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Networking 101

Posted on January 3, 2014 in Network IP Security

IP Network Basics

IP video cameras, network video recorders (NVRs) and turn-key IP security solutions all connect to a network. Take a look at our basics of a network below, so you have a better understanding of IP security solutions.

What’s a Network?

A network is simply two or more devices connected together that share hardware and software. The devices also usually share the same topology and protocols. A network may consist of IP cameras that are cabled into a switch, a Network Video Recorder (NVR), a client workstation and a router. There are two main types of networks: local area networks and wide area networks.

Local Area Networks

A local area network (LAN) provides computer workstations, servers, smartphones and other devices within close proximity of each other with networking capabilities. A LAN is useful for sharing resources such as files and printers, in small geographical areas such as offices, schools and home environments. A LAN can be set up with various topologies including: bus, star and ring.

Star topology is the most widely-used computer network topology set up on a LAN. A star network consists of one central hub or switch, which acts as a channel or central node to transmit messages between computer workstations and peripherals. Star topology reduces the chance of network failure because all systems are connected to a central node, and if a computer or device drops off, you will not lose your network.

Wide Area Networks

A wide area network (WAN) allows you to connect workstations and devices in larger geographical locations, such as two remote locations around the world, via a privately-owned or leased line (from an ISP provider). For example, if you had a business in Los Angeles set up on its own LAN and another business in China set up on its own LAN, you could create a WAN with direct, continuous connectivity between both buildings in the remote locations (Los Angeles and China). A WAN acts like an interface between LANs to facilitate long-distance communication. A WAN is designed to grow with changing needs, and to cover locations in multiple cities, countries and continents. The Internet is a public WAN.

Network Communication Benefits

There are many benefits of network communication regarding IP cameras. First of all, IP network cameras connect to your existing network and are capable of using power over Ethernet (PoE). PoE allows IP (internet protocol) devices to receive power and data over existing LAN (local area network) cabling; eliminating the need to install a separate power cable and simplifying installation. With PoE you can pull one cable and connect to the nearest Ethernet port and you are ready to go. IP cameras also allow you to view and manage features remotely via your network and over the internet.

Understanding IP Network Cabling

Your choice of cabling is one of the most important decisions you’ll make when installing the right type of cable for your IP network. Network cabling is the backbone of your network, and your cabling is extremely important for your application; IP security applications require a robust backbone.

What is Network Cabling?

Network cabling is the connecting cabling between the floors or areas of a building. If you have a 3-story building, between each floor is the cabling that connects to your routers.

Twisted Pair Cables

Twisted pair cables consist of two insulated copper wires and is a form of wiring in which two conductors are twisted together. Twisted pair cables can be shielded, unshielded or foiled, and the twisting of the cabling is designed to cancel out electromagnetic interference from external sources and other devices.

Fiber Optic Cables

Fiber optic cables have a glass core center, consisting of several threads of glass surrounded by layers of protective material with an outer insulated jacket. Fiber optic cables do not transmit electronic signals; they transfer light which eliminates the problem of electrical interference. Fiber optic cables can transmit data over longer distances, but can be difficult to install. Fiber optic cables have greater bandwidth than metal cables and can carry more data.

Coaxial Cables

Coaxial cables (Coax) transmit an electrical impulse signal along the length of the cable, between the center and outer conductor which share the same center line (axis). The outer conductor acts as a shield, defending against interfering signals. Coax cabling also keep the signals from escaping and interfering with nearby devices. In order for a megapixel IP camera to work over existing coax cabling, you need to use an adapter.

Network Cable Categories

There are a few main types of cable categories: category 3, category 5, category 5e, and category 6 cable. They’re all very similar and represent data transmission, but the speeds, length and cable type vary between them. For example, in a twisted pair cable, the tighter the twist, the faster the cables can talk to each other.

CAT-3 Cables

Category 3 (CAT-3) cabling is an unshielded twisted pair of UTP cables. CAT-3 cables are not twisted together very tightly (compared to a CAT-5 cable). A 10 megabit or a 10 T cable, which is CAT-3, has bandwidth to handle 10 megabits of data per second and can run for 100 meters.

