This document discusses storage area networks (SANs) and fibre channel technology. It provides details on SAN components like servers, switches, storage arrays and cabling. It describes fibre channel connectivity options like point-to-point, arbitrated loop and switched fabric. Key concepts covered include fibre channel ports, addressing, protocols and topologies. Storage consolidation and high-speed data transfer between servers and storage are key benefits of SANs enabled by fibre channel technology.
Synchronization in distributed computingSVijaylakshmi
Synchronization in distributed systems is achieved via clocks. The physical clocks are used to adjust the time of nodes. Each node in the system can share its local time with other nodes in the system. The time is set based on UTC (Universal Time Coordination).
Synchronization in distributed computingSVijaylakshmi
Synchronization in distributed systems is achieved via clocks. The physical clocks are used to adjust the time of nodes. Each node in the system can share its local time with other nodes in the system. The time is set based on UTC (Universal Time Coordination).
This ppt covers different aspects about timing issues and various algorithms involved in having better sync between different systems in a distributed environment
Motivation
Types of Distributed Operating Systems
Network Structure
Network Topology
Communication Structure
Communication Protocols
Robustness
Design Issues
An Example: Networking
Coda (Constant Data Avaialabilty) is a distributed file system developed at Carnegie Mellon University . This presentation explains how it works and different aspects of it.
System Interconnect Architectures,Network Properties and Routing,Linear Array,
Ring and Chordal Ring,
Barrel Shifter,
Tree and Star,
Fat Tree,
Mesh and Torus,Dynamic InterConnection Networks,Dynamic bus ,Switch Modules
,Multistage Networks,Omega Network,Baseline Network,Crossbar Networks
SURVEYING BEST SUITABLE SCHEDULING ALGORITHM FOR WIMAX- WI-FI INTEGRATED HETE...cscpconf
To provide uninterrupted service to all subscribers in a wireless network, we need to incorporate a low cost, flexible Heterogeneous network which will be able to link with any kind
of network for efficient spectrum utilization, hence improved system capacity. In this connection, Wi-Fi/ Wi MAX integrated network seems to be an ideal solution as it is able to
provide easy deployment, high speed data rate and wide range coverage with high throughput, low end to end delay, flat and low jitter. Wi-Fi/ WiMAX integrated network provides Quality of
Service (QoS) that can support all kinds of real-time application in wireless networks that includes priority scheduling and queuing for bandwidth allocation that is based on traffic
scheduling algorithms within wireless networks. In this paper, we have designed a Wi-Fi/ WiMAX integrated network and analyze the performance of different scheduling algorithms for
that integrated network and highlight our findings on the scheduling algorithm which will give the best performance for a heterogeneous network.
This ppt covers different aspects about timing issues and various algorithms involved in having better sync between different systems in a distributed environment
Motivation
Types of Distributed Operating Systems
Network Structure
Network Topology
Communication Structure
Communication Protocols
Robustness
Design Issues
An Example: Networking
Coda (Constant Data Avaialabilty) is a distributed file system developed at Carnegie Mellon University . This presentation explains how it works and different aspects of it.
System Interconnect Architectures,Network Properties and Routing,Linear Array,
Ring and Chordal Ring,
Barrel Shifter,
Tree and Star,
Fat Tree,
Mesh and Torus,Dynamic InterConnection Networks,Dynamic bus ,Switch Modules
,Multistage Networks,Omega Network,Baseline Network,Crossbar Networks
SURVEYING BEST SUITABLE SCHEDULING ALGORITHM FOR WIMAX- WI-FI INTEGRATED HETE...cscpconf
To provide uninterrupted service to all subscribers in a wireless network, we need to incorporate a low cost, flexible Heterogeneous network which will be able to link with any kind
of network for efficient spectrum utilization, hence improved system capacity. In this connection, Wi-Fi/ Wi MAX integrated network seems to be an ideal solution as it is able to
provide easy deployment, high speed data rate and wide range coverage with high throughput, low end to end delay, flat and low jitter. Wi-Fi/ WiMAX integrated network provides Quality of
Service (QoS) that can support all kinds of real-time application in wireless networks that includes priority scheduling and queuing for bandwidth allocation that is based on traffic
scheduling algorithms within wireless networks. In this paper, we have designed a Wi-Fi/ WiMAX integrated network and analyze the performance of different scheduling algorithms for
that integrated network and highlight our findings on the scheduling algorithm which will give the best performance for a heterogeneous network.
