Pipes Are Now Packets

Presenters : Kevin Salvidge - Leader

Year : 2022

dlp_document_download : Pipes are now Packets:What you really need to know about QC monitoring & maintenance for IPKevin Salvidge –Leader Europe Limited §Just remember that IP is just another I/O interface: A way to get video, audio and data to or from a switch§It’s how you do that , that has changed.Pipes are now Packets •Although many broadcasters are transitioning to IP, the majority are going to do so in a piecemeal manner.•With ST-2110, the timing information has been removed from the underlaying hardware layer making the distribution asynchronous.•With current broadcast formats, video must be frame synchronous at the camera’s sensor and at the viewers display device.•The intermediate IP distribution network is asynchronous but the variance in packet jitter directly affects latency leading to potentially longer video and audio delays than we have come to expect from SDI infrastructures.•Although uncompressed video such as that provided by ST-2110 does map to the active video parts of SDI, two major changes have occurred;•The PTP and SPG reference sources may or may not be the same device•Signal distribution in IP is asynchronous and multiplexed. Pipes are now Packets SDI Transmission§In SDI we send Video, Audio and Data all on the same coaxial cable, line by line.§We send a Field or Frame of Video, the Audio that goes with each Field or Frame and the ANC data that goes with that Filed or Frame.HANCAUDIOVANC DataPipes are now Packets IP Transmission§SMPTE ST 2022-6 saw us replicate SDI in a single RTP flow, using UDP Unicast/Multicast protocolsHANCAUDIOVANC DataPipes are now Packets IP Transmission§In IP we send Video, Audio and Data in (3) three different IP Multicast streams (essences).§These different multicast streams can be on the same fiber, but they don’t have to be.VANC DataHANC Audio-40 Data-30 Data-20 DataPipes are now Packets SMPTE ST 2110§ST 2110 uses separate Video, Audio and Metadata as essence payloads, or Flows.§Uses essence over RTP/UDP§Use PTP for synchronization (IEEE 1588 with SMPTE ST 2059-2 Profile.§These three IP flows (essences) make up your program and are aka as a Service Source IP AddressRTP HeaderVideo Payload(RFC 4175)Dest IP AddressRTP HeaderAudio Payload(AES 67)Source IP AddressDest IP AddressRTP HeaderMetadata Payload(IETF)Source IP AddressDest IP AddressST 2110-20 VideoST 2110-30 AudioST 2110-40 DataPipes are now Packets Things we used to do –Analogue Video to SDI.•With Analogue Video, we could hang an Oscilloscope on the video coaxial cable and look at it.•We had to come up with a way to look at SDI, take 10 bits, make a Pixel out of it put that Pixel on the screen.•With Analogue Audio, we could put an Oscilloscope on the Audio and see the Audio.•With SDI we had to come up with a way to grab the channel that we wanted from the data out of the HANC and make an Audio waveform out of it.Pipes are now Packets Things we used to do –SDI to IP.•SDI allowed us to carry the Audio and Captions (and several other things) in the Video payload. New tool sets and new ways were created to look at them.•Well, we have done it again. We have moved everything around and put it on IP, not just IP but (3) three different IP Multicast flows.•We need to find / make new tools to look at Video / Audio / Data (Captions) and make sure the Video / Audio / Captions etc., are compatible with being put back to SDI if needed.•We will look at how to do this and see IP and SDI side-by-side.Pipes are now Packets Engineering verses Day to Day Work.•Engineering IP Trouble shooting:•Yo u n e e d a d e e p t o o l s e t t o t r o u b l e s h o o t t h e I P l a y e r.•IP Flow status, Packet Jitter, PTP timing, Buffers, 2022-7 and more•But that’s not what you need for day-to-day operations•Production Day-to-Day operations;•Waveform, Vector, Captions, SCTE104, Audio Loudness, comparison of IP to SDI feed.Pipes are now Packets SDI Trouble shooting§STATUS§EYE§JITTER§TIMINGPipes are now PacketsStatus, Eye and Jitter and timing are used to measure the integrity of the SDI signal IP Trouble shooting§As IP networks become more complicated, it is important to monitor each service.§Confirm the protocol, data rate, Src. And Dst. address etc. of the received packets§Monitor whether errors in packets occur.§Monitoring traffic on each input IP port, as variations might indicate a network issue.Pipes are now Packets IP Trouble shooting§Excessive jitter results in large variances in inter packet arrival times.§Sustained jitter can mean burst or voids of packets.§If packets are excessively delayed (a void) the receiver is starved.§Receive buffers are drained and the stream cannot be sustained.§If packets are excessively bunched (a burst) the receiver is overloaded§Receive buffers are filled and video data must be discarded.§Use Inter-Packet Arrival tools to visualize packet jitter.Pipes are now Packets Pipes are now Packets •With ST-2110, the timing information has been removed from the underlaying hardware layer making the distribution asynchronous.•BB / TLS reference is replaced by Precision Time Protocol (PTP)•PTP is time-based, as opposed to phase based like BB / TLSPipes are now Packets IP Trouble shooting§PTP works by sending messages in both directions between the Grandmaster and Follower clock (device that is being timed) and using timestamps on those messages to determine the delays in the network and the offset in the client.Pipes are now Packets IP Trouble shooting§One way to look at this, is PTP compensates for network delays and will adjust the Follower clock, using the measured difference in time between the Grandmaster and the Follower in time on the upstream and downstream paths.§So, if the path delay on the two directions of a given path really are equal then the two clocks will be accurately aligned.Pipes are now Packets IP Trouble shooting§Display synchronization status, time information and delay in PTP time synchronization.§PTP STATUS GMID§PTP DOMAIN§Display max, min, measured value per second of PTP lock status, time information, network delay.