What Is SMPTE 2110? How the ST 2110 Standards Suite Works

A single uncompressed 1080p59.94 video stream eats roughly 3 Gbps of network capacity. Push 4K at 60 fps and you’re looking at 8 to 12 Gbps for one camera feed. Those numbers explain why broadcast facilities spent thirty years running coaxial SDI cable instead of Ethernet, and why the move to IP needed a purpose-built standard: SMPTE 2110.

Instead of wrapping a whole SDI signal into IP packets, SMPTE 2110 splits video, audio, and ancillary data into independent streams that travel across a managed IP network and stay locked together by a shared clock. Broadcasters use it to replace SDI routers with commodity Ethernet switches.

One thing most explainers skip: SMPTE 2110 stops at your facility edge. It’s a production and contribution standard, not a way to reach viewers.

What Is SMPTE 2110?

SMPTE 2110 is a suite of standards from the Society of Motion Picture and Television Engineers that transports professional video, audio, and metadata as separate synchronized streams over a managed IP network. SMPTE describes it as the carriage, synchronization, and description of separate elementary essence streams over IP for real-time production and playout.

The word that matters most in that definition is separate. In SDI, one cable carries everything: picture, embedded audio, timecode, captions.

SMPTE ST 2110 breaks that bundle apart into what the standard calls essences. A show with a 4K program feed, 16 audio channels, and a caption track becomes 18 independent streams on the network, each addressable on its own.

That separation is the whole point. An audio engineer can route a single language stem without touching video. A graphics system can subscribe to ancillary data without pulling down 12 Gbps of pixels it doesn’t need.

Routing becomes a network operation rather than a matrix crosspoint.

The suite exists because SDI hit a wall. Every resolution jump meant new cable specs, new routers, and new infrastructure: 1.5G for HD, 3G for 1080p, 12G for 4K.

IP networks scale by adding switch ports. SMPTE published the first four parts of the 2110 suite on November 27, 2017, building on technical recommendations the Video Services Forum released in 2015.

SMPTE 2110 vs SDI vs SMPTE 2022-6

SDI, ST 2022-6, and ST 2110 get confused constantly. The differences shape how you design a facility.

SDI carries a single multiplexed signal over coax. Video, embedded audio, and ancillary data ride together, including blanking intervals that hold no picture information. It’s simple, deterministic, and locked to a fixed bit rate per format.

SMPTE ST 2022-6 was the first serious attempt at SDI over IP. It takes the entire SDI signal, blanking and all, and encapsulates it into RTP packets. Nothing is separated.

You get IP transport with SDI thinking, which makes it good for point-to-point contribution and playout links but awkward for production, where you constantly need to shuffle audio or swap ancillary data.

SMPTE ST 2110 starts over. Only the active picture is transmitted, blanking is dropped, and each essence gets its own multicast stream. Dropping blanking alone cuts bandwidth 15 to 30% versus SDI and ST 2022-6.

For the rest of this guide, ST 2110 and SMPTE 2110 mean the same thing. The industry uses both, and SMPTE’s own documents write it as ST 2110.

How Does SMPTE 2110 Work?

SMPTE 2110 runs on four building blocks: RTP for transport, IP multicast for distribution, SDP for description, and PTP for timing. Here’s the sequence for a single camera feed.

1. The sender splits the signal into essences. A 2110-capable camera or gateway separates active video, each audio group, and ancillary data such as timecode and captions into distinct streams.
2. Each essence gets packetized into RTP. Video packets follow the payload format defined in RFC 4175, which maps raw pixel scan lines directly into RTP payloads with no codec in between.
3. Streams are published to multicast groups. Every essence gets its own multicast address and port, so receivers subscribe only to what they need. This is where IP multicast does the heavy lifting that an SDI router used to do.
4. SDP describes each stream. A Session Description Protocol file tells receivers the format, frame rate, color sampling, bit depth, and timing parameters. Without a matching SDP, a receiver has no idea how to interpret the packets.
5. PTP locks everything to a common clock. Precision Time Protocol, IEEE 1588 profiled by SMPTE ST 2059, stamps every stream against a shared grandmaster with sub-microsecond accuracy. RTP timestamps derived from that clock let a receiver realign video and audio that arrived over different network paths.
6. The receiver reassembles and outputs. A switcher, multiviewer, or gateway subscribes to the streams it needs, buffers them against the PTP epoch, and reconstructs a frame-accurate program.

