ip signal distribution

IP SIGNAL DISTRIBUTION

Dante, AVB/TSN, and CobraNet:An Introduction and Comparison

Rob Ziv, Business Development Manager, Almo Pro AV

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.

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

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

Show of hands….

Who here has worked with what protocols?

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

Networking Basics

The OSI Model as a Guide[International Standards Organization Open Systems Interconnection Model]

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

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”

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


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”


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


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



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”



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




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


Media




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


Media




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


Media




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

AVB / TSN

“It’s not a protocol, it’s a standard”

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

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

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

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

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

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

CobraNet

“Tried & True…”

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

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

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

http://www.cobranet.info/support/developer/lowlatency

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

• 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

• Network & System Design Tools

• Network Design Support– http://www.cobranet.info/support/design

CobraCad

http://www.cobranet.info/support/design

• Monitoring, Troubleshooting, Maintenance

Discovery Utility “Disco”

“The new kid, that’s not so new”

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

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

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

Dante Controller – Routing

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

Dante Controller – Network Status

Dante Controller – Device Info

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

• 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

• 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

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

http://en.wikipedia.org/wiki/AES67

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

Summary HighlightsAVB / 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

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.)

Additional ConsiderationsAVB / 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

QUESTIONS?

Rob ZivBusiness Development Manager, Almo Pro AV

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