0
Local Area Network
Questions concerning the setting up, troubleshooting and operation of wired LANs used by businesses and other organizations
4,003 Questions
What are the advantages of UDP?
The advantages of TCP over UDP are quite clear, as TCP guarantees that the sent data actually arrives, that it arrives in order and that there are no duplicates, while UDP provides none of these guarantees (only offers "best effort" policy). Unlike TCP, UDP does not provide any flow and congestion control.
On the surface, an unreliable transport protocol like UDP may not seem very worthwhile or desirable. But in fact, UDP can be very useful in certain situations, and it enjoys one key advantage over TCP - speed. The reliability features built into TCP can be expensive in terms of overhead at execution time.
Therefore, many applications find UDP well-suited for their needs, for the following reasons:
No connection establishmentWhile TCP uses a three-way handshake before it starts to transfer data, UDP just blasts away without any formal preliminaries. Thus, UDP does not introduce any delay to establish a connection. This feature is most useful to applications which exchange sporadic and low-volume data.
No connection stateTCP maintains connection state in the end systems. This connection state includes receive and send buffers, congestion control parameters, and sequence and acknowledgment number parameters. This state information is needed to implement TCP's reliable data transfer service and to provide congestion control. UDP, on the other hand, does not maintain connection state and does not track any of these parameters. For this reason, a server devoted to a particular application can typically support many more active clients when the application runs over UDP rather than TCP.
Small segment header overheadThe TCP segment has 20 bytes of header overhead in every segment, whereas UDP only has 8 bytes of overhead. TCP needs more header fields in order to guarantee reliability, while UDP, that gives no guarantees, does not.
Unregulated send rateTCP has a congestion control mechanism that throttles the sender when one or more links between sender and receiver becomes excessively congested. This throttling can have a severe impact on real-time applications, which can tolerate some packet loss but require a minimum send rate. On the other hand, the speed at which UDP sends data is only constrained by the rate at which the application generates data, the capabilities of the source (CPU, clock rate, etc.) and the access bandwidth to the Internet. We should keep in mind, however, that the receiving host does not necessarily receive all the data. When the network is congested, a significant fraction of the UDP-transmitted data could be lost due to router buffer overflow. Thus, the receive rate is limited by network congestion even if the sending rate is not constrained.
Lower latencyWith TCP, if a packet is lost, but the next packet makes it through, the kernel will withhold that packet until the earlier packet can be re-sent. This is because TCP is a guaranteed, in-order, stream protocol. This means that "fresh" data will sit in the kernel, becoming "stale", while waiting for the TCP timeout to be retransmitted (a minimum of 3 seconds for a lost packet). This is why UDP is usually better for games, voice conferencing, and other low-latency applications.
Broadcast and multicastBeing a connection-oriented protocol, TCP does not support broadcast and multicast. Therefore, applications that require this kind of service will have to use UDP as a transport protocol.
Application flexibilityThe fact that UDP lacks built-in reliability mechanisms can be considered an advantage from the application designer's point of view. Building reliability directly into the application allows the application to "have its cake and eat it too". That is, application processes can communicate reliably without being constrained by the transmission rate constraints imposed by TCP's congestion control mechanism. Application-level reliability also allows an application to tailor its own application-specific form of error control.
For example, an interactive real-time may occasionally choose to retransmit a lost message, provided that round trip network delays are small enough to avoid adding significant playout delays. In fact, many of today's proprietary streaming applications do just this: they run over UDP, but they have built acknowledgements and retransmissions into the application in order reduce packet loss.
What is a computer or device on a network that handles shared network resources called?
Application server is incorrect.
The correct answer is System Software
Why are client server networks often installed in businesses instead of peer to peer networks?
First, I don't know that it's true that P2P networking doesn't exist in large IT environments. File/printer sharing and peer-to-peer applications, if the ports are opened on the local subnet, are frequently allowed, at least internally. Exposing P2P file-sharing apps outside of a corporate DMZ poses an unconscionable security hazard.
But from a centralized administration perspective--the more turnover you have with users, groups, apps, and access makes centralized administration the only effective solution for maximizing user uptime and network security.
How many host can you have for 10.20.50.0 subnet mask 255.255.255.0?
253.
Valid addresses would be from 10.20.50.1 to 10.20.50.254
10.20.50.0 is the network address.
10.20.50.255 is the network broadcast address.