CAT-5 Cables

Category 5 (CAT-5) cabling is an unshielded twisted pair of cables that contain 4 pairs of copper wires. CAT-5 cables are twisted together more tightly than CAT-3 cables and can move data at faster speeds. CAT-5 cables rely on the tightly twisted design and differential signaling to cancel out noise. 100 T cable, which is CAT-5, has bandwidth to handle 100 megabits of data per second and is still limited to 100 meters of distance it can run.

CAT-5e Cables

Category-5e (CAT-5e) cabling stands for Category-5, enhanced). CAT-5e cables are unshielded, twisted pair, copper gigabit cables which can support networking at Gigabit Ethernet speeds. Gigabit cables have the bandwidth to handle 1,000 megabits (1 gigabit) of data per second and can run up to 100 meters in distance. CAT-5e cables can run 1,000 megabits (1 gigabit) of data up to 100 meters at a cable frequency rate of 100 MHz.

CAT-6 Cables

Category-6 (CAT-6) cables are also unshielded, twisted pair, copper gigabit cables which can support networking at Gigabit Ethernet speeds, but CAT-6 cables have thicker copper wiring and can transfer data and more reliably than CAT-5e. CAT-6 cables can transfer 1,000 megabits (1 gigabit) of data up to 100 meters at a cable frequency rate of 250 MHz.

Cable Standards for IP Cameras

Regardless of the difference of each type of cable, you should note that each type of network cable runs up to 100 meters. Cable standards for IP cameras are 100 meters. This is important because when you are running IP cameras, the maximum distance you can run it before you have to use an extender or power injector is 328 feet, or 100 meters. This is different from running analog cameras, which allow you to run from 100 feet, and if you add an injector, you can run 1,000 feet.

Networking Bandwidth

Networking bandwidth is also important for security application. Bandwidth is defined as either channel capacity or maximum throughput on your network.

To give you an analogy of bandwidth, imagine going to work from your house, and between your house and your work, you go down a main interstate or thoroughfare. Generally, early mornings and when school is in session, there’s a lot of traffic, which is similar to having low bandwidth. You would not be able to go the maximum speed that you would want to go, because of all the increased traffic and other cars around you.

The same thing applies to cabling. If you had CAT-3 cable and you only had 10 megabits of bandwidth, but yet you wanted to send 16 megabits worth of data. It takes longer to get that transmitted.

On the flipside, imagine going to work on a Saturday to pick up your laptop or your wallet that you left at your desk. You leave early Saturday or Sunday morning, there’s no traffic, you’re able to go the maximum speed that you want to go and get there twice as fast, because there is less traffic, or more bandwidth. Well that’s essentially what happens when you use CAT-5e or CAT-6 gigabit cable or fiber. You open up the bandwidth, which allows you to move and transfer data much faster.

Network Cable Standards

IEEE – the Institute of Electrical and Electronic Engineers – was established in 1980. This institute developed the set of LAN and WAN standards and technologies called the 802 project. The 802 specifications define the operation of the physical network components—cabling, network adapters, and connectivity devices such as hubs and switches. The 802 project has a number of subsections ranging from 802.1, the beginning of internet working standards, to 802.3 developed for IBM and 802.11 which is for wireless networking technologies and standards.

Within 802.11, there are 3 commonly used wireless standards or networks: 802.11b, g, and n. B came out in the 1990s. It was 11 megabits on the 2.4 GHz frequency. Shortly after, g came out, which allowed you to move up to 54 megabits on the same 2.4 GHz frequencies. Most recently, n came out. What’s nice about n is it runs on the 5.8 GHz, so there’s not nearly as much interference, and you have a 300 megabit bandwidth.

Patch Cables and Crossover Cables

Along with networking cable standards, you need to consider whether you will use patch cables or crossover cables.

Patch Cables

A patch cable is just a shorter cable version of what you’re going to run in your network when you’re connecting cameras to the switch. Patch cables, if you want to test a camera, require you to plug the patch cable from your laptop into a switch and then get another patch cable and plug it into the device you want to test. It’s important to know how they are set up. The ends are plugged in; wired in just as if you’re doing big runs.

Crossover Cables

Crossover cables allow you to test equipment on the fly. Basically the pins are reversed on each end from each other, and it allows you to plug from a laptop directly into an IP device and get connectivity.

The crossover cable helps you quickly identify what’s going on. It allows you to log directly into your IP device, and doesn’t require you to have a switch or anything like that for testing purposes and will make for a quicker installation.

