payload) is an Internet standard for the authentication and encryption of IP packets. ESP is defined in RFC 2406: IP Encapsulating Security Payload (ESP).

FC-SP (Fibre Channel – Security Protocol)

Fibre Channel – Security Protocol (FC-SP) is a security protocol for Fibre Channel Protocol (FCP) and fiber connectivity (Ficon).

FC-SP is a project of Technical Committee T11 of the International Committee for Information Technology Standards (INCITS).

FC-SP is a security framework that includes protocols to enhance Fibre Channel security in several areas, including Fibre Channel device authentication, cryptographically secure key exchange, and cryptographically secure communication between Fibre Channel devices.

FC-SP is focused on protecting data in transit throughout the Fibre Channel network. FC-SP does not address the security of data that is stored on the Fibre Channel network.

ESP is widely deployed in IP networks and has been adapted for use in Fibre Channel networks. The IETF iSCSI proposal specifies ESP link authentication and optional encryption.

ESP over Fibre Channel is focused on protecting data in transit throughout the Fibre Channel network. ESP over Fibre Channel does not address the security of data that is stored on the Fibre Channel network.

SLAP (Switch Link Authentication Protocol)

SLAP is an authentication method for Fibre Channel switches that utilizes digital certificates to authenticate switch ports.

SLAP was designed to prevent the unauthorized addition of switches into a Fibre Channel network.

DH-CHAP

DH-CHAP (Diffie Hellman – Challenge Handshake Authentication Protocol) is a forthcoming Internet Standard for the authentication of devices connecting to a Fibre Channel switch.

DH-CHAP is a secure key-exchange authentication protocol that supports both switch-to-switch and host-to-switch authentication.

DH-CHAP supports MD5 and SHA-1 algorithm-based authentication.

Attacks against FCP

Attacks against FCP (Fibre Channel Protocol) include:

• Node Name / Port Name spoofing at Port Login time
• Source Port ID spoofing on data-less FCP commands
• Snooping and spoofing on FC-AL
• Snooping and Spoofing after Fabric reconfiguration
• Denial of Service attacks can be made in User mode

A Neurochip That Can Communicate With Brain

The University of Calgary, Faculty of Medicine scientists who proved it is possible to cultivate a network of brain cells that reconnect on a silicon chip—or the brain on a microchip—have developed new technology that monitors brain cell activity at a resolution never achieved before.

Developed with the National Research Council Canada (NRC), the new silicon chips are also simpler to use, which will help future understanding of how brain cells work under normal conditions and permit drug discoveries for a variety of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s.

Naweed Syed's lab cultivated brain cells on a microchip.

The new technology from the lab of Naweed Syed, in collaboration with the NRC, is published online this month in the journal, Biomedical Devices.

“This technical breakthrough means we can track subtle changes in brain activity at the level of ion channels and synaptic potentials, which are also the most suitable target sites for drug development in neurodegenerative diseases and neuropsychological disorders,” says Syed, professor and head of the Department of Cell Biology and Anatomy, member of the Hotchkiss Brain Institute and advisor to the Vice President Research on Biomedical Engineering Initiative of the U of C.

The new neurochips are also automated, meaning that anyone can learn to place individual brain cells on them. Previously it took years of training to learn how to record ion channel activity from brain cells, and it was only possible to monitor one or two cells simultaneously. Now, larger networks of cells can be placed on a chip and observed in minute detail, allowing the analysis of several brain cells networking and performing automatic, large-scale drug screening for various brain dysfunctions.

This new technology has the potential to help scientists in a variety of fields and on a variety of research projects. Gerald Zamponi, professor and head of the Department of Physiology and Pharmacology, and member of the Hotchkiss Brain Institute, says, “This technology can likely be scaled up such that it will become a novel tool for medium throughput drug screening, in addition to its usefulness for basic biomedical research”.

An Artificial Leaf Invented Which Can Solve Power Crisis

An important step toward realizing the dream of an inexpensive and simple “artificial leaf,” a device to harness solar energy by splitting water molecules, has been accomplished by two separate teams of researchers at MIT

Scientists have created the world’s first practical artificial leaf that can turn sunlight and water into energy, which they claim could pave the way for a cheaper source of power.

