AES67-101: the Basics of AES67

Presenters : Anthony Kuzub - AIMS

Year : 2018

dlp_document_download : Anthony P. Kuzub IP Audio Product Manager Anthony@Ward-Beck.Systems www.Ward-Beck.Systems TorontoAES.org Vice-Chair AES67-101: The Basics of AES67 SUMMING .audio AMPLIFY .audio FILTERING .audio XLR .audio BUSSING .audio MUTING .audio MATRIXING .audio PREAMPS .audio VUMETERS .audio GROUNDING .audio PANELS .audio DB25 .audio CONSOLES .audio PATCHING .audio Ward-Beck.Systems - Audio Domains The physical datalink networks transported sessions presented by the application The least you SHOULD know about networking: CLOCKING .audio ROUTING .audio MULTICASTING .audio RJ45 .audio 1 - Physical 3 - Network 2 - Data Link 4 - Transport 5 - Session 6 - Presentation 7 - Application TX DATA RX DATA AES67 .audio IGMP .audio 2110-30.AES67 .audio SWITCHING .audio BUSSING .audio MATRIXING .audio PATCHING .audio Livewire QLAN RAVENNA Dante Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Proprietary Proprietary Proprietary Proprietary Proprietary, IPv4 DiffServ L16-32, ≤4 ch/flow PTP1588-2002 44.1kHz, 192kHz HTTP, Ember+ Bonjour RTSP, SIP, IGMP SDP RTP, IPv4 DiffServ L16-32, ≤64 cha/str PTP1588-2008 44.1kHz – 384kHz TCP, HTTP Proprietary Proprietary Proprietary RTP, IPv4 DiffServ 32B-FP, ≤16 ch/str PTP1588-2008 48kHz HTTP, Proprietary Proprietary Proprietary, HTTP, IGMP Channel # RTP, IPv4 DiffServ/802.1pq L24, st, surr Proprietary 48kHz The Road to Incompatibility… AES67-2013 Standard for audio applications of networks: High-performance streaming audio-over-IP interoperability References Audio Engineering Society, New York, NY., US. AES11 - AES recommended practice for digital audio engineering Synchronization of digital audio equipment in studio operations Institute of Electrical and Electronics Engineers (IEEE) IEEE 1588-2008 - IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems, July 2008 Internet Engineering Task Force RFC 768 – User Datagram Protocol" RFC 791 – Internet Protocol RFC 1112 – Host Extensions for IP Multicasting RFC 2236 - Internet Group Management Protocol, Version 2 RFC 2474 – Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers RFC 2616 - Hypertext Transfer Protocol - HTTP/1.1 RFC 2974 – Session Announcement Protocol RFC 3190 – RTP Payload Format for 12-bit DAT Audio and 20- and 24-bit Linear Sampled Audio RFC 3261 - SIP: Session Initiation Protocol RFC 3264 - An Offer/Answer Model with the Session Description Protocol (SDP) RFC 3376 - Internet Group Management Protocol, Version 3 RFC 3550 – RTP: A Transport Protocol for Real-Time Applications RFC 3551 - RTP Profile for Audio and Video Conferences with Minimal Control RFC 4566 – Session Description Protocol RFC 5939 – Session Description Protocol (SDP) Capability Negotiation RFC 7273 – RTP Clock Source Signalling AES67-2018 Standard for audio applications of networks: High-performance streaming a udio-over-IP interoperability Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock AES67 .audio DOMAINS: Device Control Connection Management Transport Timing ROUTING .audio MULTICASTING .audio SWITCHING .audio IGMP .audio AES70 . audio CLOCKING .audio MATRIXING .audio PATCHING .audio AES Standards AES 3 - Serial Digital Audio AES 10 - Serial Multichannel Audio Digital Interface (sMADI) AES 14 - XLR-type polarity and gender AES 59 - 25 pin D-Sub connector AES67 - High-performance streaming audio-over-IP AES70 - Audio applications of networks - Open Control Architecture AES3-1992 AES 10 - MADI AES Recommended Practice for Digital Audio Engineering — Serial Multichannel Audio Digital Interface (MADI) Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Data Rates Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock RTP Packets - Required and recommended packet times EXACT Packet time Packet samples (48 kHz) Packet samples (96 kHz) Packet samples (44,1 kHz) ⅛ millisecond "125 microseconds" 6 12 6 ¼ millisecond "250 microseconds" 12 24 12 "333 microseconds" 16 32 16 "1 millisecond" 48 96 48 "4 milliseconds" 192 n.a. 192 1518 / 1522 1460 12 8 20 14/18 4 Trailer Bytes RTP overhead 12 Bytes IP + UDP + RTP overhead 20 + 8 + 12 = 40 Bytes MTU (maximum transmission unit, largest size of a packet that can be transmitted without being split) 1500 Bytes in an IP/Ethernet LAN: in principle 0 to 1460 bytes available for RTP payload data per packet Layered Packet