Wireless communication is one of the fastest-growing technologies.
The demand for connecting devices without the use of cables is increasing everywhere.
Wireless LANs can be found on college campuses, in office buildings, and in many public areas
Unified Fabric: Data Centre Bridging and FCoE ImplementationCSCJournals
In the past decade cloud computing has become the buzzword in IT world. The implementation of cloud based computing and storage technology changed the way of how network infrastructure is built inside an enterprise. As technology has improved and the cloud based storage systems become more affordable, a number of enterprises started outsourcing their data management due to a number of reasons. But still a majority of large enterprises and SMB (small medium businesses) prefer to manage their own in-house data centers and storage area networks. The reason being is the control, security and integrity of stored data on cloud storage servers. In this paper, we will discuss the most commonly implemented SAN technology, fibre channel (FC) in comparison with the new technology called Fibre Channel over Ethernet (FCoE). These results will help SAN engineers and designers select the best technology between the two in terms of performance, scalability, cost, maintenance, space, cooling, equipment, cabling, management, adapters, labor cost and manpower. Implementation of FC and FCoE has been done to explore the different features of both technologies. Furthermore, how to build a reliable, scalable and secure storage area network has been demonstrated. This study has been carried out on Cisco Nexus, Cisco MDS and Cisco UCS platform.
A Study on Access Point Selection Algorithms in Wireless Mesh NetworksEswar Publications
In IEEE 802.11 based wireless mesh network (WMN), a mesh client often finds multiple access points (AP) to associate with. How to select the best AP is the open research problem. The traditional AP selection method defined by IEEE 802.11 standard is based on received signal strength. This method is proven inefficient as it does not consider many important factors such as channel conditions, AP load, etc. Many alternate solutions have been proposed so far in the literature, but they are all focused on wireless local area network (WLAN) environment. As there are significant differences between WLAN and WMN, all these proposed association mechanisms must be redesigned to fit into WMN environment. This paper studies the AP selection problem in the context of WMN. We critically analyze the existing work and identify technical challenges involved in AP selection problem. This paper also provides directions to design the metrics of AP selection method in WMN.
These slides explain the Protocol Framework for 5G mmWave Backhaul Network, as a part of a project presentation for the course Telecom Architecture at Northeastern University.
Image steganography techniques can be classified into two major categories such as spatial domain techniques and frequency domain techniques.
In spatial domain techniques the secret message is hidden inside the image by applying some manipulation over the different pixels of the image.
In frequency domain techniques the image is transformed to another form by applying a transformation like discrete wavelet transform and then the message is hidden by applying any of the usual embedding techniques.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
5. Organizations are experiencing an explosive growth in information.
This information needs to be stored, protected, optimized, and
managed efficiently. Data center managers are burdened with the
challenging task of providing low-cost, high-performance information
management solutions. An effective information management solution
must provide the following:
• Just-in-time information to business users
• Integration of information infrastructure with business processes
• Flexible and resilient storage architecture
This chapter provides detailed insight into the FC technology on which a SAN
is deployed and also reviews SAN design and management fundamentals.Ali Broumandnia, Broumandnia@gmail.com 5
6. 6.1 Fibre Channel: Overview
The FC architecture forms the fundamental construct of the SAN
infrastructure. Fibre Channel is a high-speed network
technology that runs on high-speed optical fiber cables (preferred
for front-end SAN connectivity) and serial copper cables
(preferred for back-end disk connectivity). The FC technology
was created to meet the demand for increased speeds of data
transfer among computers, servers, and mass storage subsystems.
