IPTV internet protocol: what the letters mean and which protocols carry the picture

Short answer: The “IP” in IPTV is the Internet Protocol, the addressing system that moves all data across the internet. On top of it, IPTV services use delivery protocols: HLS for most subscriptions watched in an app, and UDP multicast on networks a telecoms company manages itself. MPEG-TS is the container that holds the video inside both.

Semrush counts about 320 UK searches a month for “iptv internet protocol”, and the phrase hides two separate questions. One is about the name: what the letters stand for. The other is about the plumbing: which protocols actually move the picture from a server to a television.

This article answers both, in that order, and keeps to terms you will meet in real life, such as the endings on a stream link or the settings inside a player app.

What does IPTV internet protocol mean?

IPTV internet protocol means television sent using the Internet Protocol, the set of rules that gives every device an address and moves data between those addresses in small packets. The video is chopped into packets that cross the network like any other data, and a player reassembles them at the other end.

The Internet Protocol itself only handles addressing and delivery of packets. It makes no promise that packets arrive in order, or at all. Other protocols are stacked on top to deal with that, and the choice of which ones to stack is what separates one kind of IPTV from another.

For a wider introduction that goes beyond the protocols, the pillar guide on what IPTV is and how it compares with aerial and satellite is the place to start.

What is the full form of IPTV?

The full form of IPTV is Internet Protocol television. The first two letters name the network method and the last two name what is being carried. Nothing in the name refers to a brand or a particular box. The term has been in use since 1995, and the International Telecommunication Union later gave it a formal definition.

The name is broader than it sounds. Strictly, it covers television delivered over any IP network, and in the industry it often means a service that a telecoms company runs over its own managed lines. In everyday UK use it has widened to include subscriptions delivered over the open internet and opened in a player app.

The two kinds use different protocols, since a managed network can run methods that the public internet cannot carry.

Which protocols does IPTV use to deliver video?

IPTV uses a small family of protocols. HLS delivers video as short files over HTTP and dominates app-based subscriptions. MPEG-TS over HTTP sends one continuous stream. UDP multicast, managed with IGMP, is used inside telecoms networks. Older methods such as RTSP and RTMP survive in specific roles.

Two rows matter to someone with a subscription and a player app: HLS and MPEG-TS over HTTP. The others belong to systems you do not configure yourself.

The split comes down to who owns the wires. A telecoms company that controls every router between its building and your home can use multicast. A service that reaches you across the open internet cannot, so it uses HTTP, which every network already carries.

What is HLS in IPTV?

HLS stands for HTTP Live Streaming. It cuts video into segments a few seconds long and publishes a playlist that lists them. The player reads the playlist and plays the segments back to back. Since everything travels as ordinary web requests, HLS works on almost any connection and any device.

The rules are public. RFC 8216, the HTTP Live Streaming specification, was published in August 2017 as an informational document. It says a playlist is a UTF-8 text file whose address must end in .m3u8 or .m3u, and it lists four formats a segment may use, with MPEG-2 Transport Stream first among them.

HLS has two kinds of playlist. A media playlist lists the segments of one stream. A master playlist lists several versions of the same channel at different bitrates, and the RFC says clients “should switch between different Variant Streams to adapt to network conditions”. That is the mechanism behind a picture that turns soft for a few seconds on a weak connection instead of freezing.

The price of HLS is delay. The same document describes 10 seconds as a typical segment length and tells a player not to start closer than three segments from the live edge, which is 30 seconds on its own.

What is MPEG-TS in IPTV?

MPEG-TS, short for MPEG transport stream, is a container: a way of wrapping video and audio into one stream of small fixed-size packets. It was designed for broadcasting, where signals get damaged in transit, so each packet can be read without the ones around it. IPTV inherited it from digital television.

A container is not the same thing as a codec. The codec, such as H.264 or HEVC, compresses the picture. The container carries the compressed result along with the sound and the timing information that keeps lips matched to words.

MPEG-TS shows up in IPTV in two ways. Inside HLS, each segment is often a small transport stream file. Outside HLS, a server can send one endless transport stream over HTTP with no segments and no playlist, which starts quickly and runs closer to live.

That second method has a weakness. With no playlist there is no list of alternative bitrates, so the player cannot step down when the connection dips. It plays at full quality or it stalls.

What do .m3u8 and .ts mean in an IPTV link?

The ending of a stream link tells you the delivery method. A link ending in .m3u8 points to an HLS playlist, a text file listing segments. A link ending in .ts points straight at an MPEG transport stream. A plain .m3u file is usually a channel list: a text file naming many channels and the link for each one.

