The Evolution of Audio over IP

The shift from analog and digital point-to-point audio connections to networked audio has been one of the most significant changes in the pro audio industry over the past decade. Audio over IP (AoIP) systems allow multiple audio channels, control data, and metadata to travel over standard Ethernet networks, reducing cabling complexity and increasing system flexibility. Among the key protocols driving this transformation is Ravenna, an open standard that brings deterministic, low-latency audio transport to a wide range of professional applications. Ravenna was first developed by ALC NetworX, a Munich-based company, and has since been adopted by major manufacturers like Neumann, Riedel, and DirectOut. Its open, royalty-free nature makes it an attractive alternative to proprietary solutions, particularly in environments that require interoperability across different hardware and software ecosystems.

What Is Ravenna?

Ravenna is a real-time audio-over-IP protocol that uses standard Ethernet hardware and can operate on existing network infrastructure. At its core, Ravenna is built on the IEEE 1588 Precision Time Protocol (PTP) for precise clock synchronization across all devices on the network. This enables sample-accurate alignment of audio streams, even when devices are tens of meters apart. Ravenna is fully compliant with the AES67 audio-over-IP interoperability standard, meaning Ravenna devices can communicate directly with devices running other AES67-compliant protocols such as Dante, Livewire, or Q-SYS. Additionally, Ravenna supports the SMPTE ST 2110 suite of standards for professional broadcast media, making it a future-proof choice for IP-based broadcast facilities.

How Ravenna Differs from Other AoIP Protocols

While many AoIP protocols share similar foundations (Ethernet, PTP, RTP), Ravenna’s open architecture and focus on interoperability set it apart. Unlike Dante, which is managed by Audinate as a closed ecosystem requiring licensing, Ravenna is an open standard with published specifications. This openness encourages third‑party development and integration. Another key differentiator is Ravenna’s support for a wide range of audio sample rates and bit depths, including 24‑bit/192kHz and beyond. Additionally, Ravenna can handle both unicast and multicast streams, allowing system designers to balance bandwidth usage and device addressing requirements. The protocol also incorporates redundant network paths (on the same cable or separate cables) to provide failsafe operation in critical applications such as broadcast and live sound.

Key Technical Features of Ravenna

Low Latency and Deterministic Transport

Ravenna achieves round-trip latencies as low as 125 microseconds (1/8th of a millisecond) in optimized configurations. This is accomplished by using a combination of PTP clock synchronization, packet priority marking (DSCP), and efficient stream buffering. For most live sound and monitoring applications, total system latency below 1 millisecond is indistinguishable from a direct analog connection. Ravenna’s deterministic delivery ensures that audio packets arrive within a bounded time window, preventing jitter and dropouts.

High Channel Density and Scalability

Because Ravenna operates on Gigabit Ethernet (and can work with 10GbE and 25GbE), a single network cable can carry hundreds of bidirectional audio channels. For example, a Gigabit Ethernet link can support over 100 channels of 24‑bit/48kHz audio, while 10GbE can scale to thousands of channels. This makes Ravenna suitable for everything from small recording studios to massive broadcast facilities with hundreds of inputs and outputs. The protocol’s multicast capabilities also allow one audio source to feed multiple destinations without increasing network bandwidth linearly.

Interoperability and Open Standards

Ravenna was designed from the beginning to be compatible with AES67, and it is also aligned with the SMPTE ST 2110 standards. This ensures that Ravenna devices can coexist and communicate with equipment from other manufacturers that support these standards. Many broadcast plants are now transitioning to ST 2110, and Ravenna’s compliance means Ravenna-equipped microphones, stage boxes, mixing consoles, and converters can be integrated seamlessly. The open nature of Ravenna also encourages software developers to create control and monitoring applications that can manage Ravenna devices alongside other AoIP gear.

Network Resilience and Redundancy

Ravenna supports several redundancy mechanisms. The most common is Seamless Redundancy (also called RAVENNA over two networks), where two separate Ethernet networks carry identical audio streams. If one network path fails, the receiving device can switch instantly to the other without any audio dropout. Another approach is using Link Aggregation (LAG) or Spanning Tree Protocol (STP) at the switch level. Ravenna’s redundancy features are essential for live broadcast, theatre, and mission-critical PA systems where any audio interruption is unacceptable.

