This document provides an introduction and comparison of common audio networking protocols: AVB/TSN, CobraNet, and Dante. It begins with an overview of networking basics using the OSI model. It then reviews each protocol, covering their technical capabilities, setup requirements, and strengths. Key points include AVB/TSN requiring certified switches but providing plug-and-play installation and excellent sync at 1-5ms latency. CobraNet is tried-and-true but has declining adoption and requires a dedicated network. Dante has wide adoption, works on standard networks, and offers flexible routing and redundancy at <0.15-5ms latency. The document concludes that the goal is meeting user needs, and any protocol can suffice
2. Agenda
• Networking Basics
• Technical and Capabilities Overview
– AVB/TSN
– CobraNet
– Dante
• Which one when?
– Hint: It’s not about the standard or the protocol. They
are just a means to an end. Most of the time, any of
the options, when properly configured will do the job.
3. Target Audience:
• Totally new to AV over IT? This may help.
• If you have worked with any of the popular
protocols, your time is better spent in other
sessions
4. Who is this guy?
• Business Development Manager, Almo Pro AV
• In-house technical resource (one of many)
• Here for you as a value add
• Recording Engineer
• Audio Instructor, Director of Education, SME,
System Designer
• Almost enough networking to be dangerous
6. Why audio networking
Old Way
• Everything Point-to-Point or
through matrix switch
• Individual terminations on
every signal path
• Heavy multi-core snakes
• Reconfiguration and growth
not very flexible
• Signal degradation with
distance
• Minimal distribution-related
latency
Audio Networking
• One RJ45 and CAT5 cable for
dozens of signal paths
• Minimal terminations
• One Cat5e / Cat 6
• End points at any network
drop & Soft routing
• Minimal signal loss with
distance
• Potential distribution related
latency
7. Networking Basics
The OSI Model as a Guide
[International Standards Organization
Open Systems Interconnection Model]
8. The OSI Model
• Describe what happens in a network
• Broken down in to 7 “layers”
• Passes down from 7 through 1 & back up
• AV over IT methods vary in application of OSI model
Host
7 Application i.e. (Outlook)
6 Presentation
5 Session
4 Transport
Media
3 Network Routers
2 Data Switches
1 Physical Cat5e Cables, Rj-45 Connectors
9. Physical Layer
• Cables & Connections
• Moving bits from place to place
• Hubs - all data to all ports, created collisions
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network
2 Data
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
10. Data Layer
• Reliable point-to-point data connection without collisions
• Switches – A little “smarter” than a hub
• Data routed to each port as needed based on unique Media Access
Control (MAC) Address
• Long list of addresses with local devices
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network
2 Data Avoid Collisions Switches: MAC Address
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
11. Data Layer (cont.)
• Switch – Can’t separate the network into smaller pieces
• VLANs - Group Physical ports on a switch so they only see each other.
– One way to isolate data on the network.
– Common in CobraNet and earlier AV networking protocols
• Frame – contains MAC address, payload data, etc
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network
2 Data Avoid Collisions Switches: MAC Address, “Frames”
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
12. Layer 3 - Network Layer
• Method to divide network into smaller networks (subnets)
• Connect networks into larger network (your business
network to the Internet)
• One method to keep data of different types separate for
efficiency or security
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network Connects Subnets Routers:
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
13. Layer 3 - Network Layer (IP)
• Allows us to connect across subnets
• IP Address: 192.168.1.15
• IP: Internet Protocol
• Subnet Mask
• Network #, Subnet #, Device Number (Host Number)
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network Connects Subnets Routers: IP
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
14. Layer 3 - Network Layer (Packets)
• {Packets [Frames (MAC address, Payload)]}
• Source IP Address, Destination Address,
DiffServ (Priority info), etc.
