Modem vs. Router: Understanding the Key Differences

Modems and routers are essential parts of any network topology. However, the former translates analog network signals arriving via cables into a digital format for consumption by endpoint devices. In contrast, the latter manages the distribution of the (already converted) network signals across the entire device landscape. This article explains the differences between modems and routers and looks at some similarities.

Modem vs. Router

Computer networks and the world of information and communication technology (ICT) have evolved rapidly in the past 50 years. Modems and routers were parts of this historical evolutionary phase and continue to be relevant to us today. 

What is a modem? 

A modem is a modulator and demodulator device. It is a computer hardware device that changes data strings from one format to another to facilitate faster and better transmission. It is a piece of hardware that can convert digital information into a format that can be transmitted over an analog transmission medium such as a telephone line, radio, cable, or satellite connection. 

When sending the signal out, a modem modulates it using carrier waves to encode the digital information. In the same way, the receiver of a modem demodulates incoming signals from analog to digital form. 

In simple terms, a modem is like a digital translator that converts information from a cable, telephone line, etc., to a form or language your computer can understand.

When modems first became popular, they were called dial-up modems. These enabled computers to access the internet in the late 1990s and early 2000s. Now, broadband modems are commonly used to connect a computer to a broadband network. 

The key advantages of the modem include:

• They are helpful for the connection of the local area network (LAN) to the internet.
• The cost of getting modems depends on the speed required and can be regulated by the user.
• Modems are now advanced enough to send and receive fax messages.

However, the disadvantages of the modem include:

• It does not maintain data traffic.
• It cannot read the destination of data packets.
• It does not provide security to devices or protect them from cyber threats.

What is a router?

A router is also a hardware tool, a networking device that transfers data packets between computer networks. It connects two or more packet-switched networks, allowing multiple devices to access the internet via the same connection. Routers come in different forms and primarily operate in a LAN environment. Thus, they have several use cases ranging from homes and small enterprises to large companies and organizations. 

Routers work by connecting two or more data lines from different Internet Protocol networks. Small office routers, also used at home, forward these IP packets between the office or home computers and the internet. Larger enterprises use sophisticated routers that forward data at very high speeds across the internet. 

In lay terms, they function as traffic wardens, directing the flow of data on the internet across different routes while ensuring their safety to avoid data loss. Other routers include wireless routers, wired routers, core routers, edge routers, and mesh network routers.

The key advantages of the router include:

• A router provides connections between different network structures.
• It controls and can help analyze network traffic.
• It uses dynamic routing algorithms to select the best route for packets sent over the internet.

However, the disadvantages of the router include:

• It can be pretty expensive.
• Setup and configuration can be quite tasking.
• It cannot operate independently to provide internet access. 

See More: What Is Network Hardware? Definition, Architecture, Challenges, and Best Practices

10 Key Comparisons: Differences and Similarities 

Modems and routers are hardware components found in virtually every office building or home. They provide cheaper, cohesive, and comprehensive internet connectivity to endpoint devices and data centers. However, it can be challenging to differentiate between routers and modems – how to use them, what they do, which one to buy, and when to choose one over the other, etc. By comparing the two, it is clear that there are ten differences between routers and modems and three key similarities.

The differences between modems and routers include:

1. Internet connectivity

Internet connectivity is a necessity that has become indispensable in the 21st century. In the US alone, 307.2 million people, which translates to about 90.8% of the population, are internet users. This translates to thousands of offices, buildings, homes, etc., where the internet is used. Both modems and routers have a role to play in internet connectivity. Specific companies such as AT&T, Xfinity, Verizon, etc., are tasked with providing connectivity, called internet service providers (ISPs). 

A modem is a device that connects a building – for example, an office floor, a restaurant, or a library – to an ISP. It then converts the digital signals to signals that a computer and other machines can understand. A modem is responsible for bringing internet connectivity to a particular location. 

On the other hand, a router cannot by itself bring or enable internet access to computers in any location. A router is tasked with utilizing the internet connection obtained from the modem and making it accessible for all the devices within a mapped-out area. 

