Mobile & Remote Video Surveillance

Mobile & Remote Video Surveillance Camera Systems

Customers often ask how to access a live view of their remote security cameras when they’re away from their home or business. After all, people lead busy lives, come in and out of work, go on vacations, and run errands so investing in a remote video surveillance system is crucial to the well-being and safety of your home or business. Thus, much of the time you’re not actually able to be onsite where your cameras are installed. One of the primary benefits of IP video is that you’re not limited to viewing your remote video surveillance system on site. The advancements in video surveillance technology have made it possible to view your remote security camera from any internet-enabled PC or smartphone. arindamcctvaccesscontrol.blogspot.com has outlined the key components of remote security camera system and video surveillance app, everything you need to know in order to start viewing your security cameras off-site.

What is Remote Video Surveillance?

Remote video surveillance enables users to view live video on a PC or laptop from just about anywhere in the world with internet access. To facilitate remote viewing, you simply type in the IP address of your network security camera in your internet browser like you would a website. This is done through DDNS and port-forwarding, which is discussed in greater detail further below. Once you’ve configured DDNS and port-forwarding and have obtained an IP address to view online, you can then begin to experience what it’s like to view your security camera system from a remote location. Remote security cameras are typically compatible with a wide range of web browsers. It is worth noting that specific web browser support varies by manufacturer.

What is Mobile Monitoring?

Remote mobile video surveillance takes remote monitoring to a whole new level. Several IP camera manufacturers offer complimentary mobile surveillance apps that give you the ability to view and manage your security cameras from a smartphone or tablet such as the iPhone, iPad, or Android. Many of these security camera apps allow you to view multiple cameras simultaneously, control PTZ settings, view recorded images, search through archived footage, play back events, and much more. Just like you would view your security camera(s) on a remote PC/laptop, you will need to have an internet data plan and IP address to do so. Remote video surveillance is perfect for users who are often off-site, and therefore not able to be on the local computer system where their IP cameras are connected.

What’s the Difference between Remote and Mobile Video Surveillance?

The common denominator of remote monitoring and a security camera app is online viewing. The main differences between the two are usability features. Remote monitoring tends to give you greater control over your camera system when it comes to managing settings and recording video. If you’re checking up on your business cameras from your home or hotel on a PC or Mac, you usually have a more reliable and secure internet connection.

A mobile security camera app requires a smartphone data plan, and may lose connection from time to time in no-coverage zones. It’s also a matter of personal preference – if you use the internet primarily on your smartphone, then mobile surveillance may be the right choice for you.

How can Remote Video Surveillance and Mobile Monitoring Help You?

Remote security camera monitoring and mobile surveillance do not require you to be “on location” in order to view and manage each of your security cameras. You’re not limited to monitoring just one camera remotely; most video surveillance apps provide simultaneous viewing and multi-site options so you can check up on all of your remote security cameras in your business or home. Monitoring off-site is also extremely convenient for users as it gives them the freedom to come and go as they please without having to worry about their property. For example, mobile and remote monitoring is great to have when you’re on vacation. If you’ve got two or three IP cameras installed at your home, and decide to take a trip somewhere, you can still monitor your property and receive email notifications if your cameras detect motion or tampering. Essentially, remote video surveillance makes it so you don’t have to be at the exact location of your security cameras to keep a watchful eye on your property. In addition, remote monitoring works wonderfully with pet cams, nanny cams, and pool cams. You’re not limited to what you can view. Surveillance on the go has never been easier.

Features:

View Live Stream - Real-time video display is a primary selling point for remote and mobile monitoring. Having direct access to your live camera feed gives you the power to monitor your property without actually being there.

View NVR Live Stream - Some NVR manufacturers offer remote web interfaces and video surveillance apps that provide remote access to your IP camera system. These Internet-based platforms give you instant access to live camera displays and recorded video footage that work on PCs, and some smartphones. You simply log on to the NVR’s web interface or app to facilitate real-time monitoring.

View Recorded Video from your camera/NVR - Another benefit of remote monitoring and mobile surveillance is with some mobile apps and NVR web interfaces, you can view recorded video. This is especially helpful when you’re on vacation; you can review recorded video and decide if it’s relevant or not, or notify law enforcement if you come across something suspicious that was captured on video.