Ali Broumandnia, Broumandnia@gmail.com 6
7. 6.2 The SAN and Its Evolution
A storage area network (SAN) carries data between servers
(also known as hosts) and storage devices through fibre channel
switches (see Figure 6-1). A SAN enables storage consolidation
and allows storage to be shared across multiple servers. It
enables organizations to connect geographically dispersed
servers and storage.
Ali Broumandnia, Broumandnia@gmail.com 7
9. 6.3 Components of SAN
A SAN consists of three basic components: servers, network
infrastructure, and storage. These components can be further broken
down into the following key elements:
• Node Ports
• Cabling
• Interconnect Devices
• Storage Arrays
• SAN Management Software
Ali Broumandnia, Broumandnia@gmail.com 9
10. 6.3.1 Node Ports
In fibre channel, devices such as hosts, storage and tape libraries
are all referred to as nodes. Each node is a source or destination
of information for one or more nodes. Each node requires one or
more ports to provide a physical interface for communicating
with other nodes. These ports are integral components of an HBA
and the storage front-end adapters. A port operates in full-duplex
data transmission mode with a transmit (TX) link and a receive
(Rx) link (see Figure 6-3).
Ali Broumandnia, Broumandnia@gmail.com 10
13. 6.3.2 Cabling
SAN implementations use optical fiber cabling. Copper can be
used for shorter distances for back-end connectivity, as it
provides a better signal-to-noise ratio for distances up to 30
meters. Optical fiber cables carry data in the form of light.
There are two types of optical cables, multi-mode and single-
mode. Multi-mode fiber (MMF) cable carries multiple beams
of light projected at different angles simultaneously onto the
core of the cable (see Figure 6-4 (a)).
Ali Broumandnia, Broumandnia@gmail.com 13
14. Based on the bandwidth, multi-mode fibers are classified as OM1
(62.5μm), OM2 (50μm) and laser optimized OM3 (50μm). In an MMF
transmission, multiple light beams traveling inside the cable tend to
disperse and collide. This collision weakens the signal strength after it
travels a certain distance a process known as modal dispersion. An MMF
cable is usually used for distances of up to 500 meters because of signal
degradation (attenuation) due to modal dispersion. Single-mode fiber
(SMF) carries a single ray of light projected at the center of the core (see
Figure 6-4 (b)).
Ali Broumandnia, Broumandnia@gmail.com 14
17. 6.3.3 Interconnect Devices
Hubs, switches, and directors are the interconnect devices commonly
used in SAN. Hubs are used as communication devices in FC-AL
implementations. Hubs physically connect nodes in a logical loop or a
physical star topology. All the nodes must share the bandwidth because
data travels through all the connection points. Because of availability of
low cost and high performance switches, hubs are no longer used in
SANs. Switches are more intelligent than hubs and directly route data
from one physical port to another. Therefore, nodes do not share the
bandwidth. Instead, each node has a dedicated communication path,
resulting in bandwidth aggregation.
Ali Broumandnia, Broumandnia@gmail.com 17
18. 6.3.4 Storage Arrays
The fundamental purpose of a SAN is to provide host access to storage
resources. The capabilities of intelligent storage arrays are detailed in
Chapter 4. The large storage capacities offered by modern storage arrays
have been exploited in SAN environments for storage consolidation and
centralization. SAN implementations complement the standard features
of storage arrays by providing high availability and redundancy,
improved performance, business continuity, and multiple host
connectivity.
