Presonus Studiolive iii series User manual

StudioLive™ Series III

AVB Networking Guide

www.presonus.com

English

1 Overview

StudioLive™ Series III

AVB Networking Guide

1Overview

Most people who have used a digital mixer in the last ten years are familiar with

incorporating networking technology into their audio application. Remote control

over wireless LAN networks, proprietary audio-over-Ethernet protocols, and

extensible audio networking platforms have all become relatively commonplace.

As networking speed and reliability have increased and the underlying technology

has become more aﬀordable, transporting audio over an Ethernet cable can now

oﬀer dramatic savings of both time and money, making it more attractive than ever.

While there are several protocols currently in use for audio networking, AVB

has many unique beneﬁts that have made it the protocol of choice for the

latest generation of PreSonus pro audio equipment. This tutorial explains

the basics of AVB networking as well as best practices and use cases. While

this guide covers AVB networking in detail for supported PreSonus products,

much of the information here is relevant for other IEEE 1722.1-compliant AVB

devices. PreSonus StudioLive Series III mixers are fully compliant with the IEEE

1722.1 standard, which is the protocol for Discovery, Enumeration, Connection

management, and Control of AVB devices, also known as AVDECC.

Note: Earlier generations of PreSonus AVB products (StudioLive RM-AI and RML-AI mixers,

StudioLive CS18AI, and AI-series consoles equipped with the SL-AVB-MIX option card) are

not 1722.1 AVDECC compliant and can only be used with each other. These products are

not compatible with IEEE 1722.1 devices like the StudioLive Series III mixers or other

third-party AVB products that follow the 1722.1 AVDECC standard.

1 Overview

1.1 What is AVB?

StudioLive™ Series III

AVB Networking Guide

1.1 What is AVB?

AVB (Audio Video Bridging) is an extension to the Ethernet standard designed

to provide guaranteed quality of service, which simply means that audio

samples will reach their destinations on time. AVB allows you to create a

single network for audio, video, and other data like control information,

using an AVB-compatible switch. This allows you to mix normal network data

and audio network data on the same network, making it easier to create

both simple and complex networks. It has been adopted by numerous

audio companies, and more companies are adding it all the time.

Audio-over-Ethernet has become increasingly attractive in Pro Audio

applications especially for distribution in large-scale systems, such as those

used in sporting venues, concert halls, and education institutions. The problem

is that most solutions are proprietary, making these systems too expensive

and too complex for most smaller applications. AVB is intended to change

that by providing an open source collection of IEEE standards available

for use by the pro audio market and its manufacturing community.

AVB networking oﬀers several features that make it ideal for audio applications:

•Long, light cable runs. A single lightweight CAT5e or CAT6 cable can

be run up to 100 meters (328 feet). This makes it easy to have audio

I/O located in diﬀerent rooms (or even diﬀerent venues in the same

building) and run multi-channel audio between them in real time.

•Low, predictable latency. AVB provides latency of no longer

than 2 ms sending an audio stream point-to-point over up to

seven“hops”(trips through switches or other devices).

•Scalable, with high channel counts. AVB’s bandwidth is suﬃcient to carry

hundreds of real-time channels using a single Ethernet cable. This oﬀers the

future possibility of expanding your system with additional devices that contain

diﬀerent kinds of audio I/O, multiple controllers, and other useful functions.

•Integrated clock signal. In a digital audio system with multiple devices,

having a master clock is critical to maintain audio ﬁdelity. The AVB speciﬁcation

deﬁnes such a clock to be accurately distributed to all devices in the system.

1.2 How does AVB work?

On the simplest level, AVB works by reserving a portion of the available

Ethernet bandwidth for its own traﬃc. Because packets of AVB data are

sent regularly in allocated slots within the reserved bandwidth, there are

no interruptions or interference, making AVB extremely reliable.

What makes AVB ideal for audio networking is that it splits network traﬃc into

real-time traﬃc and everything else. All real-time traﬃc is transmitted on an

8 kHz pulse. Anything that’s not real-time traﬃc is then transmitted around

that pulse. Every 125 µs, all real-time streams send their data. Other packets

are transmitted when there is more real-time data ready to be transmitted.

