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About Cisco NetFlow

Cisco NetFlow is a Cisco developed flow technology that allows bandwidth monitoring of a network. NetFlow Analyzer is a software that uses Cisco NetFlow to monitor bandwidth and runs in windows and linux. Cisco routers/switching devices export NetFlow as UDP packets. Cisco NetFlow is one of the flows, among other flows, that is used to monitor bandwidth in the network. These Cisco NetFlow packets can be analyzed using NetFlow Analyzer, to monitor bandwidth, to gather information on the top talkers, applications and many other features. Network traffic analysis is one of the uses of NetFlow Analyzer. NetFlow Analyzer delivers easy-to-understand reports on in-depth traffic analysis and network bandwidth monitoring.

Cisco NetFlow allows for extremely granular and accurate bandwidth monitoring by recording network traffic into the device cache. Since network traffic has a flow nature to it, the NetFlow accounting data that is built in the cache, characterizes the IP traffic being forwarded. Various screen shots of the network traffic report that can be generated using NetFlow Analyzer have been given here.

Cisco NetFlow data records exported by routers and switches consist of expired traffic flows with detailed traffic statistics useful to monitor bandwidth and network traffic analysis. These flows contain information about source and destination IP addresses along with the protocols and ports used in the end-to-end conversation.

This exported NetFlow data is collected and analyzed by NetFlow Analyzer to generate reports on top hosts, top applications, top conversations and top talkers using the bandwidth in your network.

Cisco NetFlow combined with NetFlow Analyzer yields valuable information about the behavior of traffic and bandwidth monitoring on your network. Armed with this information, it is easier to make critical decisions on bandwidth capacity, security, and optimal usage of network infrastructure.

NetFlow traffic statistics
The latest version of NetFlow Analyzer supports Cisco Netflow version 5, version 7 & version 9 exports.

While NetFlow version 5 is the most used version supported on routers, NetFlow version 7 is an enhancement that exclusively supports NetFlow with Cisco Catalyst 5000 series switches equipped with a NetFlow feature card (NFFC). NetFlow version 7 is not compatible with Cisco routers. NetFlow version 9 is the recent addition to the series.

VPN Connections

The initials “VPN” in the computer industry stands for “Virtual Private Network” and this is actually a physical framework constructed using the actual PC and its connecting wires to effectively establish several nodes of computing machines within a network. This system uses several advanced security measures such as data encryption techniques to ensure that only those authorized users are able to access and view the associated data found on the established network. This type of network is basically what is meant when mention is made as to a virtual or a private connection.

VPN is one form of “WAN” or the “Wide Area Network” and it is capable of supplying a network of connectivity which can stretch for very wide physical distances such as through the use of the World Wide Web or by use of an intranet. Both of these are commonly employed network capabilities established by major companies and corporations for use by its staff and executives. Data file sharing, voice or video conference transfers as well as other network services similar in nature are made possible by way of the VPN.

The VPN is able to work both in the private mode as well as in public networks such as the internet. This is accomplished though the use of a method referred to as “tunneling”. While “tunneling” still makes use of the same hardware infrastructure of the computer system such as the existing intranet or internet link up features it has its own unique manner of operation as well. As mentioned previously, it has the capacity to protect your private connection and thus your personal data through several effective security systems and safety mechanisms. Security for major corporations is of prime concern when establishing these data transfer systems. There is no acceptable excuse for weak or ineffective security when it concerns personal and business data thus only those proven methods and systems are acceptable.

VPN can be employed chiefly in three different types of communication modes. The first mode is merely for accessing the internet itself. The LAN to another LAN networking is the second communication means and lastly it is able to function within a controlled environment such as a privately set-up intranet structure. Just recently, many corporations and companies have begun to explore the possibility of increasing mobility among its key executives and important staff members. With this move towards a mobile structure the VPN has taken on a new and elevated position of importance. With the vast development in telecommunication the VPN function has proven to be very useful for people that desire to remain connected even when considering the huge differences involved in physical distance. As a result of these advanced planning initiatives productivity is not compromised by distance in the least.