Ali Broumandnia, Broumandnia@gmail.com 18
19. 6.3.5 SAN Management Software
SAN management software manages the interfaces between hosts,
interconnect devices, and storage arrays. The software provides a view
of the SAN environment and enables management of various resources
from one central console. It provides key management functions,
including mapping of storage devices, switches, and servers, monitoring
and generating alerts for discovered devices, and logical partitioning of
the SAN, called zoning. In addition, the software provides management
of typical SAN components such as HBAs, storage components, and
interconnecting devices.
Ali Broumandnia, Broumandnia@gmail.com 19
20. 6.4 FC Connectivity
The FC architecture supports three basic interconnectivity options:
• point-to point
• Fibre Channel Arbitrated loop (FC-AL)
• fabric connect
Ali Broumandnia, Broumandnia@gmail.com 20
21. 6.4.1 Point-to-Point
Point-to-point is the simplest FC configuration two devices are
connected directly to each other, as shown in Figure 6-6. This
configuration provides a dedicated connection for data transmission
between nodes. However, the point-to-point configuration offers
limited connectivity, as only two devices can communicate with each
other at a given time. Moreover, it cannot be scaled to accommodate a
large number of network devices. Standard DAS uses point to point
connectivity.
Ali Broumandnia, Broumandnia@gmail.com 21
23. 6.4.2 Fibre Channel Arbitrated Loop
In the FC-AL configuration, devices are attached to a shared loop, as
shown in Figure 6-7. FC-AL has the characteristics of a token ring
topology and a physical star topology. In FC-AL, each device contends
with other devices to perform I/O operations. Devices on the loop must
“arbitrate” to gain control of the loop. At any given time, only one device
can perform I/O operations on the loop.
As a loop configuration, FC-AL can be implemented without any
interconnecting devices by directly connecting one device to another in a
ring through cables. However, FC-AL implementations may also use hubs
whereby the arbitrated loop is physically connected in a star topology.
Ali Broumandnia, Broumandnia@gmail.com 23
25. • FC-AL shares the bandwidth in the loop. Only one device can perform
I/O operations at a time. Because each device in a loop has to wait for
its turn to process an I/O request, the speed of data transmission is low
in an FC-AL topology.
• FC-AL uses 8-bit addressing. It can support up to 127 devices on a
loop.
• Adding or removing a device results in loop re-initialization, which
can cause a momentary pause in loop traffic.
Ali Broumandnia, Broumandnia@gmail.com 25
26. FC-AL Transmission
When a node in the FC-AL topology attempts to transmit data, the node
sends an arbitration (ARB) frame to each node on the loop. If two nodes
simultaneously attempt to gain control of the loop, the node with the
highest priority is allowed to communicate with another node. This
priority is determined on the basis of Arbitrated Loop Physical Address
(AL-PA) and Loop ID, described later in this chapter.
When the initiator node receives the ARB request it sent, it gains control
of the loop. The initiator then transmits data to the node with which it has
established a virtual connection. Figure 6-8 illustrates the process of data
transmission in an FC-AL configuration.Ali Broumandnia, Broumandnia@gmail.com 26
28. 1) High priority initiator, Node A inserts the ARB frame in the loop.
2) ARB frame is passed to the next node (Node D) in the loop.
3) Node D receives high priority ARB, therefore remains idle.
4) ARB is forwarded to next node (Node C) in the loop.
5) Node C receives high priority ARB, therefore remains idle.
6) ARB is forwarded to next node (Node B) in the loop.
7) Node B receives high priority ARB, therefore remains idle and
8) ARB is forwarded to next node (Node A) in the loop.
9) Node A receives ARB back; now it gains control of the loop and can start
communicating with target Node B.
Ali Broumandnia, Broumandnia@gmail.com 28
29. 6.4.3 Fibre Channel Switched Fabric
Unlike a loop configuration, a Fibre Channel switched fabric (FC-SW)
network provides interconnected devices, dedicated bandwidth, and
scalability. The addition or removal of a device in a switched fabric is
minimally disruptive; it does not affect the ongoing traffic between other
devices. FC-SW is also referred to as fabric connect. A fabric is a logical
space in which all nodes communicate with one another in a network. This
virtual space can be created with a switch or a network of switches. Each
switch in a fabric contains a unique domain identifier, which is part of the
fabric’s addressing scheme. In FC-SW, nodes do not share a loop; instead,
data is transferred through a dedicated path between the nodes. Each port
in a fabric has a unique 24-bit fibre channel address for communication.