A team at Massachusetts Institute of Technology (MIT) says that the artificial leaf from silicon, electronics and various catalysts which spur chemical reactions within the device, can use sunlight to break water into hydrogen and oxygen which can then be used to create electricity in a separate fuel cell.

“A practical artificial leaf has been one of the Holy Grails of science for decades. We believe we have done it. And placed in a gallon of water and left in sun, these artificial leaves could provide a home in the developing world with basic electricity for a day,” Daniel Nocera, who led the team, said.

He added: “Our goal is to make each home its own power station. One can envision villages in India and Africa not long from now purchasing an affordable basic power system based on this technology.”

Both teams produced devices that combine a standard silicon solar cell with a catalyst developed three years ago by professor Daniel Nocera. When submerged in water and exposed to sunlight, the devices cause bubbles of oxygen to separate out of the water.

The next step to producing a full, usable artificial leaf, explains Nocera, the Henry Dreyfus Professor of Energy and professor of chemistry, will be to integrate the final ingredient: an additional catalyst to bubble out the water’s hydrogen atoms. In the current devices, hydrogen atoms are simply dissociated into the solution as loose protons and electrons. If a catalyst could produce fully formed hydrogen molecules (H₂), the molecules could be used to generate electricity or to make fuel for vehicles. Realization of that step, Nocera says, will be the subject of a forthcoming paper.

The reports by the two teams were published in the journals Energy & Environmental Science on May 12, and the Proceedings of the National Academy of Sciences on June 6. Nocera encouraged two different teams to work on the project so that each could bring their special expertise to addressing the problem, and says the fact that both succeeded “speaks to the versatility of the catalyst system.”

Nocera’s ultimate goal is to produce an “artificial leaf” so simple and so inexpensive that it could be made widely available to the billions of people in the world who lack access to adequate, reliable sources of electricity. What’s needed to accomplish that, in addition to stepping up the voltage, is the addition of a second catalyst material to the other side of the silicon cell, Nocera says.

Making hydrogen gas (the bubbles) from a solar cell in water, a Sun Catalytix prototype.

The “leaf” system, by contrast, is “still a science project,” Nocera says. “We haven’t even gotten to what I would call an engineering design.” He hopes, however, that the artificial leaf could become a reality within three years.

About IPv6

June 12th, 2011 | by Anil |

As IPv6 is around the corner and set to grow in the coming few years, are you ready for it yet?
Find out using this test if your network are ready for IPv6.

IPv6 is an IP address standard designed to replace the current IPv4 protocol, which has been in use since the 1980s for routingInternet traffic. The new protocol has been available for several years now and supports several magnitudes more address spaces than IPv4, while also providing better security and reliability.

For more than 30 years, 32-bit addresses have served us well,but the growth of the Internet has mandated a need for more addresses than is possible with IPv4. IPv6 allows for vastly more addresses. IPv6 is the only long-term solution,  it has not yet been widely deployed. With IPv4 addresses expected to run out in 2011, only 0.2% of Internet users have native IPv6 connectivity.

Decomposition of an IPv6 address into its binary form.

While IPv4 allows 32 bits for an Internet Protocol address, and can therefore support 232 (4,294,967,296) addresses, IPv6 uses 128-bit addresses, so the new address space supports 2128 (approximately 340 undecillion or 3.4×1038) addresses. This expansion allows for many more devices and users on the internet as well as extra flexibility in allocating addresses and efficiency for routing traffic. It also eliminates the primary need for network address translation (NAT), which gained widespread deployment as an effort to alleviate IPv4 address exhaustion.

On 8 June, 2011, top websites and Internet service providers around the world, including Google, Facebook, Yahoo!, Akamai and Limelight Networks joined together with more than 1000 other participating websites in World IPv6 Day for a successful global-scale trial of the new Internet Protocol, IPv6. By providing a coordinated 24-hour “test flight”, the event helped demonstrate that major websites around the world are well-positioned for the move to a global IPv6-enabled Internet, enabling its continued exponential growth.

Organised by the Internet Society, the project was intended to raise awareness about the need to start the global transition to IPv6 and to enable participants to gather data about potential glitches.

