IEEE 1588

Video: Uncompressed Video over IP & PTP Timing

Posted on by Russell Trafford-Jones

PTP and uncompressed video go hand in hand so this primer on ST 2022 and ST 2110 followed by a PTP deep dive is a great way to gain your footing in the uncompressed world.

In the longest video yet on The Broadcast Knowledge, Steve Holmes on behalf of Tektronix delivers two talks and a practical demo for the SMPTE San Francisco section where he introduces the reasons for and solutions to uncompressed video and goes through the key standards and technologies from ST 2022, those being -6 video and -7 seamless switching plus the major parts of ST 2110, those being timing, video, audio and metadata.

After that, at the 47 minute mark, Steve introduces the need for PTP by reference to black and burst, and goes on to explain how SMPTE’s ST2059 brings PTP into the broadcast domain and helps us synchronise uncompressed essences. He covered how PTP actually works, boundary clocks, Grandmaster/Master/Slave clocks and everything else you need to understand the system,

This video finishes with plenty of questions plus a look at the GUI of measurement equipment showing PTP in real life.

Watch now!
Speaker

Steve Holmes Steve Holmes
Senior Applications Engineer,
Tektronix

Video: Using PTP & SMPTE 2059 A Practical Experience Perspective

Posted on by Russell Trafford-Jones

NAB 2019 saw another IP Showcase with plenty of talks on the topic on many people’s minds: PTP and timing in IP systems. It seems there’s a lot which needs to be considered and, truth be told, a lot of people don’t feel they have the complete list of questions to be asking and certainly don’t know all the answers.

So, here, Greg Shay from Telos talks about the learnings from his extensive experience with timing IP signals and with PTP under SMPTE 2059. He hits the following topics;

  • Must you always have a GPS reference for the PTP master?
  • Are PTP-aware switches always necessary?
  • Can you safely not use PTP Peer Delay requests / responses?
  • What is the effect of internal oscillator tolerance and stability when designing PTP client equipment?

To my ears, these are 4 well placed questions because I’ve heard these asked; they are current in the minds of people who are grappling with current and prospective IP installations.

Greg treats gives each one of these due time and we see some interesting facts come out:
You don’t always need a time-synchronised PTP master (pretending to be in 1970 can work just fine).
Compensating for PTP Peer Delay can make things worse – which seems counter-intuitive to the point of PTP Peer Delay requests.
We also see why PTP-aware switches matter and a statistical method of managing without.

This is a talk which exemplifies IP talks which ‘go deeper’ than simply explaining the point of standards. Implementation always takes thought – not only in basic architecture but in use-cases and edge-cases. Here we learn about both.

Watch now!

Speakers

Greg Shay Greg Shay
CTO,
The Telos Alliance

Video: Scalable IP Architectures for Live Production and Playout

Posted on by Russell Trafford-Jones

For many building a good network for a 2110 or other media-over-IP standards is new and a bit scary. But if there’s one person who knows how to do it, it’s Arista’s Gerard Phillips who’s here to go through the basics and build up the network needed for a large and scalable network.

Scalability is the heart of this, because life does change – your company grows, technology pushes you from SD to HD to UHD etc. So you need to build scalability in from the beginning. Getting this right comes down to choosing the right hardware and having the right architecture.

Gerard looks at switch architecture and bandwidth both in the switch and of the network cables. He then looks towards ‘hub and spoke’ Vs monolithic switch design. What are the pros and cons to each and which is right for you?

SDN – Software Defined Networking – is also a key ingredient in such a network. This is where the routing decisions of the switch infrastructure is taken out of the switches because they have automatic and blinkered algorithms and takes it to a server which has a complete overview of the whole system. For a broadcaster who deals with critical signal chains – this is usually the best approach to give determinism and safety to the network.

PTP – Precision Time Protocol – provides the foundation of the 2110 standard and is therefore very important to studio installations being used to replace black and burst. What are the best ways to distribute this and how can you deal with redundancy?

These topics and more are all covered at this IP Showcase presentation from IBC 2018.

Watch now!

Speaker

Gerard Phillips Gerard Phillips
Systems Engineer,
Arista Networks

Webinar: Network Timing in an IP Infrastructure

Posted on by Russell Trafford-Jones


Time: 08:00 & 16:00 GMT, 20th February 2019

Peter Schut is back in the sixth webinar in Axon’s Broadcast IP 101 series, this time examining timing, namely PTP, for professional essence-over-IP systems such as based on SMPTE ST 2110.

Timing needs to be rock solid in studio settings where many signals are mixed together, so your PTP system needs to be too. SMPTE 2059-2 standardises the use of PTP timecode (IEEE 1588) in broadcast. It’s important to understand how master clocks and slave clocks work, plus there is talk of ‘transparent’ and ‘boundary’ clocks in switches. Getting the architecture right is key remembering that one important different between IP timekeeping and black and burst time keeping is that the communication is two-way.

Peter gives us the benefit of his experience and insight into getting timing right in two sessions, one morning, one evening.

Register now!

Speaker

Peter Schut Peter Schut
CTO
Axon