(Understanding the Basic Elements of this Backbone) – Part I
The electronic security industry has moved into the IT space, with IP technologies growing in significance and application. Most CCTV, access control, intruder detection and intercom systems now offer IP network interfaces, allowing devices or control panels to communicate over an IP infrastructure.
This trend towards IP based security systems is firmly established. The trend is away from analog-based video systems that run over coaxial-cabling systems and toward IP-based systems running over twisted-pair and/or fibre-optic cabling systems. This transition from Analog to IP based security systems is also true for other end points like Sensors and Intelligent Building Management Systems.
By utilising an IP network, these technologies can work together using the same communications protocol and perform as a complete solution. This enables the security requirements of the network to be considered as a whole.
The massive amount of data that is collected, transformed, and delivered across the network requires a state-of-art network. Not only does the system need to support current data requirement, but it must also accommodate the future volumes of data as the organization grows.
The role of the network is very important, as it is critical to the performance of overall Security System.
Basic Elements of the Network
Passive Components
Wall outlets – to which the end points (cameras, readers etc) are connected
Patch panels and Cabinets
Horizontal: Cat 6 / 6a/ 7 UTP cable – medium between the end point and the main cross connect
Vertical (backbone): Fibre optic cable; WiFi – not quite passive
Active Components
Hub aka repeater: This broadcasts the same data to all its ports. Hubs do not manage any traffic coming through them; they only broadcast or repeat packets from an incoming port to all other ports.
Switch: This is more sophisticated than a hub. It forwards data only to those devices that the data is intended for, as it uses MAC addresses to forward data to the correct destination. A switch is considered a Layer 2 device operating at the data link layer. Switches use packet switching to receive, process and forward data.
Router: A router is a more sophisticated device than a switch. It connects computer networks, for example, connecting a campus network with the Internet. They connect LAN’s with WAN’s. Routers transfer packets of data between networks to establish and sustain communication between two nodes in an internetwork. Routers operate at Layer 3 (network layer) of the OSI model; a router uses the destination IP address in a data packet to determine where to forward the packet. In addition, routers often perform (a) network address translation (NAT), which allows all devices on a sub-network (e.g., all devices in a campus) to share the same public IP address and (b) sometimes include built-in firewalls to improve the network’s security.
Although the two names are mistakenly interchanged, switches and routers are not the same!
Network Topologies
Bus Topology
This topology is typically deployed where a backbone of optical fiber cable runs around the perimeter of a premise so as to connect all the devices/cameras to the network. This is the simplest way to design the network of a Security System.
Ring Topology
This is an arrangement of cameras/ security devices in a ring – creating a closed logical loop in the network. Every device receives the signal first and then transmits it further to the other device.
Star Topology
This topology is generally used when the premise is small and all the security devices are networked to a central hub or a core switch. In this case network failure for one device does not affect the other devices.
Mesh Topology
Mesh Topology is generally used in ‘wireless city surveillance applications’. In this topology, all the security devices are connected to each other, giving a lot of redundancy to the network.
Summary
The electronic security industry has moved into the IT space, with IP technologies growing in significance and application.
By utilising an IP network, all the security systems can work together and perform as an integrated solution. This enables the security requirements of the network to be considered as a whole.
The role of the network is very important, as it is critical to the performance of overall Security System.
Security Teams need to quickly understand the basics of Networking. This is important and necessary.
Security and IT teams can no longer work in isolation.
(Part II will follow shortly……..)
Kiron Kunte, Director, Norik Konsult,
About Author
Kiron Kunte has over 35 years of design and solutions experience, in Security, Telephony and Networking infrastructure. He is a graduate of IIT Bombay, a Fellow of the Institute of Engineers and has a post-graduate diploma, from Bombay University, in Systems Management. He is professionally certified in the design and engineering of Data Centres, IP Telephony, Video surveillance and Structured Cabling solutions. He heads Norik Konsult, a practice that offers advisory, design and system planning help to upgrade or build a new Telephony, Security and Networking infrastructure.
