What is broadband speed ?

Broadband Speed is actually the Latency of a broadband link not the Bandwidth as often advertised. Telcos and the media continually confuse the general public by representing the Bandwidth as a measure of Broadband Speeds. Often to the point that Telecommunication providers advertise each NBN or Broadband Bandwidth tier as the “Speed Tier”.

                 “Bandwidth is not the Broadbands Speed”

What is Broadband Speed ?

Firstly lets determine what speed actually is and what the limiting factors are. For this we need to look a little more closer at what the Internet is, what we are using it for and how that actually works.

When you open your web browser and request a website or url, your device sends out a request to the web server that has the particular site and content you are requestion. That request must travel from your device, across your WIFI connection or LAN cable to your switch. It then travels to your Internet Router and then heads out onto the Internet. Now lets say you are requesting content from the US. That request leaves your router, heads to your capital city in Australia, goes to the Est coast of Australia and then goes under sea via Optic Fibre to the US. Once it gets to the destination server it says to this server “Hey please send me your home page”. Then the home page of this website traverses the exact same path and delivers it to your device and presents it in your browser.

This whole process takes less than a second and we measure the time it takes for the data to traverse from your device to the server you are getting data from. The quicker this time is, the quicker the data will be delivered and the faster your Internet connection will be. This is the Latency

What is Latency?

Latency, on the other hand, is the time it takes for a data packet to travel from the source to the destination. It is usually measured in milliseconds (ms). Factors effecting latency are –

• The distance between you and the service you are requesting
• The various and number of network devices the packet must traverse on this trip
• The medium of the network infrastructure
• Any Network issues encountered
• Speed lost to secure any data networks or packets

Check out PIPs Latency to Australia Capital Cities Page for some examples

What is Bandwidth?

Bandwidth, refers to the maximum amount of data that can be transferred over a network path within a given period. It is usually measured in bits per second (bps) or multiples thereof (Kbps, Mbps, Gbps, etc.).

It describes how much data we can accommodate over a particular medium and/or network infrastructure at any point in time.

Bandwidth Versus Latency – My Analogy

As I look out of my window, I see a major arterial road. It has 3 lanes heading north and 3 lanes south. If we take the 3 northern lanes for our example, this is what would be representative of our bandwidth. The speed limit on this particular road is 80Km/h. This represents our latency. Right now it is fairly quiet on the road and all cars are cruising along at 80km/h.

Now if I went downstairs, and closed 2 of the 3 lanes (reduce the bandwidth by 2/3) the cars would still be travelling at 80km/h as traffic is light. Conversely, I could add 3 more North bound lanes, the cars would still be traveling at 80km/h. No faster. The data package will still take just as long to traverse this section of the network. So increasing or decreasing the bandwidth has ZERO effect on the speed of the data.

When does Bandwidth effect speed ?

Now lets take the above example. We still have our 3 North bound lanes. Its Friday afternoon and everyone’s heading out of Sydney for the long weekend. The traffic is now heavy. The cars out the window are now traveling at 40km/h. Half the speed they can actually go. We have Congestion. Just like on the road, networks too can have congestion. Congestion appears when we try and pull too much data from the Internet at the one time. We typically see this when multiple TVs and/or streaming devices are on a network at the one time. Now if we add 3 more lanes to the road, speed will increase. Just like your Internet, if you are filling all your usable bandwidth and therefore achieving congestion it certainly is time to then increase your bandwidth.

How much bandwidth do I actually need ?

This is simple as all the services, providers and protocols have documented the amount of bandwidth they require and will take up when in use. So you simply need to work out what services in your home or office you need to run concurrently and add up the required bandwidth from the table below.

Where is the Bandwidth Bottle Neck ?

Too often I see many clients increasing their Internet bandwidth on the NBN, but failing to realise their bandwidth is limited else where.

WIFI Bottlenecks

Technology has created the freedom for many of our devices to be cordless providing better user experiences. In this case all the network traffic still needs to be transferred across your home or office network components. Typicality we use some for of WIFI technology for this task. Many WIFI connections are rated ay only 11MBps. It also needs to be remembered that any advertised WIFI speed is the combination of both in and out data AND is shared amongst all devices. It is therefore best practice to keep these devices updated as more mobile devices are added or more cloud services are used.

Check out PIPs WIFI 802.11 Standards, Speeds and Range Cheat Sheet

Ethernet Bottlenecks

Older Ethernet hubs and switches are only capable of transferring 10Mbps. This is the maximum throughput this device can handle at any one time and typically the real figures are much less than those labelled on the front. Just like WIFI this is also the total amount of bandwidth both ways and in a shared environment.

The Differences

While both bandwidth and latency are crucial aspects of network performance, they address different characteristics:

1. Capacity vs. Speed: Bandwidth is about the capacity of the network to handle data, while latency is about the speed at which the data travels.
2. Data Rate vs. Delay: Increasing the bandwidth can allow more data to be transferred per unit of time, but it does not necessarily reduce the latency. Conversely, reducing latency means data reaches its destination faster, but it doesn’t increase the amount of data that can be sent over the network.
3. Network Design: Bandwidth can often be increased by upgrading network equipment, while latency is more dependent on the physical distance between source and destination and the propagation speed of the network medium.

In summary, while both bandwidth and latency are important for a smooth and efficient network, they serve different purposes. Understanding the difference between them can help in designing and troubleshooting network systems.