The timing model is what separates SMPTE 2110 from generic video over IP. Streams don’t have to arrive together. They have to be timestamped together, and the receiver does the rest.

The SMPTE 2110 Standards Suite Explained

The suite is modular. Vendors implement the parts their products need, which is why a 2110 audio interface and a 2110 camera can share a network without implementing the same documents.

ST 2110-10: Timing and System Definitions

This is the foundation every other part depends on. It defines how PTP disciplines senders and receivers, how RTP timestamps relate to the media clock, and what an SDP file must contain.

Get PTP wrong and nothing else in the suite works. That’s why grandmaster design gets more engineering attention than any other part of a 2110 build.

ST 2110-20: Uncompressed Video

Active picture only, no compression, no blanking. It supports resolutions from SD up to 32K, arbitrary frame rates, 8/10/12/16-bit depths, and 4:2:0 through 4:4:4 sampling.

Because there’s no video codec in the path, there’s no encode or decode delay to account for, just packetization and network transit.

ST 2110-21: Traffic Shaping

Uncompressed video is bursty by nature, and bursts stack up across switch hops until a buffer overflows. ST 2110-21 fixes that by defining how evenly a sender must pace its packets, using three classes:

• N (narrow) — tight pacing, may pause during vertical blanking. Typical for hardware senders.
• NL (narrow linear) — constant bit rate with no pause, the most evenly paced option.
• W (wide) — looser pacing for software senders. W receivers accept any sender type.

ST 2110-22: Compressed Video

Not every link can carry 12 Gbps. ST 2110-22 defines constant bit-rate compressed video, and most implementations use JPEG XS, a lightweight mezzanine codec with latency measured in a few video lines rather than frames.

That’s under a millisecond, low enough that it doesn’t disturb a live production, and it’s what makes WAN and cloud 2110 workflows practical.

ST 2110-30 and ST 2110-31: Audio

ST 2110-30 carries uncompressed PCM audio and is built on AES67, so it interoperates with Dante, RAVENNA, and Livewire+ gear already deployed in radio and live sound. Typical configurations run 48 kHz with up to eight channels per stream at packet times of 1 ms or 125 µs.

ST 2110-31 handles transparent AES3 transport. That matters when you need to pass Dolby E or other non-PCM payloads through a facility without an audio codec touching them.

ST 2110-40, -41, and -43: Data, Metadata, and Captions

ST 2110-40 carries traditional SMPTE ST 291-1 ancillary data: timecode, AFD, and legacy caption packets. ST 2110-41 adds a faster metadata framework for data that needs to move at sub-frame rates.

ST 2110-43 carries TTML for captions and subtitles as a first-class stream rather than something buried in the video signal.

SMPTE 2110 vs NDI

NDI and SMPTE 2110 aren’t really competitors. They’re answers to different budgets.

NDI compresses video with a low-latency codec and runs happily on a gigabit office network. Discovery is automatic, setup takes minutes, and a laptop can be a source.

SMPTE 2110 sends uncompressed essences, needs 10 GbE or better, and requires PTP, managed switches, and a control layer before a single frame moves.

If your production needs frame-accurate sync across dozens of sources and pristine picture through many generations, 2110 is the answer. If you need twelve sources on an existing network by Friday, NDI is.

Plenty of facilities run both and bridge between them at gateways.

SMPTE 2110 Bandwidth and Network Requirements

Bandwidth surprises everyone arriving from compressed workflows. These figures cover ST 2110-20 uncompressed video at 10-bit 4:2:2.

Three rules follow from that table.

Use 10 GbE as the floor. A single 10 GbE port comfortably carries one uncompressed HD stream plus its audio and data essences with headroom. Trying to run 2110 on 1 GbE isn’t a tuning problem, it’s arithmetic.

Move to 25 GbE for 4K endpoints. A 12 Gbps stream on a 10 GbE port doesn’t fit. Facilities running 4K either go 25 GbE per endpoint or apply ST 2110-22 compression.