Images are sent to your phone, on motion or schedule - You can configure your IP camera so that images are sent directly to your email account or smartphone via message MMS if motion, tampering, or vandalism is detected. Images can also be sent on a schedule to keep you abreast of what your video monitors.

Send images to email account - With video management software, you can configure your security cameras to send email alerts to your smartphone, iphone or email account for evidentiary purposes and as a way to archive footage deemed important.

Administer VS System remotely - You can do a lot more with mobile and remote monitoring than just viewing live video. A number of IP camera and NVR brands offer web interfaces and cloud services that can be accessed from remote locations. These online platforms allow you to control the settings and configure your IP camera system like you would onsite.

How Do You View Your Video Surveillance Cameras Remotely?

In order to monitor your video surveillance cameras from a remote device like a PC or smartphone, you will typically need to set up DDNS and port forwarding.

DDNS - With video management software, you can configure your security cameras to send email alerts to your smartphone, iphone or email account for evidentiary purposes and as a way to archive footage deemed important.

Port-Forwarding - When you purchase your IP camera system, you’re at first limited to viewing your cameras locally, meaning you can only access them in a local area network. To view your cameras remotely, you must configure port-forwarding. Port-forwarding sends network ports used by your IP camera(s) onto the World Wide Web so that you can monitor your cameras remotely. Network ports are typically forwarded through your network’s router, which tech support specialist at VideoSurveillance.com can help you with. Port-forwarding can only be set up by obtaining the IP address of your router that connects to your video surveillance cameras. It should be noted your IP cameras and NVRs are still secure when accessed via the Internet because of password protection.

Special Plug-and-Play Solutions - Some NVR manufacturers such as Smartvue offer online cloud services that allow you to access your video surveillance system from a remote location by simply logging into your cloud account. Once logged in, you can view your live video feed, manage settings, and search recorded video as needed.

Benefits Of Remote Surveillance Monitoring

24/7 Protection

One of the more popular benefits of a modern surveillance system is the ability to monitor footage remotely with a mobile app. There's a wide array of apps that allow a user to log into your system from anywhere with just a touch of your smart phone. Upon logging in, you will have the ability to view live and recorded video, control PTZ settings, search through past footage and manage alerts. To set up the app properly, you'll need to work closely with a security company and have an internet data plan as well as an IP address.

The best aspect of this feature is that you don’t have to be on location to view and manage your security cameras, thus offering you and/or your security staff the ability to monitor and respond to issues whenever they may occur, even after hours or while you are on vacation. The added peace of mind that comes with remote monitoring can be the greatest benefit of all.

Monitor Multiple Feeds Across Multiple Locations

Also, you don’t have to be limited to monitoring only one security camera remotely. If your building requires multiple cameras in seperate locations, you're in luck as you can monitor multiple camera feeds from across multiple locations. This is a popular feature for property managers who need to monitor multiple buildings.

This is incredibly useful when combined with a motion alert camera system-- you can be alerted if any of your cameras detect motion while your business is closed. In addition, you will get an email and/or text alert notifying you that one of your cameras detected motion.

Less False Alarms

The overriding advantage associated with a remote monitored system is the fact that it provides visual confirmation to an operator regarding the cause of anyone specific activation. In turn, this lessens the likelihood of false alarms and allows the operator to orchestrate the fastest possible and most appropriate action.

When an alarm is triggered, the process begins and the images are transmitted to a central control room where the operator consults site plans to determine whether to issue audio warnings or alert the relevant emergency services. Audio warnings have been proven to act as a successful deterrent for a majority of cases, in terms of contacting the emergency services, the visual confirmation provided by the operator allows them to give the activation a priority response and increases the likelihood of the culprit of any trespass or theft committed on the property in question.

Monitored Alarm System Provides Peace Of Mind

Remote access can also assist business owners in detecting threats  such as fires, high carbon dioxide levels or intrusion that could otherwise be detrimental to their employees and valuable assets.

Business owners can use remote access with their monitored alarm system to:

·        Schedule notifications in case of an emergency.

·        Arm or disarm security systems remotely.

·        Lock or unlock doors remotely

Controlling these security features with remote access creates peace of mind for business owners who can stay connected with their business, even when they are away.

