Client and server communicating over DCCP

Abstract —We show that the Datagram Congestion Control Protocol (DCCP) provides ∼ 10% – ∼ 40% greater energy ef- ficiency than the User Datagram Protocol (UDP) in a wireless LAN (WLAN) client. Our empirical evaluation uses a testbed comprised of consumer components and opensource software to measure typical performance that can be expected by a user, rather than highly-tuned performance which most users will not be able to configure. We focus our measurements on a scenario using IEEE 802.11n at 5GHz as energy efficiency will be particularly important to mobile and wireless users. We consider overall performance as well as the energy efficiency of the protocol usage to give a rounded comparison of UDP and DCCP. Overall, we see there would be great benefit in many applications using DCCP instead of UDP.

• Security – Only authorized users can access your application data, while allowing your customers to securely access the data they need. Conduct Business over the Web MAS 90 or MAS 200 and the e-Business Manager module can supply an out-of-the- box solution to transact business-to-business e-commerce, worldwide, over the Internet.

In this research, we show the results of TCP, UDP and DCCP protocol using NS3. NS-3 supports a graphical tool gnuplot. All the graphs are generated by gnuplot to show the results of NS-3 simulation for each protocol. We give the graphical analysis of the protocol performance metrics like delay, throughput, Packet Delivery Ratio and packet loss. We have shown previously that the network topology consists of three parts. The mobile unit call (Ue) which is communicating directly with base station, the Base Transceiver Station (BTS) also calls Evolved Node B, (abbreviated as eNodeB or eNB) and the end terminal which is server in our scenario. This server receives the packets from mobile units. In order to measure network performance we have created three different scenarios 10 Ue, 20 Ue and 30Ue connect directly to one eNB and the eNB connected to server node.

Previous Settings Graph : Provides a quick way to view the local computer’s clock accuracy over time. The chart shows the time adjustment, in seconds, made at each setting recorded in the log file. As with the Current Settings graph, the vertical axis shows the time difference, which is the amount of time, in seconds, the internal clock was off from standard time. The horizontal axis shows the time settings for the date or time of the actual setting. The Clock Drift and Previous Settings graphs rely on data from a log file, which ClockWatch establishes by default. The ignore zero settings option suppresses settings where the time was in sync and displays settings (in 3D) where a time change was made on the local computer. Data are displayed from the last setting made on the previous run of ClockWatch backward toward the first setting. Increasing the number of data points shows earlier data, if available. Notes on the Graphs

FTP (file transfer protocol) FTP is a standard protocol used for transporting files from a server to a cli- ent over the Internet. Grayware Files and programs, other than viruses, that can negatively affect the perfor- mance of the computers on your network. These include spyware, adware, dialers, joke programs, hacking tools, remote access tools, password crack- ing applications, and others. The OfficeScan scan engine scans for gray- ware as well as viruses.

The distributed object implementation of client/server computing is going to change the way applications are built. There should be some very interesting advantages to observe. For one, if we needed fault tolerant computing, we could implement copies of objects onto multiple servers. That way if any were down, it would be possible to go to another site for service. With distributed objects being self contained and executable (all data and procedures present) it will be possible for a systems administrator to tune the performance of the network by moving those objects from overloaded hardware to underutilized computers. This approach is called tuning through “drag and drop”, referring to the metaphor the administrator uses on a workstation to move the components.

1 M-Tech in Electronics Design and Technology, National Institute of Electronics &Information Technology Aurangabad, Maharashtra 2 Scientist ‘B’, National Institute of Electronics & Information Technology, Aurangabad, Maharashtra ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract – The Internet of Things (IoT) is a rapidly expanding technology that is shaping up to bring the next revolution in computing and information technologies IoT has wide range of applicability in industries and it is flexible in any given environment. In recent years with the development of Internet technology, the Internet of things (IoT) has begun to apply to each domain. In the era of IoT, the proliferation of devices such as RFIDs, actuators and sensors has enabled a specific paradigm. Smart devices are used effectively in the environment to monitor and collect ambient and resourceful information. This project introduced the idea of how to apply IoT to AGV’S (Automated Guided Vehicles). These vehicles are mainly useful for material handling and floor transportation purpose. The AGV automated guided vehicles have huge demand in the manufacturing industry. IOT based AGV, is connecting the AGV with the help of internet which is part of industrial 4.0. The vehicle has different sensors installed in it, it does not only introduce the idea to analyze, process and store the sensors data but also transferring real-time data using IoT. Due to this noteworthy feature, a user can view each specific sensor data and it’s visualization with the help of the web server system.

Recall that for each access, we must extract the prin- cipal, the object, and the access type. The principal and access type are easily extracted from NFS client requests. Extracting the name of the object being accessed is more difficult, requiring the mapping of an NFS handle to a pathname. Fortunately, Ethereal already implements the logic necessary to extract such mappings from requests such as LOOKUP and the corresponding replies and maintains them in a hash table. Evicting entries from this table can be difficult, however, because NFS versions 2 and 3 use persistent file handles. Any eviction may cause our system to not have the necessary mapping to evaluate a future request. Currently, we evict mappings that have not been used for a threshold amount of time despite this problem. If the system ever receives a request containing a handle that cannot be mapped, it returns a stale handle error, which becomes visible to the user. NFS version 4 allows the server to limit the use of a handle to some finite period, which solves this problem.

