How much upload bandwidth do you actually need?
Comfortably more than your target bitrate, sustained for the whole show. A 1080p60 programme at 9 Mbps wants real headroom above 9 at all times — not a speed test that touched 12 once on a quiet afternoon.
More live streams fail on upload than on anything else, and they fail in a way that looks like a software problem. The encoder starts dropping frames, the picture blocks up, the platform reports a poor connection, and everybody goes looking at settings. The settings are usually fine.
Peak is not the number you need
A speed test opens a connection, pushes as hard as it can for a few seconds and reports the best figure it saw. That tells you what the line can do briefly, on its own, right now. A broadcast needs a figure the line can hold for two hours while somebody else is on a video call and a laptop decides to download an update.
Treat a speed test as an upper bound you will never reach in practice rather than as a capacity you can spend.
How much headroom
Enough that ordinary variation never touches your target. Real bitrate is not perfectly flat — a scene change or a sudden burst of motion costs more for a moment — and other traffic on the connection is not going to wait politely.
So a 6 Mbps programme wants meaningfully more than 6 available, and a 9 Mbps programme meaningfully more than 9, at the worst moment of the day rather than the best. If the honest answer is that you do not have that much, the right response is a lower rung rather than optimism.
The places it goes wrong
Shared venue wifi is the classic. It walks through fine on a Monday when the building is empty and fails during the event it was tested for. If the show matters, get a wired connection or a dedicated segment with capacity reserved for it.
Cellular is viable and genuinely unpredictable — a good signal shares a tower with everybody else on it. This is the case SRT was designed for, and where a wider receive buffer is the difference between a watchable stream and a slideshow.
Asymmetric domestic broadband catches people out because the number everyone quotes is the download. A connection sold on a large download figure may offer a fraction of it upward, and upward is the only direction that matters here.
Test it the way you will use it
Run a real stream, at the settings you intend to use, for longer than you think necessary, at the time of day the show happens, with the building doing what it normally does. Watch for dropped frames rather than for a number.
A ten-minute test at the actual hour tells you more than any amount of speed testing, and it is the only test that includes the other people sharing your connection.
Put it to work on a real show
Venue connectivity is the single biggest production risk at an event, and it is a procurement question weeks ahead rather than a technical one on the day.
Sustained upload from a press box is the decision that determines whether 60 frames is available to you at all.
Related guides
For 1080p30, about 6 Mbps. For 1080p60, about 9. For 720p30, about 3, and 720p60, about 4.5. Frame rate drives the number far harder than resolution does, and your upload has to sustain it, not peak at it.
Use RTMPS on a stable wired line: simple and universally supported. Use SRT when the path is lossy or cellular, because it recovers lost packets. Use WHIP when a browser should publish with nothing installed.