Conclusion

What makes remote video surveillance and mobile monitoring so favorable is that they both fit within your busy schedule. Remote monitoring and mobile surveillance give you on-the-go, real-time access to your live camera view so you can check up on your property anytime, day or night. The remote solutions made available by IP camera, NVR manufacturers, and even third-party mobile app developers are manifold; it is up to you to decide which one best aligns with your day-to-day routine.

Difference between Dynamic and Static IP

Difference between Dynamic and Static IP

The major difference between dynamic and static IP is that dynamic IPs change every time one connects to the internet, while static IPs remain the same.

Internet Protocols, also known as IP addresses is a 32-bit number that is usually assigned to a computer when it connected to a network, such as the Internet. The IP address works similar to an actual address and lets computers know where to send data packets. The network devices use these address in order to communicate with each other.

The IP address are made up of 4 parts of numbers that are divided by dots (.) So, a typical IP address will looking something like – 72.169.189.01.

Although, the IP Based product / computers communicate with each other using IP addresses, to make it easier to remember the internet uses DNS or Domain Name System. This DNS is sort of an address book that pairs names to IP addresses. For example, if one wanted to visit the Google website, they would type in www.google.com in the address bar. The DNS will look up the IP address (74.125.239.35) paired with this name and will ping that address. Their system will respond back and the webpage will load on your computer.

There are two types of IPs – dynamic and static IP addresses. The major difference between dynamic and static IP is that dynamic IPs change every time one connects to the internet, while static IPs remain the same.

There are limited amount of IP addresses that are available and for this reason, many companies assign dynamic IPs, unless a static IP is asked for. So, every time a device is connected to the Internet, the IP address can change. This also allows the limited number of IPs to become reused, making it more convenient.

Broadband connections today lease IP addresses and use the DCHP dynamic IP address system. This system is also often considered safer, since the IP is always changing it makes it more difficult to hack the computer. Static IPs are commonly used by companies or people who require a similar IP address. The can apply for a static IP by paying a fee.

Comparison between Dynamic and Static IP:

	Dynamic IP	Static IP
Full form	Dynamic Internet Protocol	Static Internet Protocol
Definition	The internet protocol will constantly change	The internet protocol will remain the same
Cost Effective	More cost effective	Less cost effective
Security Risk	Lower	Higher
Upload/Download Speed	Slower	Faster
Good for	Good for residential user and small business owners	Web servers, email servers and other Internet servers. Also, for VOIP, VPN, playing online games or game hosting

Common Problems and Solution for IP Cameras

IP camera or network camera is a new product which combined with analog and network video streaming technologies, in addition to its image capturing functions like the conventional analog camera, IP camera has built-in video compression processor with web server function, to compress raw video footage, then broadcast over Internet. The authorized users can access the data from anywhere with internet connection. 
What's the common problem of IP camera?

1. Can't find IP camera when you use search software

Foremost, rechecking whether power supply and Ethernet cables are connected correctly. If the problem still exists, checking the network setting for IP camera and your computer/Laptop/tester. Go to network connection, configure IP address to same IP segments, Subnet mask and default gateway must be same for both IP camera and computer. Ensuring IP camera and computer are in the same router.

2. Can't visit IP camera from Internet (WAN)

For this problem, there are two possible factors. Firstly, there is no port mapping for IP camera. As we know, IP camera requires port mapping for remotely access from Internet (WAN). Without port mapping, IP camera is only accessible from local network (e.g 192.168.1.20). To solve this problem, you just need to log in your local router, and enable port mapping for IP camera in virtual server menu. Secondly, if you use domain or DDNS service, making sure the domain point to correct IP address with correct port number.

3. Connect 4 IP cameras, but only one IP camera displays images

This problem occurs when you didn't change the default IP address of IP cameras. After you bought the IP cameras, all of them were configured with a same IP address. With reason of IP conflict, when several IP cameras connect to router, one camera can work, but the rest of cameras can't connect to network. To solve this problem, you need to set an unique IP address for each of cameras.

How to change IP address for the IP Camera ?

Accessing the camera with default IP address (e.g 192.168.1.20), then login with default account information. Go to "Device Config", then choose "Network", you can change the IP address for the camera.

4. PoE IP camera can't see at night (dark images)

Insufficient power supply, which caused the PoE IP camera can't turn on Infrared illuminators, thus images are black at night. PoE (Power over Ethernet) is useful technology which greatly reduced the cost on IP camera installation. But it also has drawbacks; the voltage will drop when PoE IP camera connects to a PoE Switch or NVR. Typically, IEEE802.3af standard PoE only can transmit 20-30 meters. To solve this, user should use high quality Ethernet cable, or shortening the connection distance.

