Video: Enhanced Redundancy of ST 2059-2 Time Transfer over ST 2022-7 Redundant Networks

We’re all starting to get the hang of the basics: that PTP is the new Black and Burst, that we still need sync to make studios work and that PTP (IEEE1588) is standardised under ST 2059 for use in the broadcast industry. So given its importance, how can we make it redundant?

Thomas Kernen from Mellanox and Chair within the STMPE standards community takes about his real-lift work on implementing PTP with an eye on redundancy methods

Thomas covers the following and more:

  • Whether 2022-7 works for PTP
  • BMCA Redundancy Model
  • Multiple Grand master use
  • Adjusting to dynamic variations in timing feeds
  • IEEE 1588 v2.1
  • Timing Differences in basic networks

Speakers

Thomas Kernen Thomas Kernen
Staff Software Architect, Mellanox Technologies
Co-chair SMPTE 32NF Network Facilities Technology Committee

Video: How to Build an SRT Streaming Flow from Encoder to Edge

SRT is an enabler for contribution over the internet – whether point to point, or cloud egress/ingress. In recent weeks here on The Broadcast Knowledge we have seen different takes on how SRT, short for Secure Reliable Transport, and RIST can be used including from Open Broadcast Systems.

Here, Karel Boek, CEO of Raskenlund a Norwegian consultancy company for streaming, explains SRT and builds a workflow as a live demo showing how you can implement it quickly and easily. He starts by explaining where SRT sits and what it’s for. SRT makes contribution over the internet possible because it has a very light-touch away of recovering missing packets which are inevitable on internet links. Karel covers Haivision’s creation of SRT and the SRT Alliance that has grown out of that which now boast 350 members. The protocol being Open Source – and now an IETF Draft – means that a lot of companies have been happy to adopt the protocol. There are frequent plugfests, one has just concluded, where vendors test compatibility with the increasing set of features offered in SRT.

‘Secure’ is the ‘S’ in SRT’s name which is because the stream can be easily encrypted as part of the protocol. This is an important aspect in enabling sports and enterprise contribution in the cloud given the security that no-one can watch the feed before it gets to its destination.

‘Reliable’ is the key offer for SRT as that’s the number one problem with the internet and other networks where not all packets get delivered. TCP/IP is a great protocol on which most webpages are delivered. It’s fantastic for file delivery since every single packet gets acknowledged and there really isn’t any way that a file can get to the other end without being completely intact. Live streams can’t afford the overhead of counting in and counting out every packet so SRT’s ability to request only the missing packets is very important. It should be noted that this ability is also in Zixi, ARQ and RIST.

Karel compares SRT with other protocols including RTMP, MPEG-2 Transport Streams amongst others. He is careful to separate HLS, MPEG-DASH and WebRTC as ‘last-mile protocols’ in order to make a differentiation between those which content providers use to move video around as part of production and those which are used for distribution. RTMP’s use is still notable but diminishing particularly in Europe and the American markets. But the idea of MPEG-TS over UDP is still the best way to deliver within a building. Outside of the building, you would then want to protect it at least with FEC, with SMPTE 2022-7 or, better, with a protocol such as RIST or SRT. Karel mentions the details of the Simple Profile of RIST which was, by design, missing the features Karel notes are absent. We’ve heard here on The Broadcast Knowledge that these features have been delivered as planned in the Main Profile.

In the final part of this talk, Karel builds, live, an example workflow which combines both Wowza and SRTHub to create an end-to-end workflow. This is a great way of demonstrating how quickly you can create a workflow with SRT. There are plenty of SRT-enabled encoders and senders which is one of the ways we can judge the success of the SRT Alliance. Similarly whilst Haivision’s SRTHub is a useful product which brings things together in the cloud or on-prem, but Techex’s MWEdge and Videoflow’s DVG can do similar or more, each with their own advantages.

Overwell the takeaway from this talk from Raskenlund is that internet contribution is sorted, it’s now for your to choose how to do it and with whom. To that end, the talk ends with a Q&A from people wondering exactly that.

Watch now!
Speaker

Karel Boek Karel Boek
CEO,
Raskenlund

Video: RIST: Enabling Remote Work with Reliable Live Video Over Unmanaged Networks

Last week’s article on RIST, here on The Broadcast Knowledge, stirred up some interest about whether we view RIST as being against SRT & Zixi, or whether it’s an evolution thereof. Whilst the talk covered the use of RIST and the reasons one company chose to use it, this talk explains what RIST achieves in terms of features showing that it has a ‘simple’ and ‘main’ profile which bring different features to the table.

