The advent of HD CCTV systems has effectively killed off the standard analogue (D1) systems which have been ubiquitous over the past five decades. As explained in the article ‘HD-TVI CCTV Explained’, there are really only two contenders in the race for high definition CCTV – HD-TVI and HD-IP. The emergent HD-AHD may yet play a significant role, but it will need to be adopted by a mainstream CCTV manufacturer if it is to make a dent in the market. Both HD-TVI and HD-IP have been adopted by leading CCTV manufacturers and as such look to dominate the market for a considerable time.
In regard to the resolutions available HD-IP systems win hands down. The maximum resolution achievable in HD-TVI is 1080P which is equivalent to 2.073 megapixels; which in itself is no mean feat at 4x the resolution of D1 systems. HD-IP easily surpasses this with up to 5 megapixel recording being readily achievable, albeit at a cost.
If you are installing a CCTV system from scratch then you should really consider an HD-IP system, although if cost is a big consideration then HD-TVI is a viable alternative. HD-TVI could be a serious alternative if you are looking to upgrade an existing D1 analogue system. HD-TVI can use any existing analogue cameras and can use the existing analogue cabling. In such a system the analogue cameras will record at their rated resolution – up to 700 TVL (TeleVision Lines) and installed TVI cameras will record at their rated resolution (720P or 1080p).
One great advantage of IP CCTV systems is the ability to use PoE (Power over Ethernet). Basically this facilitates powering of the cameras through the same Ethernet cable as the data. I.e. a single CAT5 cable is the only connection to the camera. The use of PoE is explained in the article ‘Using PoE in IP CCTV’.
IP-CCTV is a fully digital method of capturing, transmitting, and recording video data. IP stands for Internet Protocol, but IP-CCTV has nothing to do with the Internet, well at least until cameras and NVRs are connected to the internet. That said, it does use the same protocols as TCP/IP connectivity. As such, each device on the IP system has to have a unique IP address in the form xxx.xxx.xxx.xxx. Within the system the IP addresses are regarded as local addresses. It is not necessary to fully understand IP addressing but it does help to have a basic knowledge.
A typical small IP-CCTV system may comprise an NVR (Network Video Recorder) and say 4 IP cameras connected by CAT5/6 Ethernet cable. The system can be considered as an Intranet and each device will have an IP address such as 192.168.1.100 for the NVR and 192.168.1.101, 192.168.1.102, 192.168.1.103, 192.168.1.104 for cameras 1 to 4. Note that the first three sets of numbers of the IP address are identical. The NVR will see the 4 cameras as four different channels and the NVR hardware/software can record/playback and manipulate the images received. This system will work fine as a self contained CCTV system, however, in today’s connected world, we really want to be able to see and control the system from anywhere in the world and to do so we need to connect the system to the internet.
Connecting IP CCTV Systems to a Local area Network (LAN)
Assuming that we eventually intend to connect the IP CCTV system to the internet through a router, we first need to connect the NVR to the router.
If you remember earlier about IP addresses, the same applies – the router and the NVR need to be on the same subnet i.e. the first three sets of numbers need to be the same. As an example, our router address is 192.168.1.1, and say we have two PCs connected to the router and they are addressed as 192.168.1.2 and 192.168.1.3. In the previous example our NVR’s IP address was 192.168.1.100 and as such is on the same subnet and will be part of our Intranet.
It should be noted that high-end NVRs such as those we supply manufactured by Hikvision are ‘self-adaptive’ and the NVR will automatically assign its IP address to be on the same subnet as the router. It will also automatically assign the IP addresses of the IP cameras.
If you type the routers IP address into a browser on a PC connected to the local area network (i.e. the same router as the NVR) then you will be able to access the NVR – the NVR has the built-in software required to display itself on the browser.
Connecting IP CCTV systems to a Wide Area Network (WAN)
Now that you have the IP CCTV system viewable locally you are only a couple of steps away from accessing it via the internet. In order to achieve this you have to allow the internet to access the NVR. With Hikvision NVRs there are two ways to achieve this - using the EzViz system from Hikvision or the traditional port forwarding method.
Every NVR supplied by Hikvision has a unique QR code and registration number. Connecting to the internet is simply a matter of connecting the NVR to a router, installing the Android or I-os App and then simply scanning the code.
Traditional Port Forwarding
To accomplish this you will have to port forward the required ports on the router.
If you log into the NVR and look under the network settings you will see which ports the NVR is setting for access. You will normally see ports for HTTP (typically 80, 81), media or mobile (all sorts of numbers like 8000, 9000, 34567 etc.). You will need to log into your router and set up port forwarding for the ports you are using. You will then be able to access your IP CCTV system by typing your external IP address followed by a colon and the port number that you forwarded into a browser, for example if your external IP address is 126.96.36.199 and you forwarded port 81, then entering 188.8.131.52:81 will access your IP CCTV system.
The router is the bridge between your local LAN and the internet. Your router connects to the internet via an external IP address. If you type ‘what’s my ip’ into Google it will show you your external IP address. Unfortunately with most internet service providers (ISPs) this is a dynamic address and will change on a regular basis. In order to allow you to access your system over the internet this address needs to be static – otherwise you will have to re-configure your remote viewing software to point to your new external IP address. This can be solved by using a static IP address or by using a DDNS service like No-IP which will automatically point to the correct nameservers and behave like a static IP address.