YouTube自动字幕限英文对所有用户开放

CNET科技资讯网3月9日国际报道 Google上周宣布，YouTube的自动字幕(auto-captioning)功能开始对所有使用者开放，希望能让视频更容易观赏并通过搜索引擎搜索。

　　Google在记者会上表示，自动上字幕的功能不只是对听障者有帮助，也是外国人学习英语的好帮手。

　　视频提供者如今可申请让自己的视频添加机器转译的字幕。即使视频原本未加上字幕，使用者也可自行要求上字幕，接下来YouTube会把视频加进等待上字幕的名单，可能费时一小时或一天不等，未来速度可望加快。

　　用来作自动字幕的技术，与Google的Voice Search脱胎自同一个架构。不过，发言人表示，视频与语音的挑战截然不同，Voice Search通常自电话撷取声音，一般来说这些声音可能已去除了噪音，而且只有一个说话者；但视频里可能同时有多人说话，而且可能是南腔北调，还有背景杂音的问题。

　　这正是Google还在继续设法克服的挑战，另外还有支持非英语口语的挑战。目前自动字幕只以英语视频为限，不过Google可用自家翻译服务把自幕转译成其他语言；目前Google翻译服务支持50种语言。

　　先前字幕功能已对部分使用者开放，即日起应可进一步对所有使用者开放。

分析师：索尼PS3将是这代游戏机最终霸主

尽管任天堂的Wii目前依旧是最热卖的游戏主机，索尼的PS3只能苦苦追赶，但独立调研机构Strategy Analytics近日发布的报告表明，PS3才将是这代游戏机的最终霸主。

Strategy Analytics认为，任天堂的Wii的最鼎盛时期已经过去，其销量将从2011年开始下滑；而索尼的PS3和微软的Xbox 360却还在增长，并预计索尼PS3将在2013年成为全球最大的游戏平台。当这代游戏机寿终正寝时，索尼PS3的累计销量预计将达到1.27亿部，而任天堂Wii则为1.03亿部。

分析师David Mercer表示，任天堂Wii吸引了不少新玩家，但是他们的销量开始呈现下滑趋势，特别是在成熟市场。Wii的销量将在2011年开始下滑，而索尼PS3和微软Xbox 360到2012-2014年时才会达到其销售峰值。

此外，Strategy Analytics认为加入索尼动作感应器的加入以及向3D功能的升级都会帮助PS3销量的增加。

对于今年的游戏机市场，Strategy Analytics预计整体销量将会同比下降9%。任天堂Wii还将以1750万销量继续领跑，索尼PS3将以1400万排名第二，微软Xbox 360将卖出1050万，索尼PS2也会有550万的销量。

USB Flash drives

Roughly, a USB flash drive is a device to store data in a flash memory with a USB interface integrated on it. This way the memory will be rewritable and also removable as a disk, but it is much smaller, will weigh much less and it is more comfortable to carry.

The storage capacity if a USB flash drive can vary a lot. They range from some mb to up to 256gb and every day passing they are larger and cheaper. The best USB flash drives allow to up to 1 million of cycles ( the times you can erase and write them) and may store the data with no errors for years.

The main function of these USB flash drives is the same intended for floppy disks in the past, but the advantage is that they are much smaller, the capacity is much higher and they are safer and more resistant. A typical USB flash drive won’t break if it falls to ground and will not get scratches as a common CD or DVD. At it is very little it can be stored in a pocket.

USB flash drives have a limited write / delete life so it is not recommendable to waste their life with unnecessary procedures like defragmentation. USB flash drives may be defragmented but it is barely useless because there are no mechanical parts in the drive and thus no mechanical head will move from a fragment to another. It may offer a little advantage because will need to access to less sectors but doing so will shorten the life of the flash drive in a great amount.

A USB flash drive can be partitioned as a Hard Drive but again it has little utility because installing a system in a USB flash drive will make too much writes and deletes and the life of the drive will be shortened.

The main disadvantages of an USB flash drive are for example the limited number of cycles before the device will fail. This may be considered if you plan to use a USB flash drive to run software or to use it as an OS. Another great disadvantage is that most USB flash drives do not include a write protection switch and thus, they are sensitive to be infected with a virus very easily. Their size is very convenient but on the other hand it is very easy to misplace them or leaving them behind.

About the price, they are very expensive if we compare to HD’s in the per unit storage cost, but when it comes to small capacities like for example a 8gb drive, they are much cheaper than a 8gb HD. They are very convenient for small capacities and to be used to carry personal data at all times like pictures, music, videos, resumes, documents and even medical information in the case of an accident because of their high resistance to water, impact and other inconveniences although they are not designed for this purpose.