How Much Bandwidth Does a Live Stream Need?
When a venue says “we have 100M fibre”, do not relax yet. That 100M is download. A stream runs on upload, which at plenty of venues is a fifth of that, and the whole building shares the one line. On a site survey we do not ask whether there is internet. We ask two things: what upload actually measures, and who else is on it.
How much upload to reserve
Left is what the stream itself uses; right is what we ask the venue to set aside. Double, because stream traffic is not flat. Cuts, captions and a pan across the audience all spike it, and the backup stream and director's monitor are on the same line. Reserving just enough is the same as reserving nothing.
| Quality | Stream uses | Ask venue to reserve | Typically |
|---|---|---|---|
| 1080p 30fps | about 6 Mbps | 12 Mbps | Press conferences, briefings, internal training |
| 1080p 60fps | about 9 Mbps | 18 Mbps | Events with movement or performance |
| 4K | 20–35 Mbps | 50 Mbps | Product launches, footage you will crop later |
What the venue's phrases actually mean
| The venue says | What that means | What we ask |
|---|---|---|
| “We have 100M fibre” | That is download. Upload might be 20M, and the whole building shares it | What does upload actually measure? Shared with whom? |
| “There is public Wi-Fi” | The event in the next hall is on the same line | Is there somewhere we can run a physical cable? |
| “The network is reliable” | 50M at ten in the morning can be 8M by two | Can we test at the same time of day as the event? |
| “We are on a corporate network” | Corporate and campus firewalls often block the streaming port | Who runs IT, and can they open it beforehand? |
The firewall one has bitten us. Everything was rigged and the signal simply would not leave the building; it took ages to work out the campus firewall had the streaming port closed. The 4G backup carried the whole event that day. Now we always find the IT person before the survey. One question saves an afternoon.
What we do about it
For events that matter we apply for a separate temporary line: bandwidth to ourselves, physically apart from the venue network. We arrange it, so you never have to deal with the telco. The catch is lead time, which is why we file as soon as the date is fixed.
The 4G backup stays on however solid the main line looks. Switching takes a few seconds; the most viewers notice is a wobble in quality.
When you add up bandwidth, do not stop at the outgoing stream. The director's return feed, remote speakers dialling in and live captions all go over the same line.
Things that speed up the survey if you can find out first
- A measured upload figure, ideally taken at the same time of day as the event
- Whether the network is shared building-wide or a separate line can be run
- Whether a cable can reach the streaming position, and how far it has to run
- Whether the firewall blocks the streaming port, and who the IT contact is
- How many platforms, and whether you want 4K
If you cannot find out, no problem. We bring the meter to the survey.
Not Sure? Let Us Take a Look
Tell us where the venue is and what the event is. Network assessment and arranging the line are part of Network Engineering. How many cameras to bring is covered in our Camera Setup Guide.
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