To make sure that there is enough bandwidth available for all prioritized real-

time traﬃc, the Stream Reservation Protocol (SRP, IEEE 802.1Qat) is used.

Every AVB compliant switch between each talker and listener will then make

sure suﬃcient bandwidth is available using SRP, making it a foundational

building block of the AVB standard. Every switch and AVB device on the

network must implement SRP and send real-time traﬃc at the 8 kHz pulse. If

one of the devices on the network does not employ this standard, then real-

time traﬃc could be potentially delayed, causing jitter in the output.

1 Overview

1.3 Timing is Everything

StudioLive™ Series III

AVB Networking Guide

1.2.1 AVB Hardware Components

In an AVB network, every device to and from which audio is ﬂowing must

adhere to the AVB standard. These devices consist of the following types:

•AVB Talkers. These devices act as the source for an AVB

stream, sending out audio onto the network.

•AVB Listeners. These devices are the destinations

for the streams sent out by the Talkers.

•AVB Switches. This is the network hub to which every Talker and

Listener must be connected. At its most basic level, an AVB Switch

analyzes and prioritizes traﬃc on the network. It should be noted

that just like there can be multiple talkers and listeners on the

same AVB network, there can also be multiple AVB Switches.

•AVB Controllers. A controller can be a talker, a listener, or neither. These devices

handle routing, clock, and other settings for AVB devices using AVDECC.

The most important rule to keep in mind when setting up an AVB

network is that the talker (device sending audio) and listener (device

receiving audio) must be connected to an AVB-compatible switch.

All the AVB devices on the network must share a virtual clock that deﬁnes

when the AVB packet should be played. As previously mentioned, devices

communicate on an AVB network as “talkers” and “listeners.” An AVB talker

transmits one or more audio streams to the network. AVB listeners receive

one or more of these streams from the network. It should be noted that an

AVB device, like the StudioLive Series III mixers, can be both a talker and a

listener. For example, StudioLive 32 can simultaneously“Talk” (send channels

out to the network) and“Listen”(receive channels from the network).

AVB devices stay in sync by selecting the best master PTP clock after the

devices connect with one another. This ensures that every AVB device on the

network will maintain precise timing, which is critical to audio quality.

The AVB switch guarantees that real-time audio data packets maintain

their timing without losing information. AVB switches do this by

allowing a maximum of 75% of each port to be used for AVB traﬃc.

This prevents non-AVB data from being delayed or lost.

When an AVB network is conﬁgured, the Talkers and

Listeners identify one another automatically.

1.3 Timing is Everything

All the audio traﬃc on an AVB network is synchronized using a global clock, so

that audio can be played and recorded while remaining in time from multiple

sources. Obviously, the more audio traﬃc on a network, the more critical

this becomes. For users familiar with traditional digital audio devices (ADAT,

S/PDIF, etc.) the idea of a global clocking device will not seem unfamiliar.

PreSonus AVB devices have two clocks: one wordclock and one PTP clock.

All AVB devices on the network are synchronized to a common reference time using

the IEEE 802.1AS Precision Time Protocol (PTP). Each stream includes a presentation

time that all the devices in the network use to align their playback by comparing the

presentation time in each stream packet. An advantage to this design is that AVB

networking supports multiple simultaneous sample rates and sample clock sources

which is important for applications where audio and video need to be synchronized,

even though they travel along diﬀerent paths with diﬀerent sample rates.

1 Overview

1.3 Timing is Everything

StudioLive™ Series III

AVB Networking Guide

1.3.1 Wordclock

Analog audio is transferred through a cable as a continuous electrical

waveform at almost the speed of light. Because of this, audio signal traveling

from one analog audio device to another arrives nearly instantaneously,

for all practical purposes. Therefore, you don’t have to synchronize analog

audio passing from one analog device to other analog devices.