5. Video delay (video latency) when watch live video

Since network camera need to compress the video, before broadcast over Internet, every IP cameras encounter video latency, which is a common problem in IP video surveillance system. To minimize the video latency time, you can increase the bandwidth through upgrading your network infrastructure, also you can lower the bit-rate of streaming. Lowering the image resolution also helps to reduce the video delay time. Increasing the fps can allow IP camera output smooth video.

Do you experience any of these problems? Please make comments if these information is useful to you. If you experienced other problems which are related to IP camera, please write it down in below comment section.

6. IP camera can't display images

If your IP camera can't display images, also you are not be able to access the IP camera, likely the IP camera doesn't boot correctly. Almost IP cameras work with DC12V power supply, power requirements are different. You can estimate the power requirements on the basis of IR range.

·        No IR, or IR range within 20 meters: Required Power Supply DC12V 1A

·        IR range is within 20-30 meters: Required Power supply DC12V 1A

·        IR range is within 30-50 meters: Required Power Supply DC12V 1.5A

Please note: A regular PoE switch, supports IEEE802.3af, this standard only provides maximum 15.4W power, which means the provided current is 1.25 ampere. In conclusion, the regular PoE switch only can work with IP cameras which require no more than 15.4W power.

7. How to upgrade NVR firmware

If your IP camera connects to NVR, not all problems are caused by IP camera. Sometimes, the problem was caused by NVR. You may solve the problem through upgrading or updating NVR's firmware.

To update the firmware, you need to get the firmware file in a USB stick, which then has to connect USB port of NVR for upgrading.

Step 1. Go to "System Setting", choose "System" > "Upgrade"

Step 2. Select the firmware file, then click "Upgrade".

Step 3. When upgrading succeed, the NVR will reboot.

8. NVR can find IP camera but can't display image

If IP camera can be found through automatically search on NVR, this means the IP camera works properly, NVR detected and received correct video streaming parameters from IP camera. If your NVR shows video abnormal, you need to check the video resolution setting for both IP camera and NVR. The video resolution should be same as the NVR's recording resolution. If you use our IP camera and NVR, you need to choose the system's recording resolution as in below picture:

Choosing appropriate main stream and sub-stream resolution

Dynamic DNS in Wireless CCTV Systems (For Beginners)

Wireless internet CCTV, also known as IP CCTV, communicates through your broadband line and onwards to the internet.  This can cause problems if your home broadband has a dynamic IP address, because when you want to connect to your cameras from outside, you won’t know what that address is.  This article shows you how to overcome the problem by using Dynamic DNS.

Most home ADSL packages still give you a dynamic or changing IP address, which is simply the address of your home’s network on the internet.  These addresses are allocated from a pool of available addresses and allow the internet provider to have fewer addresses than customers, saving money. 

This used to work well because early broadband modems “dialled” a connection when the attached computer requested it, rather like the old dial-up modems.  Nowadays, though, modern wireless modem/routers tend to remain connected permanently, so we are reaching the point where the internet provider is having to allow one IP address per customer, and may as well allocate a static or unchanging one.  However, as of today most people have dynamic addresses and this is an obstacle to contacting your wireless internet camera from the outside world, as I will explain in the next section.

Just as your broadband line has an IP address, so your camera has its own address or port.  For example, if your home IP address is 91.103.218.59 and the camera’s port is 8765, assuming your router is set up with port forwarding (outside the scope of this article) you can contact your camera by typing “http:// 91.103.218.59:8765” into a browser window.  This may work today, but by tomorrow that  91.103.218.59 IP address could have been allocated to someone else, and you will not find your camera on the end of it any more.  This is where Dynamic DNS or just “DDNS” comes in.

DDNS allows you to contact your wireless internet CCTV camera using an address that never changes, even when your broadband’s IP address changes.  It requires two things in order to work: a DDNS service provider and a router or camera that offers DDNS support.