Trunk at 100 GbE. Leaf-to-spine links aggregate dozens of flows. A 25 Gb fiber link carries roughly eight 1080p streams, and spine capacity has to cover the whole leaf.

Switches need IEEE 1588 boundary clock support, non-blocking backplanes, and IGMPv3 snooping that can handle fast multicast joins and leaves. Broadcast deployments standardize on data center silicon from Arista, Cisco, and NVIDIA rather than general-purpose enterprise switches.

Advantages of SMPTE 2110

Per-Essence Routing

You can route audio without touching video. That’s the single biggest operational win.

A shading operator, an audio mixer, and a graphics artist each subscribe to exactly the streams they need, and a change on one doesn’t disturb the others.

Format Agnosticism

An SDI plant needs new routers to go from 1080p to 4K. A 2110 network doesn’t care what resolution the pixels represent. The same switch carries 720p today and 8K later, as long as you have the bandwidth headroom.

Lower Bandwidth Than SDI over IP

Drop the blanking and you save 15 to 30% versus ST 2022-6 for the same picture. Over a facility with hundreds of flows, that’s real switch capacity you don’t have to buy.

Commodity Networking Hardware

SDI routers are single-purpose products with single-vendor pricing. Ethernet switches are a commodity market.

Facilities that made the move get spare parts, competitive bids, and a hardware roadmap driven by the data center industry.

Genuine Multi-Vendor Interoperability

Because the standards are open and published by SMPTE, a camera from one vendor, a switcher from another, and an audio console from a third can share the same network. That’s a different world from proprietary IP schemes.

Near-Zero Processing Latency

There’s no encode or decode step in ST 2110-20, so the only video latency is packetization plus network transit plus receiver buffer, typically well under a frame.

Uncompressed also means no generation loss no matter how many times a signal passes through the plant.

Remote and Distributed Production

Once the signal is IP, the production doesn’t have to sit in one building. Add ST 2110-22 with JPEG XS and you can carry the same essences across a WAN to a control room in another city, which is how a lot of live event streaming operations run now.

Challenges and Limitations of SMPTE 2110

The Bandwidth Bill Is Real

Uncompressed video is expensive to move. A facility with 100 HD sources needs roughly 300 Gbps of capacity before you count audio, data, or return feeds.

Mitigation: apply ST 2110-22 with JPEG XS on links where visually lossless is good enough.

PTP Is a Single Point of Failure

Lose the grandmaster and every device in the plant drifts. PTP also degrades over distance and across poorly configured switches.

Mitigation: deploy redundant GPS-disciplined grandmasters with tested BMCA failover, and enable boundary clock on every switch in the path.

Misconfiguration Fails Silently

Multicast address planning, IGMP tuning, VLAN design, and ST 2110-21 sender profile mismatches all produce failures that look nothing like a bad cable. A wide sender feeding a narrow receiver can pass a bench test and fall over under load.

Mitigation: budget for RP 2110-25 measurement practices and dedicated 2110 monitoring probes.

The Talent Pool Is Thin

Running a 2110 plant means employing people who understand both broadcast engineering and IP networking. Those people are scarce and expensive, and formal SMPTE 2110 training programs are still catching up to demand.

Mitigation: pair a network engineer with a broadcast engineer rather than looking for one person who is both.

You Pay Before You Produce

Grandmasters, PTP-aware switches, 2110-capable gateways, monitoring systems, and an NMOS control layer add up long before any production value appears. Small operations rarely clear that bar, which is why NDI dominates below a certain facility size.

It Doesn’t Reach Your Audience

This one gets underestimated. SMPTE 2110 is a facility and contribution technology built on multicast, which doesn’t traverse the public internet.

Nothing in the suite delivers video to a browser, a phone, or a smart TV. That’s a separate stack entirely.

That last point is where most 2110 projects hit an architectural decision. Understanding the standard is one thing; building the plant and then getting the finished program out to viewers is another.

How to Implement SMPTE 2110

1. Design the Network First

Start with a leaf-spine topology, not the star topology an SDI router implies. Count your endpoints, multiply by per-stream bandwidth, and size leaf uplinks so no spine link exceeds about 70% utilization at peak.

Specify switches with IEEE 1588 boundary clock support and IGMPv3 snooping from the start, because retrofitting timing into a switch fabric isn’t possible.