Your IP security applications depend on the strength of your network. Choose the appropriate type of cabling that will provide a robust backbone for your network that will deliver the data transfer speeds

Your Choice of Cabling is Important for Your Security Applications

Your IP security applications depend on the strength of your network. Choose the cabling that will provide a robust network with the appropriate length and data transfer speeds for your security applications.

Networking Hardware

Your selection of networking hardware, including hubs, switches and routers is also important when installing an IP security solution. These devices are all used to connect computers together on a network, but each device has different capabilities.


A hub is a device with multiple ports which has several cameras or computers connected to it. People often get hubs and switches confused. Hubs are the original switch, so to speak. There are some limitations with hubs. They have no real built-in intelligence for moving data between two devices more efficiently. Hubs also share total network bandwidth, so if you have a 100 megabit hub, and you have 8 items plugged into that hub, they have a maximum bandwidth of 100 megabits that they can share between them.


Switches generally have some intelligence built into them. We call them smart switches. It really increases efficiency of data transmissions. What’s nice about a switch, and what separates it from a hub is you have a maximum bandwidth per channel, so if you have a gigabit switch, you have a gigabit per channel that you can push data through. This makes a switch a lot better than a hub.

Hubs and switches are fairly similar in price, but since switches allow for greater bandwidth per channel and more efficient data transmission, a smart switch can be a better choice than a hub.


A router is a much more intelligent device than a network hub or switch. Network routers serve as an intermediate destination for network traffic to ‘route’ data. The devices are designed to join multiple LANs and allow you to speak to different networks within a building, or even around the world.

If you have a LAN set up in your house, every device on your LAN can communicate with each other. A router provides your LAN or computer on your LAN with the ability to communicate with the Internet (WAN), and transmit data to a computer in another state, country or other distant location. Routers can be wired (using Ethernet cables) or wireless.

Internet Protocols

When it comes to IP security, there are two basic protocols used in the world today, TCP/IP and UDP. Most, if not all, IP cameras use UDP protocols.

User Datagram Protocol (UDP)

UDP is a transport layer protocol for client/server network applications based on Internet Protocol (IP). UDP is commonly used for quickly sending and streaming audio and video. UDP allows you to transmit data packets and provides speed. UDP does not check to make that the other devices the data packet was transmitted to have received the data. This protocol spools out data really fast without verification and then moves on to the next task. In the case of an IP camera, this protocol will spool data, and keep feeding it in live fashion, but there is no guarantee or confirmation of delivery.

Transmission Control Protocol (TCP) or TCP/IP

TCP was developed in the US in the 1970s for ARPNET. It is commonly referred to as TCP/IP and is the most commonly used protocol on the Internet. TCP/IP was set up to make data transfer more scalable and reliable. This protocol sends out large amounts of data, and then every so often it sends out a message confirming delivery of sent data packets.

When TCP/IP sends a data packet, it waits for a response from the computer it’s sending the information to, and if the receiving computer confirms that it has received the previous packets of data the protocol will continue sending the data until it’s done with the entire task of transferring all of the data packets. If the computer on the receiving end sends back a message confirming that data packet 3 of 100 is missing, the protocol will resend data packet 3. TCP/IP also keeps your files and programs in order, complete and whole.

TCP is a lot like sending a registered letter via the post office. The letter (data) gets delivered and you receive a signed piece of paper (confirmation) that your letter has made it to the recipient. UDP on the other hand, is like sending out a large amount of cards out via regular mail during the holidays, the cards (data) may or may not get to the recipient, but you want to get the cards out as quickly as possible.

IP Addresses

IP addresses are required for TCP/IP communication. IP addresses are a 32-bit numeric address written as four numbers separated by periods. The numbers are always between 0 and 255. IP addresses can be static or dynamic. Each computer must have an IP address in order to connect to the internet, and each IP data packet must have an address before it can be sent to another computer.

IP addresses must be unique on each network on a LAN or WAN. You do not want to choose your IP addresses randomly; you will want to follow a method. For example, if is your base IP address on your LAN, then you will want to go up in a sequential order as you add devices.

Media Access Control Address (MAC)

A MAC address is just as important as an IP address. A MAC address refers to the physical address that is set up on the network interface card (NIC) or on each device. A MAC address is a unique number, similar to a social security number – a unique MAC address is assigned to every device, which allows you to quickly and easily locate devices on your network.

