TCP vs. UDP

TCP (Transmission Control Protocol) is the most commonly used protocol on the Internet. The reason for this is because TCP offers error correction. When the TCP protocol is used there is a “guaranteed delivery.” This is due largely in part to a method called “flow control.” Flow control determines when data needs to be re-sent, and stops the flow of data until previous packets are successfully transferred. This works because if a packet of data is sent, a collision may occur. When this happens, the client re-requests the packet from the server until the whole packet is complete and is identical to its original.

UDP (User Datagram Protocol) is anther commonly used protocol on the Internet. However, UDP is never used to send important data such as webpages, database information, etc; UDP is commonly used for streaming audio and video. Streaming media such as Windows Media audio files (.WMA) , Real Player (.RM), and others use UDP because it offers speed! The reason UDP is faster than TCP is because there is no form of flow control or error correction. The data sent over the Internet is affected by collisions, and errors will be present. Remember that UDP is only concerned with speed. This is the main reason why streaming media is not high quality.

Frame Structure

As data moves along a network, various attributes are added to the file to create a frame. This process is called encapsulation. There are different methods of encapsulation depending on which protocol and topology are being used. As a result, the frame structure of these packets differ as well. The images below show both the TCP and UDP frame structures.

TCP FRAME STRUCTURE

UDP FRAME STRUCTURE

The payload field contains the actually data. Notice that TCP has a more complex frame structure. This is largely due to the fact the TCP is a connection-oriented protocol. The extra fields are need to ensure the “guaranteed delivery” offered by TCP.

Sensor Networks

A sensor network is a group of specialized transducers with a communications infrastructure intended to monitor and record conditions at diverse locations. Commonly monitored parameters are temperature, humidity, pressure, wind direction and speed, illumination intensity, vibration intensity, sound intensity, power-line voltage, chemical concentrations, pollutant levels and vital body functions.

A sensor network consists of multiple detection stations called sensor nodes, each of which is small,lightweight and portable. Every sensor node is equipped with a transducer, microcomputer, transceiver and power source. The transducer generates electrical signals based on sensed physical effects and phenomena. The microcomputer processes and stores the sensor output. The transceiver, which can be hard-wired or wireless, receives commands from a central computer and transmits data to that computer. The power for each sensor node is derived from the electric utility or from a battery.

Potential applications of sensor networks include:

• Wireless Sensor Network (WSN) management
• Scalability to thousands of sensors
• Industrial automation
• Automated and smart homes
• Video surveillance
• Traffic monitoring
• Medical device monitoring
• Monitoring of weather conditions
• Air traffic control
• Robot control.

What Are VPNs and How Do They Work?

A VPN, which stands for Virtual Private Network, is a private network that uses a public network (like the Internet) to connect users together. VPNs can be used to send virtually any kind of data–voice, video, etc.– securely, using encryption. (It’s like a tunnel that establishes a “virtual link,” encrypts that data while it’s being transmitted, and decrypts it at its destination.) When using a VPN, you are hiding your IP address as well as your location.The network requires authentication, so that traffic between businesses and remote employees can flow without interruption from malicious hackers or spies. In a small office, VPN is usually implemented through a router.

Until the 1990s, computers were networked through leased lines or dial-up phone lines. But VPNs are cost-effective ways to maintain security over a network–and the cost isn’t dependent on the geographic location of the offices.

How Do They Work?

Remote-access VPNs work by connecting a LAN (local area network) to a remote user. A corporation that wishes to use VPN will usually outsource to an Enterprise Service Provider, or ESP. The ESP provides users with desktop client software for their computers. Large firms with hundreds of salespeople typically need this kind of VPN.

Site-to-Site VPN allows companies to connect fixed sites over a public Internet network. This can use some of the same software as a remote-access VPN.

There are two types of site-to-site VPNs:

Intranet-based VPN allows a company with multiple remote locations to join together in a single network, bringing together resources from one computer to another. This is a good way for companies to protect their local WiFi networks.

Extranet-based VPN allows business partners to connect LANs with LANs and allow companies to work in a shared environment while preventing access to their separate VPN spheres, or intranets.

What Are Your Options?

There are a few different kinds of protocols for VPN use. Here are the most common:

IPSec, or IP Security, is used to secure Internet communications. It’s normally used as a security overlay for the other protocols. It’s considered the “standard” VPN protocol, especially for site-to-site VPN.

PPTP (Point-to-Point Tunneling Protocol: PPTP)

PPTP is a method for tunneling that supports any kind of authentication process, and supports 40-but or 128-bit encryption. It’s included in the Windows OS, which is why it’s one of the most popular ones.

Layer 2 Tunneling Protocol typically requires a shared key, or digital certificates. It also protects against modification of the documents while they’re traveling, otherwise known as integrity protection for data trafficking. It supports IPSec, and can be used in both site-to-site and remote-access VPNs. L2TP VPNs are supported by firewall products like CheckPoint.

If you need secure access to your company’s network, VPN is your best bet.–but personal VPNs are necessary, as well. Since your ISP can store your private information for ages, and Wi-Fi hotspots are notoriously insecure, it may be worthwhile to purchase VPN service.