2. Build the PTP Timing Layer

Install two GPS-disciplined grandmasters with independent antenna feeds and verify BMCA failover under load before anything else connects. Enable boundary clock on every switch so PTP is regenerated hop by hop rather than passed through.

Test how long your receivers take to re-lock after a grandmaster switch. That number is your worst-case outage.

3. Plan Multicast Addressing

Assign a structured address range per essence type and per source so troubleshooting doesn’t turn into archaeology. Document the SDP for every sender.

Teams that skip this step spend their first six months chasing streams they can’t identify.

4. Add an NMOS Control Layer

Raw 2110 has no discovery mechanism. NMOS fills that gap:

• IS-04 registers devices along with their senders and receivers
• IS-05 makes and breaks connections
• IS-06 handles network resource control
• IS-08 maps audio channels

Without NMOS, every route change is a manual SDP edit.

5. Bridge to and from Non-2110 Sources

Almost no facility is pure 2110 on day one. Gateways convert SDI to 2110 for legacy cameras, and convert 2110 to SRT, RTMP, MPEG-TS, or NDI heading outward.

Pick gateway hardware that handles both directions so you aren’t buying two products.

6. Deploy Monitoring Before You Go Live

SMPTE 2110 monitoring isn’t optional. You need probes that track:

• PTP offset across every device
• Packet timing against ST 2110-21 profiles
• Multicast join health
• Per-flow packet loss

In an SDI plant a bad signal looks bad. In a 2110 plant it looks fine until it disappears.

7. Hand Off to a Distribution Platform

Your 2110 network ends at the facility edge. From there, the program feed has to reach viewers, and that means a completely different set of protocols.

Rather than building transcoding, packaging, and CDN delivery yourself, most teams push a contribution feed from a 2110 gateway into a video platform over SRT or RTMP. LiveAPI accepts both, handles encoding into adaptive renditions up to 4K, and delivers over Akamai, Cloudflare, and Fastly through a single API.

Instead of spending months assembling a delivery stack, you point your gateway at a stream key and go live.

# Push a program feed from a 2110 gateway to a streaming platform
ffmpeg -re \
  -i "srt://gateway.local:9000?mode=caller" \
  -c:v libx264 -preset veryfast -b:v 8000k -g 60 \
  -c:a aac -b:a 192k \
  -f flv "rtmps://ingest.liveapi.com/live/YOUR_STREAM_KEY"

From SMPTE 2110 to Internet Delivery

A 2110 facility and an internet audience speak different languages. Here’s what has to happen between them.

Contribution Encoding

The program feed leaves the plant as uncompressed essences and has to become a single compressed stream. A live streaming encoder or 2110 gateway does the compression, typically H.264 or HEVC at a high contribution bitrate, and wraps it in SRT or RTMP for the trip to your platform.

Transcoding and ABR Packaging

One contribution stream can’t serve every viewer. Transcoding produces multiple renditions, and adaptive bitrate streaming lets each player pick the rendition that matches its connection.

This is where a facility-grade signal becomes something a phone on cellular can actually watch.

HTTP Delivery and CDN

HLS segments get pushed to a CDN and pulled by players over ordinary HTTP. Running a multi-CDN setup protects you against a single provider having a bad night during your biggest event, which is standard practice for anything at scale.

Recording and On-Demand

Live doesn’t end when the broadcast does. A live to VOD workflow captures the stream as it airs and makes it available for replay minutes later, without a separate ingest step or a manual upload.

The Build-vs-Buy Line

Each of those stages is a system with its own scaling behavior, failure modes, and on-call burden. Building all four in house is a multi-quarter engineering project before you’ve delivered a single viewer minute.

LiveAPI collapses them into one API:

• RTMP and SRT ingest
• Instant encoding, so recordings are playable in seconds
• HLS output with an embeddable player
• Geo-blocking and domain whitelisting
• Webhooks for stream events
• Pay-as-you-grow pricing based on minutes

Your engineering team keeps its attention on the 2110 side, where the specialized knowledge actually lives.

Is SMPTE 2110 Right for Your Project?

SMPTE 2110 is a serious infrastructure commitment. It pays off in specific conditions and wastes money outside them.