Transferring digital audio is a very diﬀerent matter. Computers and other

digital devices operate one step at a time, which happens very quickly but it’s

not instantaneous, and digital signals are not inherently in perfect time. While

uncompressed digital audio plays at a ﬁxed rate (i.e. the sampling frequency), digital

clocks are not perfect; their frequency can drift, and they almost always have at

least some irregular errors, known as jitter. Therefore, two devices, each following its

own clock, are highly unlikely to stay in agreement about precisely when a sample

starts and ends. The result is usually an artifact, like a pop or a glitch in the audio.

To avoid this problem, all digital devices in communication with one another

need to follow a single master clock. That means the master clock must send a

signal that essentially says,“everyone start at this moment and follow me!”

Even if the master clock’s timing is imperfect, all the slave devices will

follow the timing errors exactly and will stay in sync with each other,

eliminating timing-related artifacts. In general, the better the master clock,

the better the resulting audio will sound, so whenever possible, use the

best clock you have, or experiment with your rig to ﬁnd the best result.

Whenever digital audio devices are synchronized, it is necessary to designate

one device as the“master” wordclock device to which all other digital devices

are synced, or“slaved.” Once you’ve determined which device is to be your

master clock, you will need to sync the remaining digital devices.

The problem of designating a master wordclock is not handled by AVB and must

be set with an AVB controller. This can either be done manually, by the user, or

is ﬁxed by the ﬁrmware of the device. In the case of the latter (as when using

a StudioLive Series III rackmount mixer as a stagebox for a StudioLive Series III

console mixer), this function is not exposed to the user and is set automatically.

Multiple unrelated wordclocks can co-exist on an AVB network. While there are

a few ways to match wordclocks between a talker and listener, PreSonus AVB

devices only support recovering the wordclock by listening to an AVB stream.

1 Overview

1.3 Timing is Everything

StudioLive™ Series III

AVB Networking Guide

1.3.2 Precision Time Protocol (PTP)

Precision Time Protocol or PTP is used to synchronize clocks throughout a

computer network. PTP is capable of achieving clock accuracy in the sub-

microsecond range, making it suitable for local area networks that require

tight timing. Similar to wordclock, PTP uses a master-slave architecture

for clock distribution. This protocol deﬁnes clock master, link delay and

network queuing (both measurement and compensation), as well as

clock-rate matching and adjustments for Layer 2 network devices.

In this architecture, there are several diﬀerent clock types:

•Ordinary Clock. This is a device with a single network connection and

either the sync source (master) or the sync destination (slave).

•Boundary Clock. This device has multiple network connections and can

accurately synchronize one network segment to another. A master clock

is selected for each segment in the system using a root timing reference

generated by the grandmaster clock. The grandmaster sends synchronization

information to the all the clocks on its network segment. The boundary clocks

on that segment then send accurate time to other network segments to which

they’re connected. Every AVB Talker is required to be capable of functioning as

the grandmaster, however any network node can be the grandmaster, as long

as it can either source or derive timing from a grandmaster-capable device.

On an AVB network, PTP generates timestamps so that every listener knows

when to playback the audio from the talker. In other words, the PTP clock is

used to align audio samples from multiple sources in time. Each grandmaster-

capable device broadcasts its clocking using announce messages. The best

master clock is then selected from the available announce messages.

1.3.3 Multiple Stream Reservation Protocol (MSRP)

Multiple Stream Reservation Protocol (MSRP) is the IEEE standard used to reserve

stream bandwidth for audio on an AVB network. This allows endpoints to

automatically route data and reserve bandwidth and eliminates the need for the

user to manually conﬁgure Quality of Service (QoS) across network devices. MSRP

looks at the end-to-end bandwidth that is currently available before an audio stream

is sent out. It then reserves a maximum of 75% of the total bandwidth available

on that AVB switch’s port. If the bandwidth is available, it is locked down along the

entire data path, from the Talker, out to every assigned Listener until it is released.

Bandwidth reservations are made based on talker and listener declarations

on the switch ports. Talker declarations come in several forms:

•Advertise Declaration. This declaration announces that a stream doesn’t

have any bandwidth or network constraints on its designated path. This means

that any destined Listener can create a reservation for QoS. Talker advertise

messages contain all the information necessary to make the reservation.