2. Working principle of modems and routers

Modems and routers have different principles by which they function. A modem bridges the gap between the digital language computers and phones use and the actual wired transmission done through analog inputs. Wireless modems, also known as radio frequency modems, can do this by converting digital data signals into radio waveforms transmitted over a distance. 

The modem takes a digital signal and modulates it on top of an analog signal or carrier wave. This modulated sine waveform can pass through telephone lines to reach the central internet hub. All these happen at a high-speed rate, which also depends on the modem being used. After modulating and transmitting the data, the receiver part of the modem demodulates the information being sent back. It ‘removes’ the carrier wave leaving the digital form that the computer can interpret. 

A router, on the other hand, works using a different principle. A router is a vital part of the internet supply to the devices in a given space (typically, a building). It creates a local network connecting all the devices to the internet from your ISP through the modem. Without a router, every computer, printer, fax, or laptop needing internet connectivity will need its modem to access the internet directly. 

A router connects devices within a network, transferring packets between those devices and the internet. A router reads the network address information on data packets and then decodes it using its routing table. It then directs the data packet along the correct route to its labeled destination. 

3. Area Network Coverage

Modems and routers make use of different types of area networks. A modem connects to the internet over a wide area network (WAN), while a router connects devices by creating a local area network (LAN). 

Wide area networks, as supported by modems, connect several devices across a vast geographical location worldwide. Internet service providers establish WAN networks. These companies then lease it out to the government, companies, schools, homes, office blocks, etc. Modems have a WAN port through which they send and receive information you are trying to access from the internet. 

A local area network is a network that consists of local devices connected within a defined, enclosed, and single physical geographical location. A typical LAN network consists of computers, smartphones, laptops, tablets, etc., all connected over a single network. LAN can be wired or wireless. However, most company buildings prefer wireless connections due to aesthetics. Routers are used to create and connect these devices over a LAN. Routers can function in a LAN using wired Ethernet and wireless connections. 

See More: Wide Area Network (WAN) vs. Local Area Network (LAN): Key Differences and Similarities

4. Internet protocol (IP) address

An IP address (also known as an internet protocol address) is a series of 4 digits separated by points that act as a unique identifying number for your network. An IP address can be likened to a mailing address. It tells the internet your location on the World Wide Web and enables information to get to you without being misplaced. Modems and routers both make use of IP addresses. However, there are two different types of IP addresses, and this difference applies to modems and routers. 

A modem uses what is called a public IP address as opposed to a private IP address. Every modem is assigned one unique IP address that identifies its location as part of the internet. Public IP addresses are not easily changed. They are set by the ISP to a modem and can be switched on request. A public IP address used in a modem is visible, traceable, and open to the internet except when hidden by a virtual private network (VPN). 

A router is unique and different from a modem because it uses two kinds of IP addresses. Routers use both public and private IP addresses. This is because routers consist of two interfaces, one connects to the WAN via the modem, and another creates a LAN. The WAN interface uses a public IP address just like the modem. In contrast, the LAN interface assigns as many private IP addresses as needed for all the different devices connected to that LAN network.

A private IP address allows devices to connect without being visible on the internet. It is essential for accurately routing data packets within the private network. In practical terms, routers use a private IP address to direct a document sent to your private office printer rather than the general staff printer. 

See More: What Is Network Management? Definition, Key Components, and Best Practices

5. The number of ports 

Ports are sites of potential connection on a device. It is where other devices are plugged into a wired connection. 

A modem has two ports. The first is a service-related port that connects the modem to the service cable from the internet service provider. This port brings the internet into a building or specific area. The second port usually found on a modem is the LAN port which connects to the router’s WAN port. This port takes internet connectivity to the router, and a modem can only connect to one PC using the LAN port. 

A router, on the other hand, has multiple ports. These include an Ethernet port, a WAN port, and USB ports. Most modern routers that ISPs offer have around four Ethernet ports and wireless connectivity. You can also find routers with more than four Ethernet ports. The WAN port or internet port is used to connect to the internet source, usually a modem. The Ethernet ports then distributed that internet across different Ethernet-ready devices for faster data transfers. A router connects to multiple PCs. 