Figure 6-9 shows an example of FC-SW.Ali Broumandnia, Broumandnia@gmail.com 29
31. When the number of tiers in a fabric increases, the distance
that a fabric management message must travel to reach each
switch in the fabric also increases. The increase in the
distance also increases the time taken to propagate and
complete a fabric reconfiguration event, such as the addition
of a new switch, or a zone set propagation event (detailed
later in this chapter). Figure 6-10 illustrates two-tier and
three-tier fabric architecture.
Ali Broumandnia, Broumandnia@gmail.com 31
33. FC-SW Transmission
FC-SW uses switches that are intelligent devices. They can
switch data traffic from an initiator node to a target node
directly through switch ports. Frames are routed between
source and destination by the fabric. As shown in Figure 6-11,
if node B wants to communicate with node D, Nodes should
individually login first and then transmit data via the FC-SW.
This link is considered a dedicated connection between the
initiator and the target.
Ali Broumandnia, Broumandnia@gmail.com 33
35. 6.5 Fibre Channel Ports
Ports are the basic building blocks of an FC network. Ports
on the switch can be one of the following types:
• N_port
• NL_port
• E_port
• F_port
• FL_port
• G_port
Ali Broumandnia, Broumandnia@gmail.com 35
37. 6.6 Fibre Channel Architecture
• Sustained transmission bandwidth over long distances.
• Support for a larger number of addressable devices over a
network. Theoretically, FC can support over 15 million
device addresses on a network.
• Exhibits the characteristics of channel transport and
provides speeds up to 8.5 Gb/s (8 GFC).
Ali Broumandnia, Broumandnia@gmail.com 37
38. 6.6.1 Fibre Channel Protocol Stack
It is easier to understand a communication protocol by
viewing it as a structure of independent layers. FCP defines
the communication protocol in five layers: FC-0 through FC-
4 (except FC-3 layer, which is not implemented). In a layered
communication model, the peer layers on each node talk to
each other through defined protocols. Figure 6-13 illustrates
the fibre channel protocol stack.
Ali Broumandnia, Broumandnia@gmail.com 38
40. 1. FC-4 Upper Layer Protocol
SCSI, HIPPI Framing Protocol, Enterprise Storage
Connectivity (ESCON), ATM, and IP.
2. FC-2 Transport Layer
fabric services, classes of service, flow control, and
routing.
3. FC-1 Transmission Protocol
4. FC-0 Physical Interface
Ali Broumandnia, Broumandnia@gmail.com 40
41. 6.6.2 Fibre Channel Addressing
An FC address is dynamically assigned when a port logs on to the
fabric. The FC address has a distinct format that varies according to
the type of node port in the fabric. These ports can be an N_port
and an NL_port in a public loop, or an NL_port in a private loop.
The first field of the FC address of an N_port contains the domain
ID of the switch (see Figure 6-14). This is an 8-bit field. Out of the
possible 256 domain IDs, 239 are available for use; the remaining
17 addresses are reserved for specific services. For example,
FFFFFC is reserved for the name server, and FFFFFE is reserved
for the fabric login service. The maximum possible number of
N_ports in a switched fabric is calculated as 239 domains × 256
areas × 256 ports = 15,663,104 Fibre Channel addresses.Ali Broumandnia, Broumandnia@gmail.com 41
43. FC Address of an NL_port
The FC addressing scheme for an NL_port differs from other ports. The
two upper bytes in the FC addresses of the NL_ports in a private loop
are assigned zero values. However, when an arbitrated loop is connected
to a fabric through an FL_port, it becomes a public loop. In this case, an
NL_port supports a fabric login. The two upper bytes of this NL_port
are then assigned a positive value, called a loop identifier, by the switch.
