When you’re shopping around for internet service, an internet provider (i.e. AT&T, Comcast) will typically offer many differently-priced service plans depending on how much bandwidth they will provide. This equates almost directly with connection speed and load times, so it’s important to have enough bandwidth to accommodate your browsing habits.
There are two important metrics in bandwidth allocation (measured in Megabits per second or Mbps): upstream and downstream, denoting the speed of outbound and inbound traffic respectively. They are useful for different tasks, so let’s address them separately. All bandwidth suggestions below are for a single user. Obviously if many users are simultaneously sharing a single connection, requirements will increase accordingly.
Downstream Bandwidth
This is the more useful of the two metrics for most residential users. It reflects how much data can be transmitted to your computer/LAN at one time, affecting the speed of web page loading, file downloading, video/audio streaming, etc. For comfortable web browsing, I recommend you have 1-2 Mbps per user. If you watch a lot of YouTube or Netflix or use Pandora or other streaming media service, you probably want more like 4-5 Mbps per user. If you make use of digital software and game distribution services like Steam or frequently download very very large files, then you should spring for 10-20 megs or faster. It will really save on your thumb-twiddling time.
Upstream Bandwidth
Upstream bandwidth plays a more complicated role in internet activity. It is less used, but still very important as it determines how quickly your computer/LAN can transmit data to a remote location. In web browsing and media streaming, its only real function is to send the initial request for web pages and files to the server. After that, all the load is carried on the downstream pipe. For this reason ISPs typically provide much less outbound bandwidth to their subscribers, sometimes as little as 1/10th the inbound.
Upstream bandwidth does have significant impact on certain operations. Does it take a long time to attach files to your email? That’s the limitation of your upload speed. Stuttering in Skype calls? That’s probably a lack of upstream bandwidth (though it could be yours or the person you’re talking to). Though you can theoretically make Skype video calls with 512k upstream bandwidth, you will probably experience poor performance and/or low picture quality. Offsite backup systems like Mozy or Carbonite rely exclusively on your outbound bandwidth to transmit your files to their servers. This is the reason they take so long to complete a full backup.
Sufficient outbound bandwidth is also critical when hosting remotely-accessible services on your LAN. If you use Remote Desktop or LogMeIn or other remote protocol to access your home or office computer while on the road, you should have at least 1 Mbps upstream. 2 Mbps or better is a good idea when accessing remote files via VPN. If you’re hosting a website, you’ll need some significant outbound bandwidth too, but that becomes more complicated because your bandwidth requirements will change depending on how popular your site is. I recommend 2 Mbps or more to start.
The Short and Sweet
If you want affordable general purpose internet and won’t be using any kind of remote access or hosting services, get 2-4 Mbps downstream per user and don’t sweat the upstream speed. But do be aware of these metrics so you can make informed changes going forward.
Table o’ Bandwidth Requirements (Downstream)
| Bandwidth (per user) | What it’s fast enough for… |
| < 1 Mbps | Email Instant Messaging Frustrating Web Browsing MUDs (those old text adventure games, remember?) |
| 1-2 Mbps | Web Browsing Audio Chat Streaming Audio (i.e. Pandora) Online Gaming |
| 3-4 Mbps | Video Chat Streaming Video (YouTube, Netflix, etc.) High Quality Photos Peer to Peer File Sharing Obsessive Facebook Use |
| 5-9 Mbps | Streaming HD Video Porn (see Streaming HD Video) |
| 10-20 Mbps | Digital Software Distribution |
| 20-50 Mbps | Downloading very large files Porn Addiction (see Downloading very large files) |
| 50+ Mbps | Huge households Corporations Small Countries Impatient People |
Table o’ Bandwidth Requirements (Upstream)
| Bandwidth (per user) | What it’s fast enough for… |
| < 256 Kbps | Email & Instant Messaging Web Browsing Audio/Video Streaming SSH Server |
| 512 Kbps | Audio Chat Online Gaming Remote Desktop |
| 1 Mbps | Video Chat Emailing tons of obnoxious photos Hosting a network game (2-4 players) Screen Sharing BitTorrent |
| 2 Mbps | Skype with more than 2 people Hosting a network game (4-8 players) Remote Backup VPN Web server for a small site |
| 3-5 Mbps | Multicast Video Streaming Web server for a mildly popular site P2P Network Hub |
| 10+ Mbps | Making Me Jealous |
