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I am often asked the difference between KBps and Kbps,here is the answer:

In data communications a Kilobit is one thousand bits. It is used to measure the amount of data transferred per second. Kilobits per second is shortened to kb/s, Kbps or kbps (as opposed to KBps, which is Kilobytes per second. Note the capitalization.) The lowercase b is commonly used to denote bits, while the uppercase B is used for bytes.

bit: minimum unit that handles a computer. (zero a one).
byte: it is a set of 8 bits and represents a character.
bps: (bit per seconds) unit of measurement of information transference.
bytes/s: (bytes per seconds) unit of measurement of transference of information in byte per second.

1 KB/s = 1024 bytes per second
1 kb/s = 1000 bits per second
1024 kb = 1 mb (megabyte)

Tags: bit, byte, bytes, KBps

NAT stands for Network Address Translator.

Network address translation (NAT) is the process where a network device, usually a firewall, assigns a public address to a computer (or group of computers) inside a private network. The main use of NAT is to limit the number of public IP addresses an organization or company must use, for both economy and security purposes.

It is proposed and described in RFC-1631 and is used for solving the IP address depletion problem. Basically, each NAT box has a table consisting of pairs of local IP addresses and globally unique addresses, by which the box can “translate” the local IP addresses to global address and vice versa. Simply put, it is a method of connecting multiple computers to the Internet (or any other IP network) using one IP address.

The most common form of network translation involves a large private network using addresses in a private range (10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, or 192.168.0 0 to 192.168.255.255). The private addressing scheme works well for computers that only have to access resources inside the network, like workstations needing access to file servers and printers. Routers inside the private network can route traffic between private addresses with no trouble. However, to access resources outside the network, like the Internet, these computers have to have a public address in order for responses to their requests to return to them. This is where NAT comes into play.

Internet requests that require Network Address Translation (NAT) are quite complex but happen so rapidly that the end user rarely knows it has occurred. A workstation inside a network makes a request to a computer on the Internet. Routers within the network recognize that the request is not for a resource inside the network, so they send the request to the firewall. The firewall sees the request from the computer with the internal IP. It then makes the same request to the Internet using its own public address, and returns the response from the Internet resource to the computer inside the private network. From the perspective of the resource on the Internet, it is sending information to the address of the firewall. From the perspective of the workstation, it appears that communication is directly with the site on the Internet. When NAT is used in this way, all users inside the private network access the Internet have the same public IP address when they use the Internet. That means only one public addresses is needed for hundreds or even thousands of users.

D-Link´s broadband routers (ie: DI-604) support NAT. With proper configuration, multiple users can access the Internet using a single account via the NAT device.

Tags: DI-604, NAT, network address translation

D4D Technologies is a high tech medical device company offering state-of-the-art 3D digitizing applications that take the dental profession to a higher level of productivity, patient comfort and convenience with its E4D Dentist CAD/CAM restorative system. This cutting edge technology enables dentists to scan, design and mill a permanent crown for patients in about an hour, without the need for outside lab work and multiple appointments.

The Challenge

Nobody likes to spend any more time than necessary in the dentist’s chair but having to wait days for a crown is cruel punishment. D4D Technologies, based in the Dallas area, provides state of the art 3D dental imaging system that offers dentists and their patients the convenience of creating permanent crown on demand. This innovative system employs lasers, custom optics, 3D rendering, real-time computing and robotics. It is being utilized by dental practices worldwide, including in the US, Canada, Australia, New Zealand, South Africa, and will be launched in Europe.

E4D system consists of three elements. First, a mobile device with an intraoral scanner (IOD) presents the treatment room. The IOD is an included high-speed computer with proprietary software and a 17 LCD. The dentist uses a tool to draw around a crown preparation necessary to create accurate, real-time digital later for optimum fit.

Next, the digital image of the tooth is sent wirelessly and securely to the job server – a desktop computer that computes a tool path from the scanned data. Finally, the tool path data file is transferred to a milling unit that interprets the image and mills the crown.