•Failed Declaration. As its name indicates, this announces that a

stream is not available to a Listener because the necessary bandwidth

is not available or because of other limitations somewhere in the

network path between the Talker and the destined Listener.

As mentioned earlier, Listeners also make declarations within

an AVB network. These consist of the following types:

•Ready. One or more Listeners are requesting a stream and

suﬃcient bandwidth and resources are available from the talker

along the network path to every intended listener.

•Ready Fail. In this instance, one or more Listeners are requesting a

stream, but not all of them have suﬃcient bandwidth and resources

on path to the Talker. In other words, at least one Listener has

encountered an obstacle and at least one Listener has not.

1 Overview

1.3 Timing is Everything

StudioLive™ Series III

AVB Networking Guide

•Fail. When a Fail declaration is sent, one or more Listener has requested

a stream and every Listener that has done so does not have suﬃcient

bandwidth or resources in the network path to attach to the desired stream.

End-to-end stream reservation is successful as soon as the Listener receives the

Talker’s Advertise Declaration and the Talker receives the Listener’s Ready Declaration.

AVB streams are only forwarded once a successful reservation is made. After the

streams stop, switch resources are then released and the process can begin again or

make room for other network traﬃc. In this way, the AVB standard ensures that audio

data streams always have the highest QoS and all other data is secondary or tertiary.

MANUFACTURINGDATE

DESIGNEDANDENGINEEREDINBATONROUGE,LA,USA•MANUFACTURED IN CHINA • PATENTS PENDING • “STUDIOLIVE”

and“PreSonus”AREREGISTEREDTRADEMARSKOFPRESONUSAUDIOELECTRONICS• SD LOGO IS A TRADEMARK OF SD-3C, LLC

MANUFACTURINGDATE

DESIGNEDANDENGINEEREDINBATONROUGE,LA,USA•MANUFACTURED IN CHINA • PATENTS PENDING • “STUDIOLIVE”

and“PreSonus”AREREGISTEREDTRADEMARSKOFPRESONUSAUDIOELECTRONICS• SD LOGO IS A TRADEMARK OF SD-3C, LLC

AVB Switch

Talker

Advertises

Talker

Ready

Talker

Sends Stream

Ready!

Listener

Receives

Listener

Ready

Listener

Receives

Stream

1 Overview

1.4 Overcoming Latency

StudioLive™ Series III

AVB Networking Guide

1.4 Overcoming Latency

SRP works with the 802.1Qav Queuing and Forwarding Protocol (Qav) to ensure that

once bandwidth is reserved for an AVB stream, it is locked down from end to end.

Qav schedule time-sensitive streaming information to minimize latency. Together,

SRP and Qav make sure that all reserved media streams are delivered on time.

In this way, the AVB network has some intelligence as to how much non-media

traﬃc as well as how many media packets are on the system at any given

time. This means that on an AVB network, the worst case travel time is known

throughout the entire system. Because of this, only a small amount of buﬀering

is needed, lowering latency to 2 ms over seven switch hops on a 100 Mbps

Ethernet network. On gigabit networks, even lower latencies can be achieved.

1.5 Channels and Streams

AVB Streams can be thought of as the pipeline that carries a predeﬁned

number of channels between two or more AVB devices. In a PreSonus

StudioLive Series III mixer, for example, there are seven input streams and

seven output streams are available, each carrying eight channels.

It should be noted that each stream can carry any combination of eight channels.

Channel 1

Channel 2

Channel 3

Channel 4

Channel 5

Channel 6

Channel 7

Channel 8

AVB STREAM

2 AVB Networking Basics

1.5 Channels and Streams

StudioLive™ Series III

AVB Networking Guide

2AVB Networking Basics

AVB networks behave very much like an analog audio system.

Like an analog audio system, audio networks consist of sources,

destinations, and intermediate processing along the way.