The loop identifier is the same for all NL_ports on a given loop. Figure
6-15 illustrates the FC address of an NL_port in both a public loop and
a private loop. The last field in the FC addresses of the NL_ports, in
both public and private loops, identifies the AL-PA. There are 127
allowable AL-PA addresses; one address is reserved for the FL_port on
the switch.Ali Broumandnia, Broumandnia@gmail.com 43
45. World Wide Names
Each device in the FC environment is assigned a 64-bit unique identifier
called the World Wide Name (WWN). The Fibre Channel environment
uses two types of WWNs: World Wide Node Name (WWNN) and World
Wide Port Name (WWPN). Unlike an FC address, which is assigned
dynamically, a WWN is a static name for each device on an FC network.
WWNs are similar to the Media Access Control (MAC) addresses used in
IP networking. WWNs are burned into the hardware or assigned through
software. Several configuration definitions in a SAN use WWN for
identifying storage devices and HBAs. The name server in an FC
environment keeps the association of WWNs to the dynamically created
FC addresses for nodes. Figure 6-16 illustrates the WWN structure for an
array and the HBA.Ali Broumandnia, Broumandnia@gmail.com 45
47. 6.6.3 FC Frame
An FC frame (Figure 6-17) consists of five parts: start of frame (SOF),
frame header, data field, cyclic redundancy check (CRC), and end of
frame (EOF). The SOF and EOF act as delimiters. In addition to this role,
the SOF is a flag that indicates whether the frame is the first frame in a
sequence of frames. The frame header is 24 bytes long and contains
addressing information for the frame. It includes the following
information: Source ID (S_ID), Destination ID (D_ID), Sequence ID
(SEQ_ID), Sequence Count (SEQ_CNT), Originating Exchange ID
(OX_ID), and Responder Exchange ID (RX_ID), in addition to some
control fields.
Ali Broumandnia, Broumandnia@gmail.com 47
49. The S_ID and D_ID are standard FC addresses for the source port and the
destination port, respectively. The SEQ_ID and OX_ID identify the frame
as a component of a specific sequence and exchange, respectively. The
frame header also defines the following fields:
• Routing Control (R_CTL)
• Class Specific Control (CS_CTL)
• TYPE
• Data Field Control (DF_CTL)
• Frame Control (F_CTL)
Ali Broumandnia, Broumandnia@gmail.com 49
50. 6.6.4. Structure and Organization of
FC Data
• Exchange operation
An exchange operation enables two N_ports to identify and manage a set of
information units.
• Sequence
A sequence refers to a contiguous set of frames that are sent from one port
to another.
• Frame
A frame is the fundamental unit of data transfer at Layer 2. Each frame can
contain up to 2,112 bytes of payload.Ali Broumandnia, Broumandnia@gmail.com 50
51. 6.6.5 Flow Control
Flow control defines the pace of the flow of data frames
during data transmission. FC technology uses two flow-
control mechanisms:
• buffer-to-buffer credit (BB_Credit)
• end-to-end credit (EE_Credit)
Ali Broumandnia, Broumandnia@gmail.com 51
52. 6.6.6 Classes of Service
The FC standards define different classes of service to meet
the requirements of a wide range of applications. The table
below shows three classes of services and their features
(Table 6-1).
Ali Broumandnia, Broumandnia@gmail.com 52
54. 6.7 Zoning
Zoning is an FC switch function that enables nodes within
the fabric to be logically segmented into groups that can
communicate with each other (see Figure 6-18). When a
device (host or storage array) logs onto a fabric, it is
registered with the name server. When a port logs onto the
fabric, it goes through a device discovery process with other
devices registered in the name server. The zoning function
controls this process by allowing only the members in the
same zone to establish these link-level services.
