Describing Cisco UCS Components
Fibre Channel Flow Control One of the major goals for the FC Protocol communication is to create a secure and reliable environment that allows all the FC frames to be received at the destination and to be received in the correct order. You saw how the whole FC switched fabric converges as well as how […]
Cisco UCS Components As discussed in previous chapters, data centers are built using different components that represent the physical infrastructure, the layers of operating systems and virtualization, and the different software and applications that provide the needed services, as well as the components used to build and manage the needed level of security and to […]
VSAN Overview It’s very common to use the analogy of Ethernet’s VLANs when explaining FC VSANs. Certainly, there are a lot of similarities between the two, but do not forget that these are features of two very different communication protocols, so there are some fundamental differences. So, what is a VSAN, and why do you […]
Fibre Channel Zoning The concept of using zones and zoning is the basic security mechanism in the Fibre Channel Protocol standard. With the many different types of servers and storage devices on the network, the need for security is crucial. For example, if a host were to access a disk that another host is using, […]
Cisco UCS Fabric Interconnect Product Overview The Cisco Fabric Interconnect is a core part of Cisco UCS. Here’s an overview of Cisco UCS Fabric Interconnect: The Cisco UCS Fabric Interconnects are now in their fourth generation. The Cisco UCS 6100 Fabric Interconnects were the first generation. They are no longer supported or sold. The second […]
Priority Flow Control In the Fibre Channel Protocol communication, the flow control is achieved by the buffer-to-buffer credit-based mechanism, where the receiving side is in control of the transmission. The Tx side does not start sending until it gets the R_RDY acknowledgment from the Rx side. After that, the Tx side transmits until it reaches […]
Enhanced Transmission Selection The PFC solves the challenges of marking and controlling which traffic can be stopped with a pause frame to avoid dropped frames, but on the same unified link, which has a certain bandwidth, different types of traffic are still flowing, and there is the need for a mechanism to manage that bandwidth. […]
DCBX Protocol The PFC and the ETS provide the means to divide, mark, and control the traffic and the bandwidth used, but there is still the need for these parameters and capabilities to be exchanged and negotiated between the devices in the converged infrastructure. The devices need to support the same standards. They need to […]
Fibre Channel Physical Addressing Two types of physical addresses are used in the Fibre Channel Protocol. The World Wide Names (WWNs), also known as World Wide Identifiers (WWIDs), are the physical addresses used in FCP communication. The WWNs are similar in concept to the Media Access Control (MAC) addresses in the Ethernet communication. WWNs have […]
Fibre Channel IDs Besides the physical WWN addresses, there is also a second addressing mechanism. It can be called logical, as the addresses are not hard-coded in the hardware; instead, they are generated by the switched fabric and assigned to the FC devices. These addresses are called Fibre Channel IDs (FCIDs) and are used for […]