Host
7 Application
6 Presentation
5 Session
4 Transport
Media
3 Network Connects Subnets Routers: Packets, IP, “Packets”
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
15. Layer 4 – Transport Layer
• Connection, Data Order, Reliability, Flow Control, Multiplexing
• [Soft] Port Numbers – local routings within a single device or IP address
• Multiple IP protocols
– TCP – Transport Control Protocol
– UDP – User Datagram Protocol
Host
7 Application
6 Presentation
5 Session
4 Transport Reliability TCP / UDP, “Segments”
Media
3 Network Connects Subnets Routers: Packets, IP, “Packets”
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
16. Layer 4 – Transport Layer (TCP vs. UDP)
TCP – Transport Control Protocol
• Reliable – every data packet is acknowledged as it is received
• Useful when 100% accuracy is required over unmanaged network
such as the pubic Internet
• Acknowledgement increases bandwidth consumption and latency
Host
7 Application
6 Presentation
5 Session
4 Transport Reliability TCP / UDP, “Segments”
Media
3 Network Connects Subnets Routers: Packets, IP, “Packets”
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
17. Layer 4 – Transport Layer (TCP vs.UDP)
UDP – User Datagram Protocol
• No confirmation of delivery – so less header info than TCP
• When urgency is more important accuracy
(i.e. Real-time voice & video)
• Disadvantage on
unreliable network
Host
7 Application
6 Presentation
5 Session
4 Transport Reliability TCP / UDP, “Segments”
Media
3 Network Connects Subnets Routers: Packets, IP, “Packets”
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
18. Layers 5 - 7
• Mostly software and application related
• Data moves down through the layers on the way out & back up on
the way in
• Sometimes functions between layers not clear
• OSI model gives us a way to think about and describe the process
Host
7 Application What we interface with (i.e. email, etc)
6 Presentation Conversion for Application (i.e. compression, encryption)
5 Session Establish Connections between hosts
4 Transport Reliability TCP / UDP, “Segments”
Media
3 Network Connects Subnets Routers: Packets, IP, “Packets”
2 Data Avoid Collisions Switches: Frames, MAC
1 Physical Moving Data Cables, Connectors, Hubs, “Bits”
19. Ethernet Timing & Priority Standards
• All audio over Ethernet protocols require Priority, Sequence, & Sync
• Differentiated Services / Quality of Service (DiffServ, QoS)
– Priority by data type (Clock Sync and Audio Packets over Email)
– Traffic prioritized based upon tags in IP Header (Layer 3)
– Priority number assigned by manage switch to each packet
• Real-time Transport Protocol (RTP)
– Keeps data sequenced in the right order
– Time stamp on UDP header
– Works with RTCP (Real Time Control Protocol) for QoS and Sync
– Variation: RTSP (Real Time Streaming Protocol) works on TCP and not UDP
– Does not reserve resources or provide for quality of service
• Precision Timing Protocol (PTP)
– IEEE 1588
– Sub-microsecond accuracy to synchronize subnets
– Layer 2 - Switches provide hardware-based time stamping
21. Audio Video Bridging /
Time Sensitive Networking
• 2012+
• Proponent: AVnu Alliance…
– Interoperable
– precise timing
– low latency requirements
– open standards
• Avnu Founders: Broadcom, Cisco, Harman, Intel,
and Xilinx
• 50+ current Members
• Collection of IEEE Layer 2 standards
22. Standards vs. Protocols (Unofficial)
• Standards:
– Agreed upon underlying
technologies
– that allow things to work
– i.e. Ethernet
• Protocols:
– A methodology
– May utilize standards to
accomplish a function
– Requires standards to
function with other
technologies
– i.e. Email
23. AVB / TSN – The Standard
• IEEE looked at the various standards to make sure
Audio and Video can go across a network and
pulled them together into one standard
• Does not require a dedicated network
– AVB by definition is part of the network
– The media portion is prioritized over other traffic as
part of this definition
– If anything, the audio will not suffer from other traffic,
but non-media will not get the same priority
• Requires AVB certified switch(es)
• Will not pass on non-certified switches
24. AVB - Stream Reservations
• Stream Reservations for AV held by the switch
• Switch reserves up to 75% of bandwidth for
media
• Queue in the switch to hold non-AVB signals
and prioritize AVB over DiffServ
• Guaranteed synch (<0.5ms, 1 Gigabit)
• Simplification - Enable AVB switch command
25. AVB – Setup & Media Compatibility
• Can run other data on same network.