Other Parameters of TCP/IP Communication

Other parameters around TCP/IP are sub-net mask, default gateway, and DNS servers. Setting these up for a camera is going to be similar to setting them up on a computer. On a computer, if you were to hit your start button, go into the control panel, and then click “Networking”, about the 4th or 5th option down on your Windows Networking Connection Properties is something called Internet Protocol version 4, TCP/IP V4.

Click the properties on that and to the right of it a box will appear. You can see how you have your IP address, your sub-net mask, and your default gateway. That’s where you set everything up, and each computer and each camera needs to be independent and unique from each other.

Subnet Masks

A subnet mask is a 32-bit number that masks an IP address and allows the IP address to be subdivided into two parts (extended network address and a host address) for enhanced security. A subnet mask allows you to know how many routers you need to talk between networks.

There are 3 address classes for subnet masks: Class A, Class B and Class C.

Class C

Class C is the most widely used subnet mask. A Class C subnet allows you to have 255 possible combinations of IP addresses for the computers set up on your network to talk to each other, before you need a router. You can put 255 cameras or 255 devices on you network.

Class B

Class B allows you to scale up into a larger infrastructure system. It allows you to put 65,000 different IP addresses on one network to talk between each other, before you need a router.

Class A

Class A goes even further with the ability to put 17 million possible combinations of IP addresses before you need a router.

Dynamic Host Configuration Protocol (DHCP)

DHCP is a network protocol used to configure network devices, so they can communicate on an IP network. DHCP provides automatic assignment and central management of IP addresses. With DHCP, there’s no guesswork involved in choosing an IP address for each device, it’s done automatically, and a new IP address is automatically assigned if a device is moved and plugged into another place on the network.

Without DHCP, an IP address must be entered manually for each device, and a new IP address must be assigned when a computer or other device moves to a new location on the network. DHCP gets its own IP address for a device, and then the device is automatically on the LAN and you are communicating with it.

Ping Characteristics

Ping characteristics are also important in relation to TCP/IP. To ‘ping’ something is to test the connectivity between two devices on your LAN. Connectivity is important to know. If you go to the start menu on your computer, and go into the command prompt and type ‘ping’ plus your IP address, you can see if the device is live and working.

If you were to type in ping, space, and then an IP address, like, you would see the following information; 0 data packets lost, which would indicate that you have connectivity between 2 devices. If you get a ‘timed out’ message several times in a row, listed one after the other, it means that the device is either not plugged in, it doesn’t have the right IP address, subnet, or gateway, or the pin out in your cable could be wrong. A cable tester is a great tool to ensure that the pin out is correct and you are getting connectivity down the cable.

Domain Name System (DNS) Characteristics

DNS defines things in a hierarchical name space for computer networks, resources and services connected to the Internet. DNS assigns a ‘domain name’ to an IP address, to make navigation on the Internet much easier. The numbers of an IP address are hard to remember, with DNS characteristics, you can attach a name versus a number to an IP address.

IP Addresses Simplified

When it comes to IP, Your internet service provider (ISP) can either assign a static or dynamic IP address for Internet Protocol networks.

Static IP Addresses

Static IP addresses are constant—they never change. Having a static IP address is convenient, because you will always know what your IP address is every time you connect to the internet, and do not have to worry about it changing like a dynamic IP address. Most ISPs charge a monthly fee for you to have a static IP address and prices vary by ISP.

Dynamic IP Addresses

Dynamic IP addresses change—they are dynamic and never stay the same. Dynamic IP addresses change based off of the internet service provider (ISP) and their protocols. You could have a dynamic IP address that changes every 5 minutes, or it could change every 5 days, monthly, or some other change frequency, as the ISP deems necessary. Because dynamic IP addresses change, finding out what the IP address changed to can be difficult, unless you enlist a dynamic DNS service.

Dynamic DNS Services

Dynamic DNS Services can provide a DNS server that allows you to set a name IP address that keeps up with the numeric dynamic IP address as it changes. The assigned name value with always stay the same, which simplifies dynamic IP address management.

Here’s an example of how it works. Imagine you have set up on a DNS server provided by a Dynamic DSN Service provider for your dynamic IP address. Every time you type in, the server will check the numeric IP address to see if it has changed, and then automatically updates it.

The update happens behind the scenes, and you never have to worry about having to find out what your numeric dynamic IP address has changed to, because the DNS server automatically directs you to despite the numeric IP address change.