In the world of IT, a ‘switch’ can refer to two completely different pieces of technology; it can mean either a network switch or a telecoms switch. This article talks about the key characteristics and differences between these two types of switches.
What is a Network Switch?
In networking, a switch is a piece of hardware that allows devices on a computer network to communicate with each other using a technique known as ‘packet switching’. The switch receives, processes, and then forwards incoming data packets to the appropriate destination at Layer 2 (Data Link Layer) of the 7-layer OSI model. Some switches also process data at Layer 3 (Network Layer). These are known as multi-layer switches.
Network switches include multiple data ports. A 24-port switch, for example, can connect to 24 different network devices via data cables plugged into each port. Unlike repeater hubs, switches only forward data to specific devices, rather than broadcasting data to every port. Each connected device is identified by its network address, which enables the switch to control the flow of traffic between appropriate devices, improving the efficiency and security of the network.
Switches play a key role in modern networks, and they come in many shapes and sizes including rack-mounted switches, standalone switches, and desktop units for home office use. Ethernet switches are the most common type, although switches also exist for other networks like ATM and Fibre Channel.
Telephone Exchange Switches
In telephony, a switch is a telephone exchange that connects two or more digital voice circuits based on dialed numbers or other criteria. There are various types of switches including PSTN Exchanges (Public Switched Telephone Network Exchanges), PBX (Private Branch Exchanges) and Key Systems. PBXs are used in large enterprises or corporate environments to switch internal calls and enable access to the PSTN, while Key Systems are used for the same purpose in smaller organizations.
Early switches were manually operated. Callers lifted the receiver and asked an operator to connect the call to a specified number. The operator would make the connection by physically plugging the line into a jack on the switchboard that corresponded to the destination number. If the destination was non-local, then the operator would connect the call to a trunk connected to a remote switchboard, and ask the far-end operator to connect the call.
Modern digital telecoms switches use computer processing and electronics to establish phone calls automatically across telephone circuits. This is this is typically controlled using the SS7 (Signalling System 7) protocol, or the SIP protocol in the case of VoIP networks. TDM (Time-Division Multiplexing) technology allows multiple simultaneous calls to be transmitted over a single circuit, dramatically increasing the capacity of the network.
The components of a digital telecoms switch generally include cabinets, logic cards, control cards, power cards, backup batteries, handsets, and trunk connections to remote networks. The latest switches offer a wide range of features such as auto attendant, automatic call distribution, call forwarding, call park, conference calling, direct inward dialing, interactive voice response, music on hold, voicemail and more.
Switch to SpectrumVoIP
With the rise of Internet telephony, IP PBX is becoming increasingly common, and many telecommunications providers like SpectrumVoIP now offer advanced Voice over IP solutions in which the customer’s handsets are connected to a hosted IP PBX over the Internet. These feature-rich solutions are highly cost-effective, with fixed monthly pricing and no upfront costs or hidden charges.