The “8” in .m3u8 refers to UTF-8, the text encoding. RFC 8216 requires playlists to use it.

Some player apps ask which output format you want, with a choice between HLS and MPEG-TS. Both play the same channels. HLS copes better with an unsteady connection, while MPEG-TS tends to change channel faster, so the sensible approach is to try one for an evening and switch if it misbehaves.

You rarely need to read these links yourself. With Vivid TV, the login details in your email are typed into the player app, and the app builds the links in the background.

What is UDP multicast in IPTV?

UDP multicast sends a single copy of a channel into the network, and every home that wants it taps into that one stream. A set-top box joins a channel by sending an IGMP message, and leaves it the same way. It is efficient for an operator, because a million viewers cost no more to serve than one.

UDP is the quick, careless sibling of TCP. It sends packets without checking that they arrived and never asks for a resend. For live video that is acceptable, since a packet that turns up late is useless anyway. RTP is often layered on top to number the packets and timestamp them.

Multicast only works where one company controls the whole path. The public internet does not forward multicast traffic between networks, which is why this method stays inside managed services sold with a broadband line, and why an app-based subscription never uses it.

There is one place a home user might see it. Some routers have an “IGMP proxy” or “IGMP snooping” setting, which exists for managed multicast television. Leaving it alone is the right choice for app-based IPTV.

Are RTMP and RTSP still used for IPTV?

RTMP and RTSP are legacy protocols in IPTV. RTMP is still widely used to send a live feed from an encoder into a server, but rarely to deliver video out to viewers. RTSP, which controls play and pause like a remote, survives in older on-demand systems and in security cameras more than in television.

Both come from an era when video needed its own special connection, which routers and firewalls had to be told to let through. HTTP delivery removed that problem. If a player app offers RTMP or RTSP as an input type, it is there for compatibility with unusual sources, not for a normal subscription.

Why does HTTP-based IPTV pass through home routers so easily?

HTTP-based IPTV passes through home routers because it looks exactly like web browsing. Your device makes an outgoing request, and the reply comes back on the connection your device opened. Every home router allows that by default. No port forwarding and no call to your broadband provider is needed.

Routers treat incoming traffic with suspicion and outgoing traffic with trust. A protocol that needs the server to open a connection towards your home runs into that wall. HLS and MPEG-TS over HTTP never do, since the player always asks first.

The same quality lets segments be stored on ordinary web caches close to viewers. The article on what an IPTV server does explains how those copies take load off the origin machine.

Hotel and office networks are the usual exception. Some of them limit video traffic on purpose, and a stream that works at home may fail there for reasons unrelated to the protocol.

Does the protocol matter when you set up or fix IPTV?

For setup, hardly at all. You type the login into a player and the app picks the protocol. For faults it helps a little: knowing that streams are plain HTTP tells you that router settings are almost never the cause, and that a line speed of 10 Mbps for HD or 25 Mbps for 4K is what counts.

For a household, the practical side of IPTV internet protocol is short. A first-time setup needs no protocol knowledge whatsoever, as the walkthrough on how to get IPTV from order to first channel shows.

When something does go wrong, the output format switch is the one protocol setting worth trying, after the basic checks. Those checks, in the order to run them, are on the page about IPTV not working and how to fix it.

Frequently asked questions

What does IP stand for in IPTV?

IP stands for Internet Protocol, the system that addresses and moves data across networks. IPTV is television delivered with it.

Is IPTV the same as internet TV?

Not exactly. Strictly, IPTV means television over a managed IP network, while internet TV travels over the open internet. In everyday UK use the word IPTV covers both.

Does IPTV use TCP or UDP?

App-based subscriptions use TCP, through HTTP. Managed services from telecoms companies often use UDP multicast inside their own networks.

What is the difference between M3U and M3U8?

Both are text playlists. An .m3u8 file is encoded in UTF-8 and is the format HLS uses for segments, while .m3u is commonly used for a list of channels.

Is HLS or MPEG-TS better for IPTV?

HLS handles an unsteady connection better because it can change bitrate. MPEG-TS often changes channel faster. Try both in your player and keep the one that behaves.

Do I need to open ports on my router for IPTV?

No. HTTP-based IPTV uses outgoing web requests, which every home router allows by default.

Read next

• How IPTV channels and categories are organised
• What an IPTV login contains and where to enter it
• Using an online IPTV player in a browser