Rick Ackermans is the chair of the RIST Activity Group which is the group that develops the specifications. Rick explains some of the reasons motivating people to look at the internet and other unmanaged networks to move their video. The traditional circuit-based contribution and distribution infrastructure on which broadcasting relied has high fixed costs. Whilst this can be fully justifiable for transmitter links, though still expensive, for other ad-hoc circuits you are paying all the time for something which is only occasionally used, satellite space in the C-band is reducing squeezing people out. And, of course, remote working is much in the spotlight so technologies like RIST which don’t have a high latency (unlike HLS) are in demand.

RIST manages to solve many of the problems with using the internet such as protecting your content from theft and from packet loss. It’s a joint effort between many companies including Zixi and Haivision. The aim is to create choice in the market by removing vendor bias and control. Vendors are more likely to implement an open specification than one which has ties to another vendor so this should open up the market creating more demand for this type of solution.

In the next section, we see how RIST as a group is organised and who it fits in to the Video Services Forum, VSF. We then look at the profiles available in RIST. A full implementation aims at being a 3-layer onion with the ‘Simple Profile’ in the middle. This has basic network resilience and interoperability. On top of that, the ‘Main Profile’ is built which adds encryption, authentication and other features. The future sees an ‘Enhanced Profile’ which may bring with it channel management.

Rick then dives down into each of these profiles to uncover the details of what’s there and explain the publication status. The simple profile allows full RTP interoperability for use as a standard sender, but also adds packet recovery plus seamless switching. The Main profile introduces the use of GRE tunnels where a single connection is setup between two devices. Like a cable, multiple signals can then be sent down the cable together. From an IT perspective this makes life so much easier as the number of streams is totally transparent to the network so firewall configuration, for example, is made all the simpler. However it also means that by just running encryption on the tunnel, everything is encrypted with no further complexity. Encryption works better on higher bitrate streams so, again, running on the aggregate has a benefit than on each stream individually. Rick talks about the encryption modes with DTLS and Pre-shared Key being available as well as the all important, but often neglected, step of authenticating – ensuring you are sending to the endpoint you expected to be sending to.

The last part of the talk covers interoperability, including a comparison between RIST and SRT. Whilst there are many similarities, Rick claims RIST can cope with higher percentages of packet loss. He also says that 2022-7 doesn’t work with SRT, though The Broadcast Knowledge is aware of interoperable implementations which do allow 2022-7 to work even through SRT. The climax of this section is explaining the setup of the RIST NAB demo, a multi-vendor, international demo which proved the reliability claims. Rick finishes by examining some case studies and with a Q&A.

Watch now!
Speakers

Merrick Ackermans Rick Ackermans
MVA Broadcast Consulting
RIST Activity Group Chair

Video: Benefits of IP Systems for Sporting Venues

As you walk around any exhibitions there seems to be a myriad of ‘benefits’ of IP working, many of which don’t resonate for particular use cases. Only the most extraordinary businesses need all of the benefits, so in this talk, Imagine Communication’s John Mailhot discusses how IP helps sports venues.

John sets the scene by separating out the function of OB trucks and the ‘inside production’ facilities which have a whole host of non-TV production to do including driving scoreboards, displays inside the venue, replays and importantly has to deal with over 250 events a year, not all of which will have an OB truck.

We see that the scale that IP can work at is a great benefit as many signals can fit down one fibre and 2022-7 seamless switching can easily provide full redundancy for every fibre and SFP. This is a level of redundancy which is simply not seen in SDI systems. With stadia being very large, necessitating cable runs of over 500m, the fact that IP needs fewer cables overall is a great benefit.

John shows an example of an Arista switch only 7U in height which provides 144x 100G ports meaning it could support over 4000 inputs and 4000 outputs. Such density is unprecedented and for OB trucks can be a dealbreaker. For sports venues, this can also be a big motivator but also allow more flexibility in distributing the solution rather than relying on a massive central interconnect with a 1100×1100 SDI router in a central CTA.

TV is nothing without audio and the benefits to audio in 2110 are non trivial since with the audio being split off from the video, we are no longer limited to dealing with just 16 channels per video and de-embedding from a video frame any time we want to touch it.

Timing is an interesting benefit. I say this because, whilst PTP can end up being quite complex compared to black and burst, it has some big benefits. First off, it can live in the same cables as your data where as black and burst requires a whole separate cable infrastructure. PTP also allows you to timestamp all essences which helps with lip-sync throughout your workflow.

John leads us through some examples of how this works for different areas finishing by summing up the relevant benefits such as scalability, multi-format, space efficient, and timing amongst others.

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Download the slides
Speakers

John Mailhot John Mailhot
CTO, Networking & Infrastructure,
Imagine Communications