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56. Multiple zone sets may be defined in a fabric, but only one
zone set can be active at a time. A zone set is a set of zones
and a zone is a set of members. A member may be in
multiple zones. Members, zones, and zone sets form the
hierarchy defined in the zoning process (see Figure 6-19).
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60. 6.8 Fibre Channel Login Types
Fabric services define three login types:
• Fabric login (FLOGI) is performed between an N_port and
an F_port.
• Port login (PLOGI) is performed between an N_port and
another N_port to establish a session.
• Process login (PRLI) is also performed between an N_port
and another N_port.
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61. 6.9 FC Topologies
Fabric design follows standard topologies to connect
devices. Core-edge fabric is one of the popular topology
designs. Variations of core-edge fabric and mesh topologies
are most commonly deployed in SAN implementations.
• Core-Edge Fabric
• Mesh Topology
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64. 6.9.2 Mesh Topology
In a mesh topology, each switch is directly connected to other
switches by using ISLs. This topology promotes enhanced
connectivity within the SAN. When the number of ports on a
network increases, the number of nodes that can participate and
communicate also increases. A mesh topology may be one of the
two types: full mesh or partial mesh. In a full mesh, every switch
is connected to every other switch in the topology. Full mesh
topology may be appropriate when the number of switches
involved is small. A typical deployment would involve up to four
switches or directors, with each of them servicing highly localized
host-to-storage traffic.Ali Broumandnia, Broumandnia@gmail.com 64
65. In a full mesh topology, a maximum of one ISL or hop is required
for host-to-storage traffic. In a partial mesh topology, several hops
or ISLs may be required for the traffic to reach its destination.
Hosts and storage can be located anywhere in the fabric, and
storage can be localized to a director or a switch in both mesh
topologies. A full mesh topology with a symmetric design results
in an even number of switches, whereas a partial mesh has an
asymmetric design and may result in an odd number of switches.
Figure 6-23 depicts both a full mesh and a partial mesh topology.
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67. 6.10 Concepts in Practice: EMC
Connectrix
This section discusses the Connectrix connectivity products
offered by EMC that provide connectivity in large-scale,
workgroup, mid-tier, and mixed iSCSI and FC environments.
• Connectrix Switches
• Connectrix Directors
• Connectrix Management Tools
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68. EMC offers the following connectivity products under the
Connectrix brand :
• Enterprise directors
• Departmental switches
• Multiprotocol routers
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70. Summary
The SAN has enabled the consolidation of storage and benefited
organizations by lowering the cost of storage service delivery.
SAN reduces overall operational cost and downtime and enables
faster application deployment. SANs and tools that have emerged
for SANs enable data centers to allocate storage to an application
and migrate workloads between different servers and storage
devices dynamically. This significantly increases server utilization.
SANs simplify the business-continuity process because
organizations are able to logically connect different data centers
over long distances and provide cost-effective, disaster recovery
services that can be effectively tested.Ali Broumandnia, Broumandnia@gmail.com 70
71. The adoption of SANs has increased with the decline of hardware prices and has
enhanced the maturity of storage network standards. Small and medium size
enterprises and departments that initially resisted shared storage pools have now
begun to adopt SANs. This chapter detailed the components of a SAN and the FC
technology that forms its backbone. FC meets today’s demands for reliable, high-
performance, and low-cost applications. The interoperability between FC switches
from different vendors has enhanced significantly compared to early SAN
deployments. The standards published by a dedicated study group within T11 on
SAN routing, and the new product offerings from vendors, are now
revolutionizing the way SANs are deployed and operated. Although SANs have
eliminated islands of storage, their initial implementation created islands of SANs
in an enterprise. The emergence of the iSCSI and FCIP technologies, detailed in
Chapter 8, has pushed the convergence of the SAN with IP technology, providing
more benefits to using storage technologies.Ali Broumandnia, Broumandnia@gmail.com 71