Good fit if:

• You’re building or renovating a facility with dozens or hundreds of sources
• Frame-accurate sync across many devices is a hard requirement
• You need uncompressed quality through multiple production stages
• Your roadmap includes 4K, HDR, or 4K live production at scale
• You want multi-vendor equipment choice instead of a single-vendor router

Not a good fit if:

• You run fewer than about ten sources
• Your network is 1 GbE and there’s no budget to change it
• Nobody on the team has IP networking depth
• Your output is web and mobile only, with no production switching in between
• You need to be on air next month

If you’re in the second column, NDI or SDI plus a video streaming API will get you there faster and cheaper.

And even if you’re squarely in the first column, 2110 handles production, not distribution. You still need a delivery layer.

SMPTE 2110 FAQ

Is SMPTE 2110 a free standard?

The specifications are published by SMPTE and available for purchase, with some documents freely accessible to members. The protocols themselves carry no licensing fee, so any vendor can implement ST 2110 without paying royalties. The cost is in hardware and expertise, not the standard.

What is the difference between SMPTE 2110 and SMPTE 2022?

ST 2022-6 encapsulates a complete SDI signal, blanking included, into IP packets. ST 2110 separates video, audio, and ancillary data into independent streams and drops blanking, which cuts bandwidth 15 to 30% and lets you route each essence on its own.

How much bandwidth does SMPTE 2110 need?

Roughly 2.5 to 3 Gbps for uncompressed 1080p59.94 and 8 to 12 Gbps for UHD 4K at 50 or 60 fps, both at 10-bit 4:2:2. Plan on 10 GbE per HD endpoint, 25 GbE per 4K endpoint, and 100 GbE spine trunks.

What is SMPTE 2110 latency?

Because ST 2110-20 sends uncompressed video, there’s no encode or decode delay. End-to-end latency is packetization plus network transit plus receiver buffer, typically well under one frame. Adding ST 2110-22 with JPEG XS contributes under a millisecond.

Do I need NMOS to use SMPTE 2110?

Technically no, but practically yes for anything beyond a lab. ST 2110 defines transport and timing but not discovery or connection management. NMOS IS-04 and IS-05 supply that control layer, and without them every routing change means editing SDP files by hand.

Can SMPTE 2110 work over the internet?

Not directly. ST 2110 relies on IP multicast and tight PTP synchronization, neither of which survives the public internet. For WAN and cloud workflows, facilities use ST 2110-22 with JPEG XS over managed links, or convert to SRT or MPEG-TS at a gateway.

What network switches support SMPTE 2110?

Data center switches with IEEE 1588 boundary clock support, non-blocking fabrics, and IGMPv3 snooping. Arista 7050X and 7280 series, Cisco Nexus, and NVIDIA Spectrum platforms are the common choices in broadcast deployments.

Does SMPTE 2110 replace SDI completely?

In new large facilities, mostly yes. Most greenfield network and sports plants are being built IP-first. Existing SDI gear stays in service behind gateways, and small operations keep running SDI because the economics of a full 2110 build don’t work below a certain size.

How does SMPTE 2110 handle captions and subtitles?

Two ways. ST 2110-40 carries legacy caption data inside SMPTE ST 291-1 ancillary packets, and ST 2110-43 carries TTML captions as their own stream. Modern builds tend to use -43 for text and -40 for timecode and AFD.

Closing Thoughts on SMPTE 2110

SMPTE 2110 solved a genuine problem. SDI couldn’t scale past 4K without another cable generation, and ST 2022-6 just moved SDI’s limitations onto Ethernet.

Split media into independently routable essences over a PTP-locked IP network and you get a plant that grows by adding switch ports.

The trade is complexity. You’re buying PTP grandmasters, boundary-clock switches, an NMOS control layer, and staff who understand both worlds.

Above a certain scale that math works. Below it, NDI or SDI still wins.

And whichever side of that line you land on, the standard stops at your facility edge. Reaching viewers is a separate stack: contribution encode, transcode, ABR packaging, CDN delivery, and VOD capture.

Ready to get your production online? LiveAPI handles SRT and RTMP ingest, instant encoding up to 4K, HLS delivery across Akamai, Cloudflare, and Fastly, and automatic live-to-VOD recording, all through one API. Get started with LiveAPI.