Any network with a subnet mask of 255.255.255.0 will support 253 hosts.
Consideration of choosing network topology?
Considerations for selecting a topologySelecting an appropriate topology for your deployment environment depends upon several factors.
When you select a topology pattern, consider the following factors:
- Available hardware resources
- Application invocation patterns
- Types of business processes that you plan to implement (interruptible versus non-interruptible)
- How heavily you intend to use the Common Event Infrastructure (CEI)
- Individual scalability requirements
- Administrative effort involved
How do you upgrade a ten computer network?
First, you have to decide on the network topology you want to use. This will decide on the type of wiring necessary and any network connectivity devices.
Second, you have to decide whether this is a peer to peer network, or a client server network, which will also impact what software is installed on the network and how it is supported.
For 10 systems or less, a peer to peer network is a good choice; all you need is the wiring, and a simple device such as a hub or switch (a switch would be better). Then, wire all the systems to go to the switch, and configure the network interfaces on each device.
The Class B IPv4 address network ID is located in the?
The first 16 bits is the location of the Class B IPv4 address network ID based in classful addressing. 16 bit is an expression used for microcomputers with 16-bit microprocessors.
What are the 2 benefits of Packet-switching?
The Purpose of the IP Network Layer (3) of the OSI Model is to perform packet switching from one network to another. Packet Switching is a process of receiving a packet via a routed protocol on a single network and switching to another in such a way that a route to a destination can be reliably achieved (routing) via a routing protocol. Routing is processes of taking multiple network paths and by using an algorithm decide a metric which will determine the most reliable path a packet may take and store it in a table for future reference (routing table). Routing protocols like RIP use algorithms to generate and decipher a list of paths to any particular routed network. Information that is used in this determination includes hop count, reliability and link speed. Today it is widely understood that packet switched networks are superior to circuit switching. IP Multiplexing is more simplified than circuit switching and combines ability to route packets around failures which are measured and predetermined by routing protocols 24/7 365 days a year. One must however come to understand the inherent differences between routed protocols like IP and routing protocols like RIP to begin to develop a clear understanding of switched networks.
How many wires of cable cat 6 is use for data?
just one optic cable can carry a lot information to computers
What are the 5 companies that are using LAN?
Schools and/or small businesses such as self-employed or restaurants.
What is the role of Network Address Translation of IPv4 address space?
Network Address Translation translates and IP address used in a network to another IP address known within another network. A NAT table is maintained for global to local and local to mapping of IP's. NAT can be statically defined or dynamically translate from a pool of addresses. The NAT router is responsible for translating traffic coming and leaving the network. NAT prevents malicious activity initiated by outside hosts from reaching local hosts by being dependent on a machine on the local network to initiate any connection to hosts on the other side of the router
No - Transport layer protocols are not concerned with addressing packets to the correct system. (True)
Approximately how many ip addresses are available for a single class b ip license?
License? Where do you get this?
In a Class B network there are 2 to the 16th power addresses.
Class B = 255.255.0.0
65536 addresses
In a Class A network there are 2 to the 24th power addresses
Class A = 255.0.0.0
16,777,216 addresses
In a class C network there are 2 to the 8th power addresses
Class C = 255.255.255.0
256 addresses
Class A around 16 million
Class B around 65,000
Class C is actually 254 NOT 256.
IP addresses are leased and therefore the lessee is given a license to use that particular IP address.
What is subnet mask and default gateway?
Subnet mask is a mask used to determine what subnet an IP address belongs to.
Default gateway is the gateway in a network that a computer will use to access another network if a gateway is not specified for use.
The Presentation layer must make certain that the format of the data will be understandable by the Application layer. This includes the use of encryption, compression, different graphics formats, etc.
It uses a technique known as Portable Data Representation that allows data from different hardware to be able to communicate.
Is PC and laptop both are same?
Notebooks and Laptops are the same thing. Both words mean the same computer however a Netbook is where the difference is. A Netbook is usually a computer that has less hardware then the average laptop or notebook. Most Netbooks do not have a CDROM, they are smaller (7-12 inches) and they cost a lot cheaper then the average laptop.
Can you access internet through intranet?
An inhouse Web site that serves the employees of the enterprise. Although intranet pages may link to the Internet, an intranet is not a site accessed by the general public. For more info go to answers.com and type Intranet.