§Display PTP Message rates§Network delay graph.Pipes are now Packets •Once we are confident that our PTP reference is stable, we can start to investigate the timing of each of the SMPTE ST 2110 Multicast flows.•With ST-2110-20 the video stream only contains the active pixels.•Which brings with it a new series of measurement challenges.Pipes are now Packets Pipes are now PacketsMbitThe start of PTP is normally the same as the start of Black, Line 0, Pixel 0RTP / PTP Timing –ST.2110HANCActive PixelsVA N C Pipes are now PacketsMbitThe start of PTP is normally the same a the start of Black, Line 0, Pixel 0HANCActive PixelsVA N CBut active video starts 21 lines later for 1080i or 42 lines later for 1080pRTP / PTP Timing –ST.2110 Pipes are now PacketsTiming Comparison 1stPacket Arrival Time Pipes are now Packets •If the Timing Comparison displays and the 1stPacket Arrival Time graph are outside the expected timing range and no image is being displayed, there is one further test you can employ.•On the Leader test and measurement products you can switch the ‘Timestamp Mode’ to OFF.•In this mode, the test and measurement device will lock to the 1stPacket of active video. This mode of operation is similar to testing SDI video sources with the External BB / TLS reference lock switched off.•You can leave the test and measurement device in this mode, but other devices on the IP might not be able to lock to the stream. Pipes are now Packets IP Trouble shooting§Tra n s m i s s i o n Errors –Dropped Data§SDI we look at CRC errors§In IP we look at RTP errors§CRC Errors will not pass through an IP SwitchPipes are now Packets IP Trouble shooting§The Event Log now contains a completely new set of fault parameters.§FCS Error§IP CS Error§UDP CS Error§Video RTP Sequence§Mbit Stream 1,2,3,4§Interval Variation 1,2,3,4§PTP ClockClass§Video CMAX§Video VRX§PTP Unlock Error§PTP GMID Exist§Video RTP Timing§Threshold§ANC RTP Timing§ThresholdPipes are now Packets IP Trouble shooting§ST 2110-20 video stream only contains the active pixels.§Video frame rate and sampling rate are determined on the STATUS -> Packet Arrival Time display from RTP timestamp.Pipes are now Packets IP Trouble shooting§By being able to view simultaneously multiple IP analysis tools, engineers can quickly and efficiently identify where the networking issues lies.§Whilst at the same time still having access to the traditional waveform, timing and picture display tools they are familiar with from SDI based facilitiesPipes are now Packets §Every device may show the errors in a picture a little differently, it is all depends on how they build the picture. §In 1080i one IP packet is about ¼ of a line, that’s how much data will be lost for one packet error. §Some are going break up randomly§Some will have lines of bad pixels jumping all over the place§Some will go to black on the error Pipes are now Packets IP Trouble shooting§Picture Breakup§SlicePipes are now Packets IP Trouble shooting§Picture Breakup§Pixel LinesPipes are now Packets IP Trouble shooting§Picture Breakup§BlackoutPipes are now Packets •So, we’ve established that our IP network is operating correctly.•We now need a suite of analysis tools for Day-to-Day production that operate in both IP and SDI infrastructures.•Remember –IP is just another I/O interface –its how we analysis it.Pipes are now Packets Day-to-Day Operations§Although the transport layer has changed, color management of images remains the same.§Camera shaders don’t care if the source signal is IP or SDI§Yo u n e e d t e s t a n d measurement tools that can display both IP and SDI simultaneously (aka as ‘True Hybrid’ Operation) Pipes are now Packets Day-to-Day Operations§The same applies to the traditional ‘Quad-split’ display.§Only the STATUS display is differentPipes are now PacketsSDI StatusIP Status Day-to-Day Operations§With the customizable layout license, analysis tools can be freely sized, positioned and even overlaid depending on the operator preference.§Irrespective of whether the video source is IP or SDIPipes are now Packets Day-to-Day Operations§‘True Hybrid’ operation allows you to ensure ancillary data like closed captions are present.§Multiple analysis tools like PIC and WFM can be displayed in both IP and SDI.Pipes are now PacketsIP C608 Captions608 Captions Day-to-Day Operations§The same applies to Audio Analysis of -30 or -31 audio stream and SDI embedded audio.Pipes are now PacketsSurround Channels missing Day-to-Day Operations§The same applies to ANC Data Analysis of -40 ANC Data stream and SDI embedded audio.Pipes are now PacketsSDI AIP C •Remember –IP is just another I/O interface –its how we analysis it.•IP Networks don’t typically ‘drop off a cliff ’ and fail, they gradually drift.•So having test and measurement products that can monitor your IP network over a prolonged period is vital.•You need tools that will still show you errors that you can relate back to SDI•So having analysis tools that allow you to see Inputs side-by-side, irrespective of whether they are IP or SDI are invaluable.•You need timing tools to verify that your SDI and IP are locked to the same clock•So, connections and analysis of both PTP and BB / TLS are essential.•You need simple user configurable Multi View screen.•The traditional ‘Quad-Split’ display is no longer sufficient.Pipes are now Packets Pipes are now Packets Building a foundation of shared knowledge and practical experience in the area of IP media networkingVisit the Education Library at AIMSAlliance.org Let us know what training and learning opportunities you’d like to see in the field of IP Media Networkinginfo@aimsalliance.orgAIMS Education Working Group If you have any questionsSteve HolmesApplication EngineerTe l : + 1 9 0 9-225-6889Email : holmes@leaderamerica.comKevin SalvidgeSales Engineering ManagerTe l : + 4 4 7 8 2 6-178-752Email :Salvidge@leadereurope.com §If you like more information including a copy of this presentation.Pipes are now Packets Thank You ….. & ….. Any Questions?Kevin Salvidge