by Dinesh Thakur Category: Communication Networks

Transmission is the method by which computer networks send electrical signals. Data communication is concerned with the process of exchanging data electronically between two communication devices. In a local area network, all communication functions are performed through direct cables. Computers located far away are connected through a special form of data communication link. The existing telephone or telegraphic network may also be used for connecting computers located at remote locations.



 
by Dinesh Thakur Category: Communication Networks

Generally, some people use the term "Ethernet" or ether refers to cable. Ethernet was the original product designed by Xerox PARC based on Bob Metcalfe's idea. It was later upgraded to 10 Mbps by Xerox, Intel and DEC.

 
by Dinesh Thakur Category: Network Technologies

FDDI stands for Fiber Distributed Data Interface. It is a high-speed, high-bandwidth network based on optical transmissions. It is most often used as a network backbone, for connecting high-end computers (mainframes, minicomputers, and peripherals), and for LANs connecting high-performance engineering, graphics, and other workstations that demand a rapid transfer of large amounts of data. It can transport data at a rate of 100 Megabits per second and can support up to 500 stations on a single network. FDDI was designed to run through fiber cables, transmitting light pulses to convey information between stations, but it can also run on copper using electrical signals. It is relatively expensive to implement, although the mixing of fiber-optic with copper cabling can hold down the cost.



 
by Dinesh Thakur Category: Network Technologies

Digital Equipment Corporation (DEC) has given support to network connectivity for networks of its own and networks of other vendors also. DEC has its own architecture known as Digital Network Architecture (DNA) the product that implements the architecture is known as DEC net. The DNA was developed during 1974, to provide communication facility between various DEC systems.

 
by Dinesh Thakur Category: Network Technologies

The Systems Network Architecture (SNA) from IBM uses a 7 layer architecture similar to the OSI model.

 
by Dinesh Thakur Category: Network Technologies

Definition: Storage area network is abbreviated as SAN. SAN is a network which is designed to attach computer storage devices such as disk array controllers and tape libraries to servers. SAN network can be accessed by multiple computers. It is a secure and high-speed data network. It is also known as SAN storage, SAN network, etc.
We assemble the storage area network by using three principal components:
•    Cabling
•    Host bus adapters
•    Switches
We attach the switches to storage arrays and servers. Generally, all storage arrays were hard disk drives but nowadays flash solid-state drives are used.

A storage area network is most commonly used for:
• For improving the availability of applications
• For enhancing the performance of applications like off-loading storage functions.
• For increasing the utilization of storage and its effectiveness which include consolidating storage resources, tiered storage, etc.
• For improving security and data protection
• For organizing Business Continuity Management activities.

Storage area network

Types of SAN (Storage area network)

The most commonly used SAN protocols are as follows:
Fibre Channel Protocol (FCP): it is the most widely used SAN protocol. It makes use of Fibre Channel transport protocol which is embedded with the SCSI commands. This protocol is deployed in 70 to 80% of the total SAN market.
Internet Small Computer System Interface: It is the another most common type of SAN protocol which is used in the SAN market. It is deployed in 10 to 15% of the total SAN market. This protocol encapsulates with the SCSI command inside an Ethernet frame. It also makes use of an IP Ethernet network for transport purpose.
Fibre Channel over Ethernet (FCoE): it is deployed in less than 5% of the SAN market. It is somewhere similar to iSCSI as it also encapsulated with SCSI command inside an Ethernet frame.
Similarly, it also makes use of IP Ethernet network for transport.
Non-Volatile Memory Express over Fibre Channel (FC-NVMe): it is an interface protocol. We make use of this protocol for accessing the flash storage. We can access this flash storage via PCI Express (PCIe) bus. It supports tens of thousands of parallel queues. Each queue can help tens of thousands of concurrent commands.

SAN Use Cases

We deploy the storage area network in support of business-critical, performance-sensitive applications which are illustrated as below:
Oracle databases: Oracle databases are business-critical. It requires high performance and availability.
Large virtualization deployments using VMware, KVM, or Microsoft Hyper-V: This kind of environments extend to thousands of virtual machines. These machines run a broad range of operating system and applications. It has different performance requirements. The large virtual environments may concentrate on many forms.
SAP or other massive ERP or CRM environments: San architectures are ideal for customer resource management workloads and enterprise resource planning.
Microsoft SQL server databases: MS SQL Server database similar to Oracle database stores the most valuable data of the enterprises. So, they also require high performance and availability.
Large virtual desktop infrastructures (VDIs): it serves virtual desktops to large numbers. By doing the centralization of virtual desktops, the data protection and data security can be easily managed by the organizations.

