Audio-Over-IP in the Broadcast Plant Sco$ Griffin – SVP Engineering, M&E Diversified
Diversified is an industry leader in the design and installa2on of a broad spectrum of custom engineered and integrated audiovisual media delivery solu2ons. They specialize in the use of audiovisual technology for complex and scalable professional broadcast, corporate communica2ons and digital signage networks providing businesses with the enhanced capability of crea2ng, managing and mone2zing original digital content. Holding a degree in Electrical Engineering from Penn State University, ScoE Griffin co-‐founded The Systems Group in 1993 and became SVP Engineering for the Media & Entertainment Division at Diversified in 2016. His extensive career has been focused on the conceptualiza2on and implementa2on of advanced technology for media opera2ons. His design porRolio includes facili2es for news, sports, entertainment, and web content producers, including extensive project work in TV and radio broadcast, film/video/audio post-‐produc2on, mobile event produc2on, content aggrega2on and delivery, corporate communica2ons and narrowcas2ng. ScoE is a member of SMPTE, AES & SVG
Audio-Over-IP in the Broadcast Plant • The IP Advantages • The Formats & Standards • Broadcast System Applica2ons • PiRalls & Perils in Integra2on
The IP Advantages • greater signal robustness (EMI/RFI immunity, no HF loss, voltage drop) • large channel capacity over single lightweight cable • mul2channel bidirec2onal audio & control transport over single cable • commodity infrastructure products can be employed leveraging QoS • IP transport is inherently clocked and can be externally referenced • real2me & non-‐real2me transport supported in same infrastructure • IP mul2cas2ng allows mul2point distribu2on without DAs • integra2on between “pro” and “consumer” gear seamless
• CobraNet
The Formats & Standards
ü first audio-‐over-‐layer-‐2 ethernet streaming ü 100 Mbs point-‐to-‐point ü 64 channels through “bundle assignments” (8-‐channel/bundle) ü delays become an issue in large channel count deployments ü licensing fees
• AVB
ü Ethernet Audio/Video Bridging (eav mode) allows transport with QoS ü 10Gbs data rates supported; point-‐to-‐many-‐point supported ü Stream Reserva2on Protocol (SRP) allows delay minimiza2on and ensures QoS ü Layer-‐2 switching supported (dedicated network segments; “AVB compliant” switches) ü synchroniza2on to master generator (PTP) for lip-‐synch ü open standards (IEEE 802.1) ü plug-‐and-‐play auto-‐discovery
• Dante
The Formats & Standards
ü 512-‐channels bidirec2onal per 1Gb link (64x64 per VSC); 44.1khz-‐192khz sample rates supported ü Layer-‐3 switching supported; QoS managed via Differen2ated Services Code Point (DSCP) ü control layer leveraged for call signaling (e.g. intercom) ü network health monitoring ü plug-‐and-‐play auto-‐discovery (Bonjour) ü Brooklyn-‐2 interface allows AES67 interoperability ü Audinate licensing fees
• Livewire
ü 1Gbs data rates supported; point-‐to-‐many-‐point supported ü control layer leveraged for GPIO (e.g. transport control) ü PTP reference supported in Livewire+ ü plug-‐and-‐play auto-‐discovery (proprietary Adver2sement & Source Alloca2on Protocol) ü Livewire+AES67 allows AES67 interoperability ü Telos Axia licensing fees
• RAVENNA
The Formats & Standards
ü 512-‐channels bidirec2onal per 1Gb link; 44.1khz-‐192khz sample rates supported ü Layer-‐3 switching supported ü Real2me Streaming Protocol (RTSP) used for connec2on management of mul2cast streams ü Session Ini2a2on Protocol (SIP) used for connec2on management of unicast streams (VoIP) ü network health monitoring ü plug-‐and-‐play auto-‐discovery (ZeroConf) ü Brooklyn-‐2 interface allows AES67 interoperability ü no licensing fees
• Q-‐Sys
ü 512-‐channels bidirec2onal per 1Gb link; 44.1khz-‐192khz sample rates supported ü Layer-‐3 switching supported ü Real2me Transport Protocol (RTP) over TCP/IP network ü plug-‐and-‐play auto-‐discovery (proprietary Q-‐Sys Discovery Protocol -‐ QDP)
• AES67
The Formats & Standards
ü Interop standard for audio-‐over-‐IP streaming between the various IP-‐based audio products ü Real2me Transport Protocol (RTP) over TCP/IP network ü Ethernet Audio/Video Bridging (eav mode) allows transport with QoS ü Layer-‐2 switching (enterprise network integra2on supported; interoperability) ü auto-‐discovery NOT standardized -‐ four op2ons; Session Announcement Protocol (SAP) ü PTP (IEEE1588-‐2008) reference standard ü Works in conjunc2on with VSF TR03 as audio transport unique from video and ancillary data
PROTOCOL
Pitfalls & Perils RAVENNA
COBRANET DANTE
ETHERSOUND AVB
Actively Developed
Yes
No
Yes
No
Yes
Uses Standard Network Switches
Yes
Yes
Yes
Yes
No
Multiple Solution Providers
Yes
No
No
No
Yes
Software-only Solutions
Yes
No
Yes
No
Possible
OSI Layer-3
Yes
No
Yes
No
No
Solutions with no ongoing License Fees Yes
No
No
No
Yes
AES67 Compliance
Yes
No
Yes
No
No
Up to 384kHz Sample Rate
Yes
No
No
No
No
Multi-Format Audio Support
Yes
No
No
No
Yes
Broadcast System Applications • microphone snakes with preamp control • large channel count router/mixer interconnect • mix-‐minus crea2on • single-‐wire DAW and processing interconnect • intercom matrix-‐to-‐keypanel connec2ons • radio studio audio/control interconnect • VoIP phone system interfacing (via SIP) • wide area communica2ons trunking & transmission links
Pitfalls & Perils • auto-‐discovery not truly standardized in AES67 • older Dante interfaces not AES67 compliant • Dante Audio streams use the exact same DSCP marking (QoS alloca2ons) as AES67 (and Q-‐LAN) PTPv2 clock traffic -‐ DSCP markings in merged networks may need manual re-‐marking • 32/44.1/192khz not supported in AES67 • AES67 is least common denominator between all other formats • PTP (IEEE1588-‐2008) reference for synchroniza2on • QoS control (DiffServ) for priori2za2on • Layer-‐3 RTP streams for transporta2on