This application note describes the process users should follow to perform a ZigBee over-the-air (OTA) bootload cluster download between a client and server device, and how to perform an Ember Standalone one-hop bootload. The instructions show an Application bootloader for a Smart Energy 1.x devices, while the Standalone Bootloader uses a Home Automation 1.x device. The hardware used in both cases is Ember® EM35x development kits. Users can also refer to this procedure when setting up or testing OTA bootload downloads in their own development environments with their own hardware.

Multiuser one-tier applications are okay until the number of users gets large. The problem is that all the database work is performed in each client. For example, if the program needs to list all clients with the last name of Smith, all the information (indexes and data records) needed to resolve that query to the database must be transferred over the network. For some complex queries, a significant amount of data must be examined, perhaps even the entire database. At a more technical level, it is difficult to manage independent database engines to be sure that no conflict arises when two clients attempt to access or update the same record. This is called the record-locking problem.

Even though SSL provides secure communications between Web servers and browsers on the Web, it cannot protect against end-system threats. For instance, if a user receives attributes from the server over a secure channel, it does not mean that we can trust the user. In other words, once the user, let's say Alice, receives some attributes from the server over the secure channel, she is able to change the attributes or give them to other people, because SSL does not support the integrity service in the user's end system. Then, Alice (or the person impersonating Alice) can access the servers - which accept the attributes - using those forged attributes. However, as we will see later in this paper, SSL can be used as part of our solution to protect information on the Web.

One example is where a simple query, constructed by the application, allows wild-card searches to be performed. Forms-based applications usually fetch only the data that can be displayed on the screen. However, on a workstation, it is quite common for the application to fetch all the data in the query and store it in arrays for later use. Not only must the database fetch all the table rows, the data must be transferred over the network, and the workstation must allocate large amounts of memory (with consequent paging onto disk) to process the query. Although the user may only ever see the first few rows displayed, very large amounts of network, server and client resources are used and the response time is slow.

Sample closing paragraph in client-advice letter (external client; litigation context):.. “In conclusion, if we were to file a motion to include a jury instruction on self-defense, I b[r]

The paper considered two mitigations, CCID4-FR and CCID4-QS. Even though these variants provide faster access to network capacity and therefore improve the performance of bursty VoIP traffic, there are still issues that need to be addressed. Jitter is small when the VoIP traffic is encoded using a constant rate codec, but increases for bursty VoIP traffic using silence suppression. Sender buffering policy is also a significant factor impacting user performance for bursty traffic sources (such as speech with VAD). These issues im- pact performance, particularly for high-delay paths, including satellite links, and demand further development of the DCCP transport protocol interface and CCIDs.

However, DCCP encounters challenges while adapting to the wireless network environment. The congestion control schemes of DCCP suffer inappropriate sending rate reduction because of the following two main reasons. Firstly, the situation of wireless congestion occurred on an Access Point (AP). It means that the allocated channels on the AP are in a highly competition status. In this situation, the total amount of required bandwidth that is needed from the connected mobile nodes may exceed the capacity of the AP. Therefore, incoming packets should be temporarily stored in AP’s buffer. However, if the arrival rate of incoming packets exceeds the service rate of the AP, AP’s buffer may be overflown and some packets should be dropped. It is the so-called wireless congestion that leads to significant performance bottleneck during transmission. Secondly, the situation of signal fading error occurred during transmission over wireless networks. Signal fading error results from the attenuation of signal strength and the effect of multipath fading. The signal fading error affects the integrity of packet delivery and then degrades the transmitting throughput. When the situation of signal fading error occurs, some segments of transmitted packets cannot be successfully received on the mobile node, and packets are dropped by the node.

The server enables many clients to share access to the same database and enables the use of a high-performance computer system to manage the database.. Client/Server Applications.[r]

A. Title Client/Server Technology B. Introduction Client/server is a network architecture that divides functions into client and server subsystems, with standard communication methods to facilitate the sharing of information between them. A client is defined as a requester of services and a server is defined as the provider of services. Client/server computing [2] is a very efficient and safe means of sharing database information in a multi-user environment. The client program usually accepts user requests and provides screen displays. Server programs generally reside on more powerful machines and are used to process information. A single machine can be both a client and a server depending on the software configuration. When client-server programs are on different machines, the client and the server machines are linked together through a network.

A final issue is whether to expose the asynchronous nature of com- munication to clients, thus enabling some performance optimizations. Specifically, typical RPCs are made synchronously, i.e., when a client issues the procedure call, it must wait for the procedure call to return before continuing. Because this wait can be long, and because the client may have other work it could be doing, some RPC packages enable you to invoke an RPC asynchronously. When an asynchronous RPC is is- sued, the RPC package sends the request and returns immediately; the client is then free to do other work, such as call other RPCs or other use- ful computation. The client at some point will want to see the results of the asynchronous RPC; it thus calls back into the RPC layer, telling it to wait for outstanding RPCs to complete, at which point return arguments can be accessed.

Name: Date: Quiz 3: Load 2008 Server, LAN Setup, Driver Load, Windows Update, Windows Defender, Active Directory, Organizational Units, Groups, Password and Lockout Polices, Joining a Domain, Wireless Networks, Adding Users, MMC, Remote Desktop, Building and Setting up a Client Computer, Build a WDS Server, OS X Clients and Trusts.

RTQ runtime management system architecture. RTQ is used to process transactions that do not require immediate processing. A foreground application submits transactions to the RTQ Server and a background application processes queued transactions with the RTQ Worker. Queued transactions can be processed at a scheduled time or in a trickle-feed fashion. For example, to increase data protection an application can commit database changes to a regular database and to RTQ. RTQ will later forward these updates to an alternate (possibly off-site) database.