Describe the classful IP Addressing.
IP address is short for Internet Protocol (IP) address. IP address is a unique identifier for a computer or device (host) on a TCP/IP network. IP addresses work for communication between computers; people find it difficult to remember long strings of numbers. Many Internet servers also have an easy-to-remember name, such as nike.com.
The IP address space (all possible IP values) is divides into 3 classes: A, B, C.
–Class A: Network prefix is 8 bits long
–Class B: Network prefix is 16 bits long
–Class C: Network prefix is 24 bits long
• Each IP address contained a key, which identifies the class:
–Class A: IP address starts with “0”
–Class B: IP address starts with “10”
–Class C: IP address starts with “110”
Classful addressing, formally adopted as part of the Internet Protocol (IP). The IP address was 32 bits in size, just as today, but was managed considerably differently.
There were three address classes to choose from A, B, or C, corresponding to 8-bit, 16-bit, or 24-bit prefixes.
Addresses beginning with 0 were considered class A; addresses beginning 10 were class B; addresses beginning 110 class C. Two other classes were also defined, class D addresses beginning 1110 and class E addresses beginning 1111, though neither of these two address classes were normally used.
What is RAM? What is its purpose? What is the difference between static and dynamic memory?
The first form of RAM came about in 1947 with the use of the Williams tube. The second widely used form of RAM was magnetic-core memory, invented in 1947. Random access memory, usually known by its acronym RAM, is a class of media used in computers for data storage and retrieval. A RAM device is designed to allow data to be read or written in any order—that is, "at random." In addition, the speed at which a set of data can be accessed is independent of its location in the device.
What about the purpose of it? RAMs main advantage is its speed. Information can be loaded to it quickly, and processors, which have only minimal storage capacity, can operate on it quickly.While a user edits a document, for example, its text and formatting information resides in RAM. However, RAM is generally not used for long-term storage. Part of this is because the cost of RAM is much higher than the cost of typical disk drives. RAM also requires a constant flow of electricity, and the information it holds is lost if power is disconnected. Also Random-access memory is a form of computer data storage. RAM is much faster to read from and write to than other kinds of storage in a computer, such as a hard disk drive (HDD), optical drive.
|
|
|
Various types of RAM have been developed.DRAM stands for Dynamic Random Access Memory. It is used in most of the computers. It is the least expensive kind of RAM. It requires an electric current to maintain its electrical state. The electrical charge of DRAM decreases with time that may result in loss of DATA. DRAM is recharged or refreshed again and again to maintain its data. The processor cannot access the data of DRAM when it is being refreshed. That is why it is slow.
SRAM stands for Static Random Access Memory. It can store data without any need of frequent recharging. CPU does not need to wait to access data from SRAM during processing. That is why it is faster than DRAM. It utilizes less power than DRAM. SRAM is more expensive as compared to DRAM. It is normally used to build a very fast memory known as cache memory.
Different between SRAM and DRAM
SRAM
· It is faster than DRAM.
· It is more expensive as compared to DRAM.
· It does not need to be power – refreshed.
· Ituse lesspower.
· It holds data indefinitely as long as the computer is turned on.
· It is more complex and less compact.
DRAM
· It is slower than SRAM.
· Itislessexpensive.
· It has to be refreshed after each read operation.
· Ituse morepower.
· It holds data dynamically not indefinitely.
· It is less complex and more compact.
34. Why do networks have different topologies? What are the advantages of each topology?
Network Topology refers to layout of a network and how different nodes (A node can be a computer or some other device, such as a printer) in a network are connected to each other and how they communicate. This refers to the pattern formed when computers are connected on a network. Difference depends on devices, topologies are either physical (the physical layout of devices on a network) or logical (the way that the signals act on the network media, or the way that the data passes through the network from one device to the next) in the lecture 7 we studied 3 types of typology
1: Linear Bus 2: Star 3: Star bus or Tree topology
Дата добавления: 2018-06-01; просмотров: 340; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!