6. Security 

Network security is a very pressing concern for internet users today. The World Wide Web is filled with cyber threats, malicious infections, viruses, and spyware that can not just attack and destroy personal computers but can also be used to steal business and private information. 

Modems do not offer protection from security threats on the internet. This is because it has a public IP address available to all other users on the internet. In addition, modems do not come with an inbuilt firewall. Therefore, a computer directly connected to the internet using modems is exposed to threats on the net except if protective software is installed on that computer. The computer’s IP address can also be traced unless hidden with browsers like Tor or VPN use.

On the other hand, routers provide a good level of security from cyber criminals who can spy on your activities online, monitor your activities and even send malware to your devices. Routers protect the IP address of the devices in their network because they use a private IP address. Depending on the manufacturer, routers may also have firewalls that one can upgrade. 

7. OSI layer of operation 

Modems operate on just the data link layer. The data link layer is the second layer of the open system interconnection (OSI) network architecture model. This network is necessary for transmitting information void of errors. Data link layers operated by modems also bear the burden of decoding, encoding, and organizing data coming into or leaving a network. 

However, routers operate on the data link layer, network layer, and physical layer. The data link layer exists in both routers and modems and works the same way. One can find the network layer (layer three on OSI) in every router and function to examine the headers on all data packets passing through the network. 

Internet protocol is used on the network layer to send data to the correct address. The physical layer is layer one on the OSI model. It deals with transferring bits over a physical connection, either cable or fibers. 

8. Parental control 

Parental control is a feature found in most routers to different degrees. Parental control, however, is not always found on modems. Routers with inbuilt parental control come with features like flexible content filters, time management control, profile setup, ad/pop-up blockers, etc. Parental control features can also come in handy for businesses that may want to regulate internet use at the workplace.

9. Area of coverage 

The area of network coverage is a critical factor that must be considered when making decisions about internet hardware devices such as modems and routers. A single modem should be able to cover about 1600 square feet. This figure may very well vary and reduce due to walls within a building. On the other hand, routers can reach as far as 500 square feet indoors and 1000 square feet outdoors.

10. Wired vs. wireless connections

Modems come in different forms. However, most modems used to supply internet to an enterprise space or large buildings are wired cable modems. However, irrespective of this, wireless modems exist. A typical example of wireless modems is those used in smart mobile phones and personal digital assistants. 

Routers are wired because they must connect to the modem via the router’s WAN port using a cable. Apart from this, they also have Ethernet ports for further wired connections. However, they can provide wireless networks to devices within this coverage area or LAN.

See More: What Is a Mesh Network? Meaning, Types Working, and Applications in 2022

Now that we have discussed the differences between modems and routers, let us consider some of their similarities:

• Physical appearance: To the untrained eye, a modem and a router may look very similar to each other, especially when gotten from the same manufacturer. Closer inspection of the number of ports labels etc., maybe the differentiating factor.
• Function: Both modems and routers are involved or function to ultimately bring internet connection to electronic devices. 
• Form of data transmission: Modems and routers transmit data across their networks similarly, using data packets. Data packets are broken down into pieces of information sent across a network.

See More: How To Make Networks Ready for Cloud-First Era With SD-WAN

Takeaway

Since modems and routers are mandatory components in a network environment, several providers are now combining the two. For instance, Nighthawk by NetGear is a two-in-one cable modem and Wi-Fi switch router that allows users to convert network signals to digital and manage the distribution of signals across endpoint devices. This makes managing and monitoring the network easier while reducing IT clutter. 

Did this article help you understand the differences between network modems and routers? Tell us on LinkedInOpens a new window , TwitterOpens a new window , or FacebookOpens a new window . We’d love to hear from you! 

MORE ON NETWORKING

• What Is a Computer Network? Definition, Objectives, Components, Types, and Best Practices 
• Top 10 Best Practices for Network Monitoring in 2022
• Top 10 Enterprise Networking Hardware Companies in 2022
• What Is Network Topology? Definition, Types With Diagrams, and Selection Best Practices for 2022
• Wide Area Network (WAN) vs. Local Area Network (LAN): Key Differences and Similarities