The critical link is the wireless connection between the IOD and the job server. A dental office typically has a lot of digital “noise” including electronic equipment, physical obstructions and other interference that can hamper the signal and slow or stop communications. Dentists prefer the IOD unit to be wireless so it can easily be moved throughout the office. D4D requires a powerful, yet reliable wireless solution to assure the system runs smoothly and without interference.

The Solution

“You can design a beautiful tooth, but if you can’t get it to the job server the whole process is moot,” said Mark Lazarow, IT manager of D4D Technologies. Mark consulted with Jeff Romick, Vice President of HBR Technologies, a D-Link reseller also in the Dallas area that specializes in security, mobility and healthcare solutions.

D4D Technologies and HBR Technologies partnered with D-Link to perform a rigorous test of their secure wireless products. “We opted for the D-Link® DIR-655 Xtreme N® Gigabit Router with three antennae because it had better reception, data transmission and failure rate. We paired it with the DWA-160 Extreme N Duo adapter,” he said. “Now the system can handle large file sizes in a complex environment that has a lot of transmission noise. Plus it provides complete security and meets HIPPA (patient privacy) requirements.”

Another key component of the D4D imaging system is providing outstanding customer support. It is critical for the company to be able to access its dentist’s computer via the Internet to monitor in real-time and troubleshoot problems. “We needed a router that would maintain a signal and be reliable so we can access our customer’s computers at any time,” Lazarow said.

“The D-Link routers provide us with a more reliable signal and the transmission speeds are three to four times faster than before,” he said, adding that they have deployed more than 700 D-Link router/adapter combos in dental offices worldwide.

“You just can’t mess around when you have a patient in the chair. You have to be efficient,” said Lazarow. “D-Link helps let our dentists do that.”

Tags: 3D, D-Link, D4D, DIR-655, DWA-160, HBR, IOD, Solution

If you computer is Windows XP:

Step 1: Click Start > Control Panel.

Step 2: Double-click Add/Remove Programs.

Step 3: Click Add/Remove Windows Components on the left side.

Step 4: Please wait while the list of Windows Components loads.

Step 5: Scroll down to Networking Services. Select Network Services and click Details.

Step 6: Check Universal Plug and Play and then click OK.

Tags: Network Services, UPnP, Windows XP

Virtual Server – is used to forward a specific external port to an internal port in a one port to one port relationship. This would allow WAN side connections to come to the LAN side of your network. Virtual Server settings are commonly used for Port Redirection, when you use a public port that is different from the private port. This use is common if you are accessing multiple cameras. For for ease of use, you keep the cameras all on port 80 to view the web interface, but because the router will only allow port 80 to be opened to one IP, you would use Virtual server to redirect other ports to the LAN side cameras on port 80.

Example: In Virtual Server you would set your first camera as public port 81, private port of 80 and set it private IP accordingly. Then make the second camera public port 82, private port 80 and set its private IP accordingly. Internally (from LAN) both camera can be accessed at their IP address and port 80. From the outside(from WAN) they are access from the WAN ip address and their respective Public port, camera one at 81 and camera two at 82. http://wan-ip-address:81 typed into your browser will show you the web page of camera one.

Port Forwarding – is used to allow data to come from the WAN (Internet) and pass through the firewall to the destination ip address(s). This is used when a device or application behind the firewall of your router needs access to a range of ports to function properly. (E.g. online games or gaming consoles, FTP servers and network cameras.)
However, no two devices or machines on the LAN side of the router can use the same port number at the same time.

Example: In the case of the camera above, for Virtual Server, you kept the HTTP port as 80 and used Virtual Server to make the public port 81. To cover the streaming ports, Audio, Video, and control (DCS-5300G) you will have to set each port range unique to each camera and put those ranges in Port Forwarding. You can keep 5001-5003 for camera one but need to make camera two unique, may be 5004-5006.

In the end you will have used the Virtual Server for redirection and the Port Forwarding rules to allow a range of ports through the router to a LAN side device.

Tags: Port Forwarding, Virtual Server