Many of the problems are likely to stem from the simple facts that IPv6 is far newer and untested technology compared with IPv4, and that the two protocols will need to coexist for several years.

The real test of the IPv6 protocol, however, will come when companies start migrating to it in earnest in the next few years.

Small intro about interfaces

Understanding SCSI, ATA, SAS and SATA

The Differences Between Parallel and Serial Interfaces

For years the parallel interface has been widely used in storage systems. The need for increased bandwidth and flexibility in storage systems made the SCSIand ATA standards an inefficient option. A parallel interface is a channel capable of transferring date in parallel mode — that is transmitting multiple bits simultaneously. Almost all personal computers come with at least one parallel interface. Common parallel interfaces include SCSI and ATA. SCSI (sku4ze) Short for small computer system interface, a parallel interface standard used by Apple Macintosh computers, PCs and many UNIX systems for attaching peripheral devices to computers. Nearly all Apple Macintosh computers, excluding only the earliest Macs and the recent iMac, come with a SCSI port for attaching devices such as disk drives and printers. SCSI interfaces provide for data transmission rates (up to 80 megabytes per second). In addition, you can attach multiple devices to a single SCSI port, so that SCSI is really an I/O bus rather than simply an interface. ATA (Also known as IDE) is a disk drive implementation that integrates the controller on the disk drive itself. ATA is used to connect hard disk drives, CD-ROM drives and similar peripherals and supports 8/16-bit interface that transfer up to 8.3MB/s for ATA-2 and up to 100MB/s (ATA-6).

So, what do parallel interfaces have to do with SAS (Serial Attached SCSI) and SATA (Serial ATA)? A lot, actually. It is the architectural limitations of the parallel interfaces that serial technologies like SAS and SATA address. In contrast to multiple parallel data stream, data is transmitted serially, that is in a single steam, by wrapping multiple bits into packets and it is able to move that single stream faster than parallel technology. 

Serial Attached SCSI (SAS)

Abbreviated as SAS, Serial Attached SCSI, an evolution of parallel SCSI into a point-to-point serial peripheral interface in which controllers are linked directly to disk drives. SAS is a performance improvement over traditional SCSI because SAS enables multiple devices (up to 128) of different sizes and types to be connected simultaneously with thinner and longer cables; its full-duplex signal transmission supports 3.0Gb/s. In addition, SAS drives can be hot-plugged.

Serial ATA (SATA)

Often abbreviated as SATA, Serial ATA is an evolution of the Parallel ATA physical storage interface. Serial ATA is a serial link — a single cable with a minimum of four wires creates a point-to-point connection between devices. Transfer rates for Serial ATA begin at 150MB/s.

Starting with SATA, it extends the capabilities of ATA and offers transfer rates starting at 150MB/s and, after years of development, has moved to the mainstream of disk interfaces. The successor the SCSI interface is SAS at speeds of up to 3Gb/s. Additionally, it also addresses parallel interface issues such as drive addressability and limitations on the number of device per port connection.

SAS devices can communicate with both SATA and SCSI devices (the backplanes of SAS devices are identical to SATA devices). A key difference between SCSI and SAS devices is the addition in SAS devices of two data ports, each of which resides in a different SAS domain. This enables complete failover redundancy. If one path fails, there is still communication along a separate and independent path.

Cables & Connectors

Another big advantage of SATA over ATA is the cabling and connectors. The serial interface reduces the amount of wires needed to transmit data, making for much smaller cable size and making it easier to route and install SATA devices. The IDE cables used in parallel ATA systems are bulkier than Serial ATA cables and can only extend to 40cm long, while Serial ATA cables can extend up to one meter. In addition to the cabling, a new design of connectors is also used that reduces the amount of crosstalk between the wires, and the connector design also provides easier routing and better air flow.

The Benefits of SAS & SATA in Storage

Serial interfaces offer an improvement over older parallel SCSI (with a serial version) in storage applications and environments. These benefits include better performance, better scalability, and also better reliability as the parallel interfaces are at their limits of speed with reliable data transfers. SAS and SATA drives can also operate in the same environment while SCSI and ATA cannot. For example, using faster SAS drives for primary storage and offloading older data to cheaper SATA disks in the same subsystem, something that could not be achieved with SCSI and ATA.