Advantages of SAN

Storage virtualization: In this, the capacity of the server is not linked to the single storage devices. Now we can make use of large and consolidated storage pools for software applications.
High-speed disk technologies: we can consider FC (Fiber Channel) as an example for this. FC is a network that offers speed for retrieval of data is more than 5 Gbps. In this, we can directly transfer the data from the source device to the target device such that there is either decidedly less or no intervention of servers. Also, storage-to-storage data transfer is also available.
Centralized backup: it contains advanced backup features which includes block level and incremental backups, streamline IT system administrator responsibilities, etc., In this, the backup of data is stored on local disks instead of multiple disks.
Dynamic Failover Protection: it provides continuous network operation. Suppose if our system fails in between, or some other maintenance problem occurs due to which it enables built-in redundancy and automatic rerouting of traffic, even then our operation will work.



 
by Dinesh Thakur Category: Network Technologies

Long-term Evolution abbreviated as LTE. We make use of LTE to refer to wireless broadband and other mobile network technologies. LTE standard was developed by the 3GPP (3rd Generation Partnership Project) in 2004.

 
by Dinesh Thakur Category: Network Technologies

Definition:  General Packet Radio Service is a packet-based wireless communication service. It promises data rate up to 114 kbps. It is a standard technology which extends the Global system. It abbreviated as GPRS. It is designed to replace the current circuit-switched services.

General Packet Radio Service is a non-voice and high-speed technology which is useful for the GSM networks. We make use of GPRS so that we can enable connections which depend on the internet protocol. As we know, IP supports a wide variety of applications. We can send and receive the compressed data and large volume data over the mobile network by using GPRS as the packet switching system used. So, before sending the data, it breaks the whole data into packets and then shifts them through the network. Now the data again assembled at the recipient side.



 
by Dinesh Thakur Category: Network Technologies

Cluster computing or High-Performance computing frameworks is a form of computing in which bunch of computers (often called nodes) that are connected through a LAN (local area network) so that, they behave like a single machine. A computer cluster help to solve complex operations more efficiently with much faster processing speed, better data integrity than a single computer and they only used for mission-critical applications.



 
by Dinesh Thakur Category: Network Technologies

A Wi-Fi network is made with many amenities, such as access points, antennas, bridges, controllers, etc. In this section, we will make an overview of the equipment in order to provide some features.

 
by Dinesh Thakur Category: Network Technologies

A sensor array is defined as a set of sensors connected to one another, each sensor being provided with a transceiver. Sensor networks are a new generation networks with specific properties, which do not fall within the conventional architectures.

 
by Dinesh Thakur Category: Network Technologies

Mesh networks (meshed networks) are ad-hoc networks in which routing points are immobile. Customers are connected by a wireless network access points and the access points are connected by wireless links.

 
by Dinesh Thakur Category: Network Technologies

Routing is the primary element of an ad-hoc network. It takes routing software in each network node to manage the transfer of IP packets. The simplest solution is obviously to have a direct routing, as illustrated in Figure, in which each network station can directly reach another station, without going through an intermediary. The simplest case corresponds to a small cell, with a diameter less than 100 m, as in an 802.11 network in ad-hoc mode.

 
by Dinesh Thakur Category: Network Technologies

Another big wireless network category is ad-hoc networks, where the infrastructure is composed as resorts themselves. The latter agreed to play the role of the router to allow the passages of information from one device to another, without these terminals are connected directly.



 
by Dinesh Thakur Category: Network Technologies

Wireless networks are developing due to the flexibility of their interface, which allows a user to change positions while staying connected. Communications between terminals can be made directly or via base stations, called access points, or AP (Access Point). Communication between access points can be wireless or cable. The flow rates of these networks are tens of megabits per second.

 
by Dinesh Thakur Category: Network Technologies

The local loop is to connect users to the first node, router or switch, the operator with whom the customer has a subscription. Broadband solutions is shared between the ATM for fixed links and Ethernet for wireless backhaul. One of the objectives in the Ethernet local loop is replaced by the ATM Ethernet solutions, particularly in the xDSL modems.

 
by Dinesh Thakur Category: Network Technologies

Ethernet on the WAN aims to transport Ethernet frames over long distances like states, countries, or the whole world, while providing quality service. Its advantages are a very low cost, the possibility of oversizing of the network, highly granular, well known technology and very simple and finally simplified management, since Ethernet is everywhere. You can go very fast in throughput with different levels of 1 and 10 Gbit/s and soon the 100 Gbit/s. The register of difficulties include the lack of reliability, packet loss less controlled and quality of services more difficult to obtain. However, several technologies are currently being developed to address these issues and provide a royal way for the arrival of Ethernet on the WAN.

 
by Dinesh Thakur Category: Network Technologies

After invading the world of business, Ethernet addresses the longer distances starting with the metropolitan area. The Metro Ethernet was born of this extension. This solution is supported in different settings but especially by the Forum MEF (Metro Ethernet Forum).

 
by Dinesh Thakur Category: Network Technologies

SONET (Synchronous Optical Network) is a proposal by Bellcore (Bell Communications Research), SONET is a technique of transport between two nodes, which defines the interface adopted for the NNI (Network Node Interface). She initially concerned that the interconnection of telephone networks of major operators, PTT, carrier, etc. The difficulty of standardization has been to find a compromise between the American, European and Japanese interests to interconnect different operator networks and national networks.

 
by Dinesh Thakur Category: Network Technologies

The LAP-F protocol (Link Access Protocol-Frame) was born with frame relay, designed to improve the performance of networks from the X.25 recommendation UITT. The latter has proved too heavy and therefore unable to increase rates, it took in search for a simplification.



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.