• Can control amount of the bandwidth allocated
to AVB
• Don’t need to set up QoS on the switch
– Saves time
– “Enable AVB”.
• No VLANs to setup
• Changes not in real time / not a real time switch
– Takes a few seconds for switch to setup path through
the network so not real time switch
26. AVB
• Up to 192K / 32 Bit Floating Point
• Multiple Simultaneous Sample Rates
• Channels: Reports vary by mfg
– 400-512+
– Different devices support different channel counts
• Latency 2ms up to 7 hops – some run less
• “Perfect Audio & Video Sync”
• Supports video, control, and any other payload
data across the same network and within
AVB/TSN
28. CobraNet Background
• 1996 by Peak Audio
• 1997 Super Bowl Halftime Show & Disney’s
Animal Kingdom
• Now owned by Cirrus Logic
• Combination of software, hardware and
network protocol
• Layer 2 Protocol compatible with standard
network infrastructure
29. CobraNet Audio
• Up to 64 channels in and 64 channels out
• Up to 96kHz / 24 Bit
• Must match across system
• Audio grouped in 8 channel bundles
• Less at 24 bit
• Channel count expandable by VLAN
30. CobraNet Timing
• Latency is fixed & applies to the entire system
• Latency: 1.33mS, 2.66mS, or 5.33mS
• User definable
• Lower latency yields lower channel counts
• + AD/DA & DSP Latency ≈ 10ms
• Clock accuracy: 10µs for channels originating on the
same switch
• Longer for devices connected to different switches
• “Conductor” [Master Clock]sends out “Beat packet” for
entire system
31. CobraNet Networking
• Dedicated network not required
• Dedicated network recommended
• VLAN’s an option to segment traffic
• Pops, clicks, or dropouts
• Bandwidth use up to capacity of the switch
32. • Many CobraNet (and Dante) devices offer
Primary and Secondary ports
• For redundancy, not to daisy chain off ports
• For automatic cutover in case of network
failure
CobraNet Redundancy
33. • Network & System Design Tools
• Network Design Support
– http://www.cobranet.info/support/design
CobraCad
36. Dante - Background
• 2003 Former team from Motorola starts
Audinate
• March 2015: Passed 200 Manufactures
– 6 months after passing 150
– 20 Million Dante Network Channels – 50% shipped
in last 12 months
• Wide adoption & major events
• Pope Francis, Paul McCartney, Bruce Springsteen, Elton
John, Bob Dylan, Kenny Chesney, Foo Fighters, The Killers,
etc
37. Dante Networking
• Proprietary system of software & hardware
• Licensed technology for use on standard networks
• OSI Layer 3
• Standard Switch OK
– Managed switch preferred
– Will work with AVB switches
• Dedicated Network: No
• Cat5e if only 100Mbs / Cat6 recommended on gigabit
networks
• Keep some bandwidth headroom
– Up to 70% of usable bandwidth for Dante
38. Dante – Basic Audio
• Supported Channel Count: 1024 (512/512)
• Can route individually (Bundles not required)
• 192K / 32Bit
• Supports Multiple Simultaneous sample rates
– Must match between “subscriptions”