6 Tips to Avoid Facebook Viruses and Spam Messages

Facebook, the biggest social network with 500 million users, provides an interface to hit an unsuspecting crowd with malware and viruses. These viruses aren’t very difficult to detect  if you are cautious enough. These Facebook viruses appear on your wall in forms of a bizarre or eye-catching stories and videos and once the user has clicked/liked the link, it is already late. The next step will be getting rid of your Facebook virus which is a time-consuming  process.  Its better to avoid spam messages and trojan viruses in the first place.

How to avoid it?

1. Think before you Act. Viruses on Facebook are sneaky. The hackers and cybercriminals who want your information know that Facebook users will often click on an interesting post without a moment’s thought. If a post sounds a bit over-the-top like a headline out of a tabloid, this is your first warning sign.

2. Try to avoid Links and videos with Catchy words like  “funniest ever,” “most hilarious video on Facebook,” or “you’ve got to see this.” Do some keyword research to see if the post in question comes up in a search engine with information about a current virus or trojan.

3. Check the poster of the Suspicious content. If you receive a message from someone you do not know, this is an obvious red flag. Facebook video viruses also tend to pop up in your news feed or on your wall from friends you haven’t talked to in a while. Unfortunately, it’s likely this friend has already fallen victim to the latest virus on Facebook. After clicking on the story themselves, the message was sent out to all of their friends as well.

4 Avoid messages that have been posted by multiple users as the virus spreads among your friends who were not so cautious. If a link with title such as “Sexiest video ever” shows up all over your feed from all kinds of people (perhaps friends you would not expect to make such a post), this is another warning sign. Similar direct messages are a likely variant of the notorious Facebook Koobface virus which has used this approach in the past.

5. Do not fall for the “typical” money-transfer schemes. Chat messages from friends needing funds will usually sound suspicious. Everything can’t be screened before posting, so money transfer scams and hoax applications still find their way on to Facebook. You should also avoid applications that claim to do a full “Error check” or fix security problems related to your profile.

6. Update your anti-virus software frequently. If you do accidentally click on a post before realizing it is a hoax, do not click on any further links or downloads. If it’s too late and you have already been infected, the Facebook virus removal process may be effortless if you have a good anti-virus program to catch the virus, trojan or other malware early on.

What’s Next?

These were few important tips to safeguard your facebook account but your job isn’t done yet. Once you have detected that the link/post on your facebook wall is Malicious you should Mark it as SPAM so that the facebook support will stop it from spreading further and infecting other users.

If you have ever fallen victim of any such Malicious Scheme, please share your experience with all the users  in form of comments so that others don’t fall victim of it.

Create Your Own Search Engine

1. Open website  http://www.funnylogo.info/create.asp

2. Enter your Search Engine name

3. Select style as per u like

4. Click on create my Search Engine

5. Finally you got your own Search Engine

Note: Actually mechanism is there that you have only replace Google name with your own rest of remains same.

Create and Send Fake SMS To Your Own Mobile Free (Even In Offline Mode)

How about creating any message (From any name and number you choose) in your (Or any other) mobile and send it to your own inbox and that too without any network and operator (In offline mode, no SIM required)??? Impossible? No, actually it is easier than sending a real SMS. This is called a fake SMS, a prank that will astonish even an unaware mobile expert. Sometimes for fun and sometimes to make someone believe something, this trick is awesome.

So to get started, you need to have Active File installed in your Symbian S60 phone (Download from HERE). Active File is a free file explorer app (Just like X-Plore and FExplorer) for Symbian mobiles (All editions and versions). Besides, Active File can do a whole lot of other things as well.
Now to create and send a fake SMS, run Active File and go to “Options/Tools/Create fake SMS” (Here you can set parameters like sender’s name, mobile number, text of message, date, time, number of times sms will be sent, set as read status and target folder (Inbox, Outbox, sent, draft).
Fill the required fields and go to “Options/Create”, simple and yo!!! Your message tone will ring up the next moment (Or at the set time) and a “genuine” SMS (That you just created yourself) will flash as a “1 new message”. There is no way theses messages can be distinguished from other SMSes. Now time to have some fun with your friends.
NOTE: This app is available only for Symbian S60 phones (S60v2, 3 and 5), so no luck for other OS phones (Java, Windows mobile, iPhone, Blackberry, Android etc).

SATA HDD Multimedia Player Adapter

Manufacturer Brando presented quite an interesting adapter for SATA hard drives. Hard disk format 3.5 or 2.5 inch can be connected with the device and it turns into a USB-drive and at the same time in a media player device. It can be connected to a TV or computer display via HDMI cable, media player is able to show the screen format of 1080i (up to 1920 × 1080) through its own application to play the files. In addition, the device has a USB 2.0 port, which allows to get information from the flash drive or pass on information to them from the hard disk. It has slot for cards format SD / SDHC to serve the same purpose. The embedded media player supports playback formats i.e. MPEG, AVI, MP4, VOB, and DivX. Its Price is $ 69, Package includes are;  the SATA HDD Multimedia Player Adapter, remote control, USB-cable and a universal power supply.