Most modern wireless routers offer DDNS support, but few internet CCTV cameras do.  As long as either the camera or the router offers this feature, all is well.  First, you visit the website of the DDNS service provider and sign up for an account.  The most popular provider is dyndns.com and it’s free.  You choose your own unique internet address such as “mywirelesscamera.dyndns.org” and you will also have a user name and password.  (Incidentally, the purpose of this service is simply to make that link between your IP address, whatever it happens to be at the time, and a fixed address or domain name.)  Having registered a DDNS account, next you log into your router’s administration pages and find the DDNS section.

Here you simply key in the DDNS provider name, your account details and the address that you chose.  Now, whenever your broadband provider changes your home IP address, your router will tell dyndns.com, and this means you can always contact your camera from wherever you happen to be, by keying the same unchanging address into a browser window, in our example: “http://mywirelesscamera.dyndns.org:8765”.

Router Compatibility for Internet Enabled Wireless CCTV Systems

The modern replacement for old analogue CCTV cameras is the wireless internet CCTV, also known as IP CCTV. The wireless CCTV system that is internet enabled has a great advantage over old system. You can see your property from anywhere in the world. You can see live images and video of your business property or your house, from wherever you are, just with the help of internet.

The technology has come in the market, but not many people know how to best use to. In order to get the best out of your wireless internet CCTV system, we must also look at the requirements and features that a router would need in order to be used successfully with the wireless system. There are a lot of things that goes into deciding your router for the wireless internet CCTV.

Broadband Type and Router Compatibility

You can have a broadband service that can come through either a phone line or a satellite CCTV box. In case the broadband service is through a phone line, you will require an ADSL modem/router also known as the DSL modem/router. Alternatively, if your broadband comes from your cable supplier, you would then require a cable router. This is another box that plugs in to your cable box.

The router part of your DSL modem/router or the cable router is basically the same. Manufacturers just make the DSL or cable version of the router that has the same features.

Router Features for Wireless CCTV System

• The router must be set up so that the port number, a special code, is allocated to the camera. When you type the IP address and the port number in the internet browser from any system, the router sees the port number and passes the message to the camera. Without this facility, it will not be possible to view your property through internet.
• With broadband suppliers changing your IP address at will, DDNS i.e. dynamic DNS support comes in. It helps you to use a third-party service to link a domain name you your IP address. The router’s DDNS feature makes sure that the router will tell the DDNS provider about your current IP address. Thus, even if your IP address changes, you can contact your camera with the domain name of the DDNS.
• Having your router remain connected is very important. This is important especially when you go out on a vacation. You don’t want to find that you cannot connect to your camera because your router disconnected due to power failure. In case of power cut, the DSL line or cable may drop for some time. Not many home routers are able to handle this, but with technology, new routers are able to reconnect by themselves after power cut. The router is able to sort itself out once the power is back and provides you hassle free access to your camera from anywhere in the world.

Thus, a router is an important device that enables you to monitor the security of your home and business’s wireless cctv systems from anywhere in the world.

Choosing Routers for Wireless Internet CCTV

Wireless Internet CCTV, also known as IP CCTV, is the modern replacement for old analogue CCTV cameras, and has the great advantage that you can see your property, live, from wherever you happen to be, using the internet. Now that the technology has become popular in homes and businesses, people need to know how to get the best out of it. In this article, I want to look at the minimum set of features that a router needs in order to be used successfully with wireless CCTV.

First, a quick note about types of broadband and router compatibility. Your broadband service is likely to come through your phone line or perhaps via a satellite CCTV box. If it’s through a phone line, you will need an ADSL modem/router, sometimes called a DSL modem/router. The modem part of the box is what talks to the phone line. On the other hand, if you have broadband from your cable supplier, you need a cable router. This is not the cable box itself, but another box that plugs into your cable box. The router part of a cable router or a DSL modem/router is usually the same, with many manufacturers making cable and DSL versions of what is essentially a router with the same features. Now, let’s take a look at the features you will need to get the most out of your wireless internet CCTV system:

