Sufficient bandwidth (upload speed) is one of the most important factors in determining whether or not a broadcast will be stable and successful. Every stream has a certain amount of data that is being sent over your local network when you stream and is measured in kilobits or megabits. This rate is almost never a stable value, but will fluctuate from moment to moment across a wave pattern, with highs and lows. The space to send these bit rates fluctuates similarly. Both these rates can be thought of as waves. If the wave representing the bit rate you are sending goes above the wave representing your available network space, your stream will buffer, stutter, or drop.
Ustream Producer offers a feature that will show you when your bandwidth is dipping dangerously low and is threatening to disrupt your broadcast. When your upload bandwidth is adequate to transmit the bitrate of your stream, you will see the bandwidth meter remain at a solid 4 bars. If the bitrate of the stream you are broadcasting exceeds your available bandwidth, you will see green bars go dark and eventually you will see a symbol representing no bandwidth is available. If you see this meter going lower than 4 bars, or showing the no bandwidth symbol, then it is likely your broadcast will disconnect shortly after, unless your available bandwidth quickly recovers.
If you are experiencing this, there are several possible solutions:
- Lower the quality you are broadcasting at
- Ensure you are using a hardwired ethernet connection and not a WiFi connection
- Ensure no one else is using the same internet connection as your broadcast
- Contact your internet service provider to troubleshoot the issue
- Consider switching to a different internet service provider if yours will not provide an adequate level of service.
What are the potential causes of low bandwidth / disconnects in situations where a Speedtest indicates adequate bandwidth?
There may be times when you do a speedtest which shows adequate bandwidth, and you set your bitrate well below your available bandwidth, yet you still experience low bandwidth warnings, buffering, or disconnects. There are several possibilities of why your Speedtest might look good, yet you still experience a symptom of inadequate bandwidth:
- The network is being shared
- The connection to the local network is through wi-fi, or through a 3G/4G signal
- Throttling from an ISP is taking place
The network is being shared
In many cases, you might get access to a location's standard network. You may have done a speedtest beforehand and gotten a good result. However, the situation on the network itself may have changed. If you are the only person on the network when the speedtest is run but more people join the network as the time to broadcast gets closer, the available bandwidth will drop accordingly. A common occurence we see is that you do a speedtest after hours when no one is in the office. It shows 100Mbps upload speed. More than enough to do an HD broadcast. Yet your event occurs the next day, during normal business hours when there are 100 people in the office, all using that same network. Now, with 100 people sharing 100Mbps, your available upload speed is now only 1Mbps, not enough to do an HD broadcast.
The connection to the local network is through wi-fi, 3G, or 4G
Although it is possible and sometimes necessary to stream using a wi-fi or mobile connection, it is not recommended for mission critical, high quality and stable broadcasts if it can be avoided. Wi-fi and cellular networks can frequently cut out and are often shared. Wi-fi and mobile throughput can fluctuate greatly and occur in bursts- this means the data is sent in large chunks with spaces in between. This can result in an encouraging looking speed test, but does not reflect the actual, consistent data rate.
Your ISP (Internet Service Provider) will periodically look for IP addresses that are transmitting unusually large chunks of data. Streaming live video and audio is extremely heavy in terms of a data usage footprint. On occasion, a stream will attract the attention of the ISP. Noticing the unusually large amount of data being sent, the ISP will cut down or 'throttle' the amount of available bandwidth on that network. This will cause a drop in the amount of bandwidth available for the stream, and can have the adverse effects described above.