Let’s look at a simple live-sound setup:

mic stagebox

mixer

active sub

active

loudspeaker

In the above example, an audio signal goes out of the microphone and into the stage

box. It then goes to the mixer, where the microphone signal is ampliﬁed, routed to

the appropriate output, and sent to an active subwoofer, where it is ﬁnally passed

through to the full-range loudspeaker. All of this is readily apparent to any audio

engineer just by looking at the diagram—a good thing because the skills needed to

conﬁgure an analog system are nearly identical those needed by a network engineer.

Let’s compare the audio system above with components in a network:

mic

mixer

Mac

AVB Switch

Input

Processing

Input & Output

Link PoE

Blue=PoE On

(Holdto toggle)

White=PoE O

1 2345

SW5E

AVBSWITCH WITH P

PoE

Link PoE

Because experienced audio engineers understand signal ﬂow and are used

to troubleshooting problems in an analog system at the various points of

weakness, conﬁguring an audio network becomes that much easier.

2 AVB Networking Basics

2.1 Selecting the Right Switch

StudioLive™ Series III

AVB Networking Guide

2.1 Selecting the Right Switch

By deﬁnition all AVB switches must adhere to every IEEE standard within the

AVB protocol. This separates them from ordinary LAN switches (managed or

unmanaged) which do not have this requirement. The PreSonus SW5E adheres

to the AVB standard and provides Power Over Ethernet (PoE) for devices that

require it. This 5-port switch is compatible with all PreSonus AVB devices.

All AVB Switches are required to support the following:

•IEEE 802.1Q: Stream Reservation Protocol (SRP) and Traﬃc Shaping (FQTSS)

•IEEE 802.1AS: Time Synchronization using Generalized Precision

Time Protocol (gPTP) on each AVB enabled Ethernet port

2.2 Adding a Wireless Router

Many modern digital audio devices support some level of control over a Local Area

Network. Unlike its AVB counterpart, a standard LAN network does not prioritize the

traﬃc on it. While this is ﬁne for control information and other simple data, it is less

than ideal for transmitting low-latency audio. PreSonus StudioLive Series III mixers

support both AVB and LAN networking, each with its own dedicated Ethernet port.

For StudioLive Series III mixers, the Audio Network connection

should attach to the AVB network, while the control port should be

connected to a wireless router, or an access point, so that the mixer

can be controlled remotely from UC Surface or QMix-UC.

Link PoE

Blue= PoE On

(Hold to toggle)

White= PoE Oﬀ

1 2345

SW5E

AVB SWITCH WITH P

PoE

Link PoE

2 AVB Networking Basics

2.3 Choosing the Right Cables

StudioLive™ Series III

AVB Networking Guide

It should be noted that while a wireless router can be connected to an

AVB switch, you would still need to connect both the Audio Network and

the Control port to a network conﬁgured in this manner. Because of this,

PreSonus recommends that you create two networks for your StudioLive

mixer: one dedicated to control data and a second dedicate d to AVB data.

2.3 Choosing the Right Cables

Just like a traditional analog audio system, the correct cables can make or break

an AVB network. Be sure to use CAT5e or higher (CAT6 or CAT7) network cable.

The CATE5e speciﬁcation supports transmitting data up to 100 meters but

cable and termination quality, as well as the environment in which the cable

is used, can shorten this potential transmission distance. If you are making the

connections yourself, it is important to note that if the cable is not properly

terminated, it will not be capable of the maximum transmission distance.

Power User Tip: CAT5e cable checkers can verify long-distance transmission

performance. These tools are readily available through many electronics and online

retailers.

Another thing to keep in mind when selecting Ethernet cable is whether it

is solid- or stranded-core. In a solid-core cable, each of the conductors is a

single copper wire, which is a better ﬁt for installations and long cable runs

(more than 70m). Stranded-core cables use multiple, thinner copper wires

for each conductor, making them more ﬂexible and easier to handle. This

makes stranded-core cable a better ﬁt for touring and shorter cable runs.