• Virtual Server/Port Forwarding. This just means having the ability to set up the router so that a special code known as a port number is allocated to the camera. When you open an internet browser window and type in the URL or address of the camera, you add this special port number onto the end of the camera’s address, (e.g. for port 8765, you would type “http://:8765″) and when the router sees the port number it knows the message is to be passed to the camera. Without this facility, you would not be able to see your property over the internet.
• DDNS Support. It stands for Dynamic DNS and is used where the address of your home or business on the broadband system, known as the IP address, is changed at will by the broadband supplier. Most DSL broadband services have changing IP addresses, also known as dynamic IP addresses. Say you have an IP address of 91.103.218.59 (they tend to look like this) today, with dynamic IP addressing it could be something different tomorrow. This means you would never know what address to use to access your camera over the internet, and that is where DDNS support comes in. Basically, you use a third party service to link a domain name to an IP address. This service is provided by a separate DDNS provider and can be free, e.g. dyndns.com. The router’s DDNS feature means that the router makes sure it always tells the DDNS provider what your current broadband IP address is. Therefore, even if the IP address changes, you can always contact your camera by using the same dyndns address, e.g. “http://myipcamera.dyndns.com:8765″.
• Keep alive or auto-reconnect feature. This feature is all about making sure the router stays connected. You may have a power cut, or the DSL line/ cable connection may drop for a few moments. In these scenarios, you want the router to sort itself out. Earlier models of home router did not handle this well, and even today some can still be bought that don’t reconnect after a power cut or especially a broadband fault. The last thing you want is to go on holiday and then find you cannot log into your camera because a power cut several days ago left the router disconnected, so this is important.
• Encryption. Most routers these days offer some sort of encryption, usually known as WEP or WPA. WPA is stronger and preferable. Encryption is simply encoding the messages on your wireless network so that they cannot be intercepted easily. Make sure you get a router that offers at least one type of encryption that your wireless internet CCTV cameras offer. For example, it is no good getting a router which only does WPA encryption if your cameras can only do WEP.

As always, if what you have read here leaves you dizzy and you just want an internet CCTV system to monitor your home or business without all this technical complication, my advice is to get a fully-configured wireless CCTV camera pack from a specialist supplier.

How To Convince Your Customers To Choose IP Cameras Over Analog

As IP surveillance technology becomes more affordable, it’s also becoming a more attractive solution for smaller installations – installations that used to be the sole domain of analog product. But how do you convince your customers to upgrade their analog to IP, preferably before an incident forces their hand? There are three primary selling points for an IP system of an Analog system – higher resolution, more in-depth analytics, and the ease of new network configuration.

Modern IP cameras generally offer a higher level of resolution than analog cameras. Almost all analog cameras will be limited to the equivalence of a 4CIF or D1 resolution (that is, 704 x 480 or 720 x 480). Many IP cameras boast 5MP resolutions or higher – that’s 15.5 times more pixels than a standard analog camera! And a higher pixel count means more usable surveillance information. This is especially important when it comes to identifying intruders. For positive identification, a general guideline is to have at least 12.7 pixels per inch across the face of a suspect. It’s much better to have that resolution in place during an incident, rather than upgrading to that resolution because the suspect could not be identified with footage from the existing system.

For positive identification, a general guideline is to have at least 12.7 pixels per inch across the face of a suspect.

Another way to utilize this higher resolution as a selling point is the potential lower cost of the total installation. A camera with 5MP mounted 10 feet away from the viewing area will be able to provide identification level resolution across 17 feet horizontally, while a standard analog camera can only cover just over a quarter of this area. This means that you would need four analog cameras to provide the same level of coverage as one 5MP IP camera. When cables, software licenses, mounting hardware, lenses, and all other costs are factored in this can make the IP installation much more appealing from a cost basis.

Another advantage that IP cameras have is the ability to perform increasingly sophisticated analytics onboard the camera itself. Most recorded video is never watched – typically, footage is only reviewed when there is an incident. This is especially true on small installations that do not have a dedicated security guard. With the advent of on-board analytics, IP cameras themselves can now be programmed to independently analyze events, interact with other alarm systems, and send email or text alerts with pictures to interested parties. For example, a camera can be programmed to watch a specific door and only send an alert if that door is opened after regular business hours. At the very least, analytics can make it easier to sift through footage after the fact.

Finally, a lot of customers are concerned that IP video is overly complicated to manage when compared to an analog system. It’s true, earlier versions of IP cameras did require some level of networking know-how. But newer cameras are getting extremely close to plug-and-play with features that automatically detect and configure cameras added to a network through tools such as DDNS, DHCP, and other networking protocols. Depending on the brand selected, all that could be involved in the installation of a new device is plugging the camera into the switch and then selecting “Detect New Hardware” in the accompanying software. Network cameras can also run on existing network infrastructure and only one cable is required for both data and power with Power over Ethernet technology.