– Subscriptions are signal routings from outputs of
one device to inputs on another
• Label-based routing
40. Dante Networking (cont.)
• OSI Layer 3
• DHCP to automatically assign IP addresses
• Plug & Play device discovery
• UDP / IP for speed
• DiffServ QoS
– Priority by data type
– Priority number assigned to each packet at
managed switch
43. Dante – Latency
• Latency: <0.15ms – 5ms
• User adjustable &
constant
• Set in Dante Controller
• Based on network size
• Set at receiver
• Negotiation between
rcvr & xmtr to ensure
high enough
44. • Dante Virtual Soundcard
– Provides routing from individual channels within
internal applications
– ProTools, Cubase, etc
• Dante Via
– Allows a standard Apple Mac or Windows PC to
function as a Dante device
– No Dante enabled hardware required
Other Dante Software
45. • Some Dante (and many CobraNet) devices
offer Primary and Secondary ports
• For redundancy, not to daisy chain off ports
• For automatic cutover in case of network
failure
Dante Network Redundancy
46. AES67 & Other Players
• AES67 – A standard for standards…
– Get DiffServ standards to function together
– May lose advanced functionality
• HQ Net – HARMAN Pro – Control Only
• EtherSound
• QLAN / QSYS – QSC Only
• ANET – AVIOM
• ROCKETNET
• RAVENNA
• H.264
47. Dante with AVB & AES67
• Dante / Audinate uses DiffServ
• Audinate is a member of Avnu Alliance (AVB)
– Will also make available compatibility to AVB
• AES67 – Unifies DiffServ family of protocols
according to commonalities
• Compatible with AES67 & AVB
• Bridging between protocols can exist and
bridge within a device
48. Summary Highlights
AVB / TSN
(Audio Video Bridging)
• Rapid Adoption Growing
• Plug & Play
• Existing networks
• 1-5ms Latency
• Name Based Routing
• Common Control
Application
• Network Setup may take
time for QoS
• Adoption in flux
• Plug & Play implementations
• Standard. Implementation
will vary
• Easy network setup
• Excellent sync & Low latency
• 192K / 32 bit floating point
• 2ms Latency
• Requires certified switch
• Control & Config per mfg
•Tried and true
• Adoption Waning
•Not Suggested with
other network traffic
• One sample rate per
system
• 8 Channel Bundles
49. Conclusion: It’s not about the network…
• The protocols themselves don’t matter as much as what
they allow you to do with the equipment connected to
them
• While Dante, AVB, and CobraNet all have strength and
limitations, they are each flexible enough to meet audio
most demands
• Starting with the protocol and working up to the rest of the
system is backwards
– Customer Requirements → Specifications → Design Options →
Audio Devices & Selection of Network
– “I only work with equipment that has XLR connections…TRS and
Euroblock are not as good.”
(Not the best analogy, but you get the idea.)
50. Additional Considerations
AVB / TSN
(Audio Video Bridging)
Need to run on existing
network
Are able to upgrade network
to AVB/ TSN certified
switches
If CobraNet is already
in place
For audio – any will work. AVB/TSN is the only one that really supports any payload.
Any audio
Anywhere
[Using presets on the matrix]
Reliable point-to-point data connection without collisions
Switches – A little “smarter” than a hub
Data routed to each port as needed based on unique Media Access Control (MAC) Address
Long list of addresses with local devices
Switches – More effient than hubs – but can’t separate the network into smaller pieces
VLANs - Group Physical ports on a switch so they only see each other.
One way to isolate date on the network.
Common in CobraNet and earlier AV networking protocols
Frame – contains MAC address, payload data, etc
Reliable point-to-point data connection without collisions
Switches – A little “smarter” than a hub
Data routed to each port as needed based on unique Media Access Control (MAC) Address
Long list of addresses with local devices
Switches – More effient than hubs – but can’t separate the netowrk into smaller pieces
VLANs - Group Physical ports on a switch so they only see each other.
One way to isolate date on the network.
Common in CobraNet and earlier AV networking protocols
Frame – contains MAC address, payload data, etc
Switches can provide hardware time stamping which allows synchronization, offsets, and corrections. All covered in IEEE 1588
Implemented only on Layer 2 right now (Layer 3 routing down the road)
Can still run on “Layer 3” network, but for now, only devices that are categorized together on layer 2 can share media data
Interoperable across manufacturers
Open standard published by the IEEE for use by anyone without fee
No need to setup VLANs, because it pretty much does it itself in the background
Once setup, <0.5ms latency.
MOTU AVB Switch under $300
http://www.cobranet.info/downloads
http://www.cobranet.info/downloads
Will work with AVB switch – as will pretty much anything since and AVB is a networking standard