MANUFACTURINGDATE

Link PoE

Blue= PoE On

(Hold to toggle)

White= PoE Oﬀ

1 2345

SW5E

AVB SWITCH WITHP

PoE

Link PoE

StudioLive 16

StudioLive 32R

SW5E AVB Switch

iPad running UC Surface

2 AVB Networking Basics

2.3 Choosing the Right Cables

StudioLive™ Series III

AVB Networking Guide

Inside your Ethernet cable

Solid core Stranded

To prevent electromagnetic interference, shielded twisted-pair (STP) cables are

recommended. Unlike their unshielded cousins, STP cables have shielding that

reduces noise. Like a balanced analog cable, STP cables have to be grounded,

so you’ll need to use STP-compatible RJ45 or EtherCon connectors.

3 Conﬁguring Your AVB Network

3.1 Using AVB with a StudioLive Series III mixer and a Mac

StudioLive™ Series III

AVB Networking Guide

3Conﬁguring Your AVB Network

3.1 Using AVB with a StudioLive Series III mixer and a Mac

StudioLive Series III mixers allow you to record and playback audio over AVB on any

Mac that supports AVB. A single computer can be used both to control and to record

from the StudioLive, or separate computers can be used for control and audio.

Note: At the time of publication Apple only supports

connecting one computer via AVB.

3.1.1 What You Will Need

•StudioLive Series III mixer

•An AVB-compatible Mac running 10.9.5 or later. Any Mac with a

Thunderbolt connection should provide hardware support for AVB.

Note: At the time of publication, AVB is not functioning in macOS 10.13 High Sierra.

•If your computer does not have a built-in Ethernet port, you will also need a

Thunderbolt-to-Ethernet adapter. USB-to-Ethernet adapters do not support AVB.

Note: Recording over AVB is not supported while using Stagebox mode with your

StudioLive Series III mixer. Connecting a Mac to your AVB network with your StudioLive

mixer enabled as an AVB device will disable Stagebox mode.

3.1.2 Making the Connections

If you would like to remote control the mixer using UC Surface or QMix-UC,

the control port on the back of the mixer must be connected either directly

to a control device or to the same wireless network as the device running the

control software. The easiest conﬁguration is to connect a wireless router to

the mixer’s control port and then connect your computer or other remote

devices to the router using either wired or wireless connections. If you

need AVB audio between more than just the mixer and the one computer,

you can incorporate an AVB switch to create a full AVB network.

Note: StudioLive Series III mixers cannot be remote controlled over the audio

network connection.

MANUFACTURINGDATE

DESIGNEDANDENGINEEREDINBATONROUGE,LA,USA • MANUFACTURED IN CHINA • PATENTS PENDING • “STUDIOLIVE”

and“PreSonus”AREREGISTEREDTRADEMARSKOFPRESONUSAUDIOELECTRONICS • SD LOGO IS A TRADEMARK OF SD-3C, LLC

iPad running UC Surface

Android running QMix-UC

3 Conﬁguring Your AVB Network

3.1 Using AVB with a StudioLive Series III mixer and a Mac

StudioLive™ Series III

AVB Networking Guide

3.1.3 Setting Up Your Mac

1. Open Audio/MIDI Setup.

2. Go to Window>Show Network Devices Browser.

3. Check the box next to“StudioLive 32”to enable the mixer to be

used as a Core Audio device (this may take a moment).

Once your computer has successfully connected to your StudioLive Series III mixer,

your mixer will appear in Audio MIDI Setup as an available audio device that you can

use with any software that supports Core Audio (Studio One, Pro Tools, Logic, etc.).

Integration, and XMAX are trademarks or registered trademarks of PreSonus Audio Electronics, Inc. Capture, Impact, Mixverb Presence, RedLightDist, SampleOne, Studio One, and

Tricomp are trademarks or registered trademarks of PreSonus Software Ltd. Mac and Mac OS are registered trademarks of Apple, Inc., in the U.S. and other countries.Windows is a

registered trademark of Microsoft, Inc., in the U.S. and other countries. Other product names mentioned herein may be trademarks of their respective companies. All speciﬁcations