Encapsulation Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock RTP Packets - Required and recommended packet times SMPTE Toronto Section – Toronto Technical Conference (TTC) 2018 Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock RTP Packets - Required and recommended packet times Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock RTP Packets - Required and recommended packet times Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock RTP Packets - Required and recommended packet times 30 2110- Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock AES67 - RX SHALL SUPPORT 1ms - 1-8 Channels 48KHz - 24bit SMPTE 2110-30 RX CONFORMANCE LEVEL A 1ms 1-8 CH LEVEL B 0.125ms 1-8 CH LEVEL C 0.125ms 1-64 CH ST2110-30 LEVEL A 24bit / 48kHz 1ms 1-8 CH AES67 Mandatory 24bit / 48kHz 1ms 1-8 CH NADI Stadium AES67 Solution: AES67 provides the ability to interconnect entire systems and/or campuses based on different network technology Recording Studio Broadcaster Stage FOH / MON Outside Broadcast Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Connection Change Broken Connection ANEMAN.AES67.audio Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Mix and Match DEVICES IN SUBNET STREAM NAME OF DEVICE STREAM SDP INFORMATION API / MANUAL SDP CH IN STREAM RAVENNA SOURCES NAME + IP ADDRESS CONFIG PTP CONFIG SIP CONFIG SAP CONFIG PCM AUDIO RATE API: STREAM NAME ● TALENT ● MIC ● LINE ● AES ● CITY:BUILDING:FLOOR:STUDIO ROUTING REQUEST SYSTEM CONFIG MATRIXING audio SUMMING audio TX AES67 SDP:JSON CONSUMER NAME ● POOL ● TALENT ● ANALOG ● AES RX AES67 API:CH NAME SDP:JSON Ravenna Bonjour SAP SIP MANUAL SDP RAV2SAP PATCHING audio MULTICASTING audio Automation Controller Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock • device and channel names • network settings • sample rate, bit rate • Status and health monitoring • Status reporting Remote control of device application functions AES70 Ember+ Ember Midi SNMP RS232 RS485 bus Copperlan VISA Eucon Mackie HUI JSON Service Directory Made up - UDP / TCP Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock DISCOVERY.AES67.audio ● SIP - Session Initiation Protocol ● SAP - Session Announcement Protocol ● BONJOUR - apple zeroconf ● AES70 - Connection Management MDNS ● NMOS - ● SNMP ● KLV within stream ● FAST METADATA (SDP extension) Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock NMOS ● Stream identification ● Timing ● Relationships ● Discovery and registration ● Connection management ● JSON data structures Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock v=0 v= (protocol version number, currently only 0) o=- 2 0 IN IP4 192.168.110.178 (originator and session identifier : username, id, version number, network address) s=WardBeck 32ME s= (session name : mandatory with at least one UTF-8-encoded character) t=0 0 t= (time the session is active) a=clock-domain:PTPv2 0 a=* (attribute Clock version and domain) m=audio 50000 RTP/AVP 98 m= (media name and transport port and IP address / RTP profile 98) c=IN IP4 239. 30.178.1/100 c=* (connection information/TTL) a=rtpmap:98 L24/48000/8 a=* (attribute RTP profile / Bit Rate / Sample Rate / Channels) a=framecount: 48 a =* (attribute ) a=sync-time: 0 a=* (attribute required by ST2110-30) a=ptime:1 a=* (attribute: Packet Time) a=ts-refclk:ptp=IEEE1588-2008:EC-46-70-FF-FE-00-8F-C8:0 a=* (attribute) a=mediaclk:direct=0 a=* (attribute) Session Description Protocol Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock a=OCA:1000:1.1.3:OcaBlock:0:1:BLK_Library=Library a=OCA:1001::OcaLibrary:0:1e6:Application= 222 a=OCA:1002::OcaLibrary:0:1e6:Preset= 57575 a=OCA:1003::OcaLibrary:0:1e6:Microphone=23452345 a=OCA:10000:1.1.3:OcaBlock:0:5:preAMP 1=Kick Drum a=OCA:10001:1.1.1.4:OcaSwitch:0:1:Phantom=1 a=OCA:10002:1.1.1.4:OcaSwitch:0:1:Phase_Invert=0 a=OCA:10003:1.1.1.4:OcaSwitch:0:1:Input(MIC/LINE)=0 a=OCA:10005:1.1.1.5:OcaGain:0:63:Pre Amp Gain=45 a=OCA:10100:1.1.3:OcaBlock:0:3:DSP Input 1=2 a=OCA:10101:1.1.1.4:OcaSwitch:0:1:HPF Enable=1 OCA Extended SDP TLV - KLV a=OCA:1000=Library a=OCA:1001= 222 a=OCA:1002=57575 a=OCA:1003= 23452345 a=OCA:10000=Kick Drum a=OCA:10001=1 a=OCA:10002=0 a=OCA:10003=0 a=OCA:10005=45 a=OCA:10100=2 a=OCA:10101=1 http:// MULTICASTING .audio Network Layer(3) : (one-to-many) • Only one connection per stream on transmitter side • Switches copy packets as required • Network traffic increases on last (closest to receiver) segment(s) of network path only • IETF RFC 1112 "Host Extensions for IP Multicasting" Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Control & Monitoring Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock QoS – Differentiated Services (DiffServ) Class name Traffic type Default DiffServ class (DSCP decimal value) Clock IEEE 1588-2008 Announce, Sync, Follow_Up, Delay_Req, Delay_Resp, Pdelay_Req, Pdelay_Resp and Pdelay_Resp_Follow_Up packets EF (46) Media RTP and RTCP media stream data AF41 (34) Best effort IEEE 1588-2008 signaling and management messages. Discovery and connection management messages. DF (0) Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming ynchronization Control & Monitoring Synchronization Media Clock Master Clock (Mode) A clock that is the source of time to which all other clocks in that domain are synchronised Slave clock A slave clock receives the time information from a master clock by synchronizing itself with the master clock. It does not redistribute the time to another clock. In the data center, servers are typically PTP slave clocks. IEEE1588 Precision Time Protocol (PTP) PTP Domain Logical grouping of clocks that are synchronised to each other using PTP, but may not be synchronised to other clocks in another domain Grandmaster clock (GM) A grandmaster clock is the highest-ranking clock within its PTP domain and is the primary reference source for all other PTP elements. Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming ynchronization Control & Monitoring Synchronization Media Clock Ordinary clock An ordinary clock is a PTP clock with a single PTP port. It could be a master clock (grandmaster) or a slave clock. Boundary clock (BC) A boundary clock is the intermediary device between a PTP grandmaster and its PTP slave clients. It has multiple PTP ports in a domain and maintains the time scale used in the domain. Different ports on the boundary clock can be master ports or slave ports. The boundary clock terminates the PTP flow, recovers the clock and time stamp, and regenerates the PTP flow. Effectively, there is a slave port to recover the clock and master ports to regenerate the PTP packets. Transparent clock (TC) A transparent clock measures the time needed for a PTP event message to transit the device and then compensates for the packet delay. IEEE1588 Precision Time Protocol (PTP) Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Control & Monitoring Synchronization Media Clock Delay Mechanism: E2E Announce Interval: 2 secs Announce Timeout: 3 secs Sync Interval: 1/8 sec Delay Req Interval: 1 sec Peer Delay Req Interval: 1 sec Priority 1: 128 Priority 2: 128 Domain: 0 Slave Only: Disabled Announce Timeout – time to wait for an announce message and is a multiple of announce intervals. No announce messages are received within the timeout interval, the unit will assume the role of grandmaster. Sync Interval – Rate that one sync message is sent. The sync and follow up messages are sent from the master to the slave to determine the difference in clock frequency. This information is used in conjunction with the network delay to synchronise the clocks. Delay Req Interval – rate at which a slave clock sends delay request messages to the master. The delay request message allows a slave device to calculate the network delay from the slave to the master. This option is only valid when using the E2E delay mechanism. AES67 PTP Media Profile: Discovery Connection Management Session Description Transport Quality of Service Encoding & Streaming Synchronization Media Clock Control & Monitoring Master Clock Slave Clocks (nodes) Media Clocks PTP SMPTE ST 2059-2:2015 "SMPTE Profile for Use of IEEE-1588 Precision Time Protocol in Professional Broadcast Applications" Grandmaster: The master source of synchronization for clock distribution via PTP. The grandmaster is a network device and is identified by an EUI-64. Media clock: The clock used by senders to sample and receivers to play digital media streams. The media clock for audio streams reads in units of samples. Slave Clock A clock that is synchronized to a master clock (the provider of time) within an environment that uses the Precision Time Protocol (PTP). A slave may, in turn, be a master to another clock and may simultaneously be a boundary clock. A E S 7 0 . a u d i o A E S 6 7 . a u d i o Networking . audio