As every device begins to merge onto the network, it makes sense that security cameras move there as well. An IP video installation may cost more than a conventional analog system, but the price difference is getting smaller – and the benefits are increasing.

How Domain Name System (DNS) Works

In the world of Internet and the area of computer networks, you will often come across the term Domain Name System or Domain Name Service which is simply referred to as DNS. The working of DNS forms one of the basic concepts of computer networks whose understanding is very much essential especially if you are planning to get into the field of ethical hacking or network security.

In this post, I will try to explain how Domain Name System works in a very simple and easy to follow manner so that even the readers who do not have any prior knowledge of computer networks should be able to understand the concept.

What is a Domain Name System?

A “Domain Name System” or “Domain Name Service” is a computer network protocol whose job is to map a user friendly domain name such as “arindamcctvaccesscontrol.blogspot.com” to its corresponding IP address like “173.245.61.120″.

Every computer on the Internet, be it a web server, home computer or any other network device has a unique IP address allotted to it. This IP address is used to establish connections between the server and the client in order to initiate the transfer of data. Whether you are trying to access a website or sending an email, the DNS plays a very important role here.

For example, when you type “www.google.com” on your browser’s address bar, your computer will make use of the DNS server to fetch the IP address of Google’s server that is “74.125.236.37″. After obtaining the IP address, your computer will then establish a connection with the server only after which you see the Google’s home page loading on your browser. The whole process is called DNS Resolution.

With millions of websites on the Internet, it is impossible for people to remember the IP address of every website in order to access it. Therefore, the concept of domain name was introduced so that every website can be identified by its unique name which makes it easy for people to remember. However, the IP address is still used as the base for internal communication by network devices. This is where the DNS comes in to action that works by resolving the user friendly domain name to its corresponding machine friendly IP address.

In simple words, domain names are for humans while IP addresses are for network devices. The “Domain Name System” is a protocol to establish a link between the two. Hence, it is not a surprise that you can even load a website by directly typing its IP address instead of the domain name in the browser’s address bar (give it a try)!

Types of DNS Servers and their Role:

The Domain Name System (DNS) is a distributed database that resides on multiple computers on the Internet in a hierarchical manner. They include the following types:

Root Name Servers:

The root servers represent the top level of the DNS hierarchy. These are the DNS servers that contain the complete database of domain names and their corresponding IP addresses. Currently, there are 13 root servers distributed globally which are named using the letters A,B,C and so on up to M.

Local Name Servers:

Local servers represent the most lower level DNS servers that are owned and maintained by many business organizations and Internet Service providers (ISPs). These local servers are able to resolve frequently used domain names into their corresponding IP addresses by caching the recent information. This cache is updated and refreshed on a regular basis.

How DNS Server Works?

Whenever you type a URL such as “http://www.google.com” on your browser’s address bar, your computer will send a request to the local name server to resolve the domain name into its corresponding IP address. This request is often referred to as a DNS query. The local name server will receive the query to find out whether it contains the matching name and IP address in its database. If found, the corresponding IP address (response) is returned. If not, the query is automatically passed on to another server that is in the next higher level of DNS hierarchy. This process continues until the query reaches the server that contains the matching name and IP address. The IP address (response) then flows back the chain in the reverse order to your computer.

In rare cases where none of the lower level DNS servers contain the record for a given domain name, the DNS query eventually reaches one of the root name server to obtain the response.

FAQs about Domain Name System:

Here is a list of some of the FAQs about DNS:

How does a “root name server” obtain the information about new domains?

Whenever a new domain name is created or an existing one is updated, it is the responsibility of the domain registrar to publish the details and register it with the root name server. Only after this, the information can move down the DNS hierarchy and get updated on the lower level DNS servers.

What is DNS propagation?

Whenever a new domain name is registered or an existing one is updated, the information about the domain must get updated on all the major DNS servers so that the domain can be reached from all parts of the globe. This is called DNS propagation and the whole process can take anywhere from 24 to 72 hours to get completed.

How often the DNS servers are updated to refresh the cache?

There is no specific rule that defines the rate at which DNS servers should be updated. It usually depends on the organization such as the ISP that maintains the server. Most DNS servers are updated on an hourly basis while some may update their databases on a daily basis.

I hope you have now understood the working of DNS in a very convincing manner. Pass your comments and share your opinion.