What are the benefits of FCoE?

[Nikah Ulana]

I have found some threads over here discussing about the FCoE. I know that there are should be some good points, but why many are looking for it. In simple language, I want to know about benefits of FCoE. I am sure that you people will provide me some points soon. It would be helpful for me, if you provide some notes about Fibre Channel and Fibre Media.

[StephanieRice]

With Fibre Channel over Ethernet has the following advantages:

• Only one cable type, existing, proven technology
• better cooling in the rack, lower power consumption
• Investment protection: FC devices can be reused
• 10 GE with no speed restrictions

For Ethernet frames can be lost, and the latency is quite large. The higher protocols (TCP / IP) network stack ensure secure transmission of packet repetition or new request. For FCoE there are so few extensions for Ethernet (FCoCEE):

• No frame loss (or non-PAUSE PAUSE)
• Traffic Management 802.1au
• Prioritization of FC data to non-FC data 802.1Q (QoS)
• In the same frame as in pure FC-latency networks

[McGrawh]

For FCoE there are so few extensions for Ethernet (FCoCEE):

* No frame loss (or non-PAUSE PAUSE)
* Traffic Management 802.1au
* Prioritization of FC data to non-FC data 802.1Q (QoS)
* In the same frame as in pure FC-latency networks

Thus little or no adjustments in the drivers are necessary. Ethernet offers the possibility of using PAUSE, all traffic to stop, but not very effectively. Including FCoE packets are hindered. Therefore, here comes "Per priority PAUSE" new to the application, which enables the prioritization of packets with the result that the FCoE frames are not hindered. In this way, the big FC storage systems (tape robot, Library, RAID) transparent endpoints as in the past used to be for.

[Samsher]

The connection-oriented and byte-iSCSI was developed for IP networks and has a TCP overhead. In addition, gateways between FC and iSCSI are expensive. The flow is controlled purely from the upper protocols (TCP) and is thus in poor connections at the expense of bandwidth and performance. These disadvantages will avoid FCoE. Another important prerequisite for FCoE is the function with standard Ethernet switches. However, it is left to the manufacturers, special FCoE services on the switch to implement. Instead of the so-called host bus adapter (HBA) that connect the internal system with the fiber to be used for cards that act as the operating system compared to HBA and appear to the network switch as a network card.

[Paramartha]

When the two types of fiber media fiber types are used:

• Multimode
• Single-/Monomode

The maximum transmission distance for a multimode fiber is the core diameter of 50 microns approximately 550 feet, the core diameter of 62.5 microns, only about 275 meters. If we reduce the core diameter down to 3 microns, one comes to the single-mode fiber, also called single-mode fiber. The outer diameter of the fiber is both about 125 microns. (Wavelength 1310 or 1550) with the long-wavelength lasers, we can bridge distances up to 250 km. FC Fibre offers the advantage of combining long distances almost without loss and also still have a high resistance to electric and magnetic fields, the laying of the sensitive thin glass fibers is not always easy. Often, therefore, redundant or non-activated fibers in the first line bundles are laid, the so-called "dark fiber".

[Cadallic]

Although the term "FCoE" would suggest more on fiber, it is Fibre Channel (FC) protocol, the two types of media - supported by differing physical layers - copper and fiber. Copper is used mostly in the system for distances up to 30 meters, it usually comes to fiber deployment. As interconnect FC came in the early days with 1 Gbit / s as FC-AL (Fibre Channel arbitrated loop) with shared bandwidth usage as a bus used. With time came FC switches - often called "Fabrics" is named - at low prices on the market, and thus the peer technology with exclusive use of bandwidth is also possible here. Fabric is understood under the networking of FC switches.

[Rover]

The topology is now mostly made of switched fabric, that is a point-to-point connection with currently 8 Gbit / s (about twice a 800 MB / s full duplex) per data direction. The FC protocol is designed for high-performance storage networks, and thus for the secure, fast transport of large amounts of data. Thanks multipathing redundant data paths are possible. The 64-bit signal-hexadecimal "Worldwide Node Name (WWNN) is analogous to the MAC address from Ethernet to uniquely identify the device. Each FC port is also unique with its "Worldwide Port Name (WWPN) identifier. WWNN and WWPN are very similar. A four-port HBA therefore has four unique WWPN and WWNN. FC networks whose functions have low latency and may lose under any circumstances, packages, as this would cause data loss or corruption. With FCIP and iFCP IP provides a degree of resilience, but also causes an overhead. other hand, if FC frames in Ethernet packets are transported, it must be borne by the quality-of-service packet loss and high latency of Ethernet bill.