Internet at the Venue: Wired, Cellular, Bonded and Backup Connections

Most live streams that fail on the day do not fail because of the camera or the encoder. They fail because the internet at the venue was slower, busier or less stable than anyone checked. This guide explains how to measure what you really have, how wired, Wi-Fi and cellular connections behave under load, how bonding combines several connections into one, and how to plan a backup so a dropped line does not end your broadcast.

Upload is the number that matters

Speed tests and venue managers usually quote download speed, because that is what guests care about. A live stream depends on upload: the amount of data your encoder can send out every second, sustained for the whole event.

Plan for an upload of at least one and a half times your stream bitrate, measured at the time of day your event runs. If your encoder sends six megabits per second, look for a sustained nine or more. The headroom absorbs short dips without your encoder dropping frames.

Measure more than once. A speed test is a snapshot of a few seconds, and a venue that tests clean on an empty Tuesday morning can be saturated on a Saturday evening when hundreds of guests share the same line. If you can, run a test stream with your real encoder at your real bitrate for half an hour and watch its dropped-frame counter, not just a speed test.

Wired is still the first choice

A wired Ethernet connection is the most predictable link you can get. Its speed does not change when the room fills, it does not fade behind a wall, and it does not compete with every phone in the audience.

When you talk to the venue, ask specific questions:

• Is there a wired port near the production desk, and is it on a line separate from guest Wi-Fi?
• What upload speed is guaranteed on that port, not just advertised for the building?
• Does the network allow outgoing streaming traffic, or does a firewall block unknown ports and protocols?
• Is there a captive portal or a login page that times out after a few hours?
• Who can you call on the day if the port stops working?

Bring a long network cable and a small switch. The wired port is often across the room from where you want to sit, and the switch lets you connect a second laptop for monitoring without asking for another port.

Venue Wi-Fi and its traps

Wi-Fi can carry a stream, but it is the least predictable option. Its capacity is shared by everyone on the same channel, and it changes from second to second as people move and devices wake up.

Guest networks add traps of their own. Many isolate devices from each other, which breaks tools that need to see a second computer. Captive portals log your encoder out after a set time. Some block the outgoing protocols streaming software uses. If Wi-Fi is the only option, ask for a separate network name for production, sit close to the access point, and test at the time of the event.

Cellular: useful, but crowds change everything

A mobile connection is often the fastest thing you can get at an outdoor event or in an old building, and modern networks can carry a high-quality stream when signal is good.

The catch is that cellular capacity is shared by every phone in range. A stadium, a festival or a conference hall full of guests can turn a fast connection into a crawl just as your event starts. Signal also varies with where you stand, so a router by a window or with an external antenna often performs far better than a phone on a desk.

Check your data plan before relying on it. A stream at a few megabits per second uses gigabytes per hour, and some plans slow down sharply after a threshold.

Bonding: several connections working as one

Bonding spreads your stream over several connections at once, for example two mobile networks and a venue line. A bonding sender splits the outgoing data across all of them, and a receiving server puts it back together in the right order. When one connection slows down or drops, the others carry more of the load.

The benefit is resilience, not just speed. A single cellular link can fail without warning; three links from different operators rarely fail at the same moment. Bonding works best with SRT, because SRT already handles lost and late packets within a fixed delay budget.

The cost is a little extra delay and the need for a receiver on the other end. Plan a larger latency budget for a bonded connection than for a single wired line, so the receiver has time to wait for packets that took the slower path.

Backups: plan for the connection you lose

Even a good connection can fail, so decide in advance what happens when it does. There are three layers of protection, and you can combine them.

1. A second connection. A cellular router next to your wired line lets you switch over in seconds, or join both in a bonded setup.
2. A second encoder. A backup encoder on a separate computer, ideally on a separate connection, keeps the broadcast alive if the main computer or its line fails.
3. A local recording. Record on the encoder or on the camera, so you can publish a complete version later even if viewers saw a gap.

Rehearse the failure once before the event. Unplug the main connection on purpose and watch what your viewers would see from a second device.

Where DCAST comes in

DCAST accepts a stream over RTMP, SRT or WHIP, and the protocol you choose should follow your connection. On a stable wired line, RTMP is the simplest choice. On cellular, Wi-Fi or a long-distance link, SRT is the better fit, and DCAST lets you raise its latency from the default of 500 ms up to 7000 ms when the connection loses packets.

For bonded connections, DCAST receives the stream itself. The SRT settings of a stream include an SRTLA address, which a bonding app on a phone or a bonding sender on a computer can publish to, and the settings suggest a larger SRT latency for this case.

On the PRO and VIP plans, a second encoder can publish to the backup address of the same broadcast. When your main feed is lost, the broadcast continues from the backup with a hitch of a fraction of a second, and your viewers stay in the same player without reloading the page. The backup feed can arrive over SRT as well as over RTMP, so you can run it on a different connection from the main feed.

The step-by-step guide to sending a backup stream from OBS, vMix and Larix shows the encoder settings, and the help page on checking your stream quality during a broadcast shows what to watch while you are live.