Use Cases and Applications

Live Sound and Touring

In live sound, Ravenna is increasingly used for digital stage boxes, monitor consoles, FOH consoles, and distributed loudspeaker systems. Its low latency makes it feasible to send microphone signals from the stage to the mix position over long distances using standard CAT6 cables instead of heavy multicore copper snakes. Venues that have a permanent Ravenna network infrastructure can support any touring act that brings a Ravenna-compatible console or stage rack. Event production companies also benefit from Ravenna’s ability to connect multiple mixing positions and broadcast trucks using the same network.

Broadcast and Media Production

Broadcasters are moving toward IP-based production studios, and Ravenna plays a major role in this transformation. The protocol can carry not only audio but also control signals, metadata, and timecode over the same network. Ravenna’s compliance with SMPTE ST 2110-30 (audio) and ST 2110-31 (AES3 transport) allows live audio streams to be routed, monitored, and recorded alongside video and data streams in a fully IP environment. Many radio stations, OB vans, and television studios have deployed Ravenna as their core audio backbone, replacing legacy MADI and AES3 connections.

Recording Studios and Post‑Production

In recording studios, Ravenna enables the creation of flexible, expandable systems where microphones, preamps, AD/DA converters, and monitoring controllers are connected via a single Ethernet network. Engineers can patch any source to any destination without moving cables, and the network can be extended to remote rooms or even to a separate machine room. Post‑production houses use Ravenna to move multi‑channel audio between editing suites, dubbing stages, and mixing rooms with sample‑accurate sync. Software‑based DAWs such as Steinberg Nuendo and Cubase include native support for Ravenna, making it straightforward to integrate hardware converters.

Installed Sound and Corporate AV

For installed sound systems in conference centers, houses of worship, and performing arts venues, Ravenna offers a cost‑effective way to distribute audio across large areas. By using off‑the‑shelf managed switches, installers can create a single network that handles both audio and control data. Ravenna’s support for multicast makes it efficient to send the same feed to many zones, while its ability to carry redundant streams ensures reliability during critical presentations or ceremonies.

Network Requirements and Best Practices

Although Ravenna is designed to work on standard Ethernet networks, certain requirements must be met for reliable operation. All switches must support IGMP snooping (for multicast filtering), DiffServ (DSCP) for packet priority, and IEEE 1588 PTP for synchronization. The network should be built with managed Gigabit (or faster) switches, and the topology should avoid excessive hops to keep latency low. For larger networks, a dedicated VLAN for audio data is recommended to isolate traffic from office or internet traffic. Additionally, the use of a dedicated PTP grandmaster clock (either a hardware device or a software‑based solution) helps maintain stable synchronization across all devices. ALC NetworX provides detailed network design guides that cover these topics in depth.

Comparing Ravenna with Other AoIP Protocols

Networked audio professionals often compare Ravenna to other leading protocols. The most common alternatives include Dante (Audinate), AVB (IEEE 802.1BA), and Livewire (Telos). Here is a summary of the key differences:

  • Dante: Proprietary but widely adopted. Easier to set up in smaller systems; requires licensing fees. Limited native support for sample rates above 192kHz and for ST 2110.
  • AVB (Audio Video Bridging): IEEE standard with built-in bandwidth reservation and latency guarantees. Requires AVB-enabled switches, which are less common and more expensive. Smaller ecosystem compared to Ravenna.
  • Livewire: Very popular in radio broadcast; comes with specific AoIP hardware from Telos. Interoperable with AES67 but historically closed.
  • Ravenna: Open, high-channel count, supports very high sample rates, native ST 2110, and has a strong presence in both broadcast and live sound. Requires careful network configuration but offers maximum flexibility.

Ultimately, the best choice depends on the scale, existing gear, and future roadmap of the facility. Many large‑scale broadcast installations now select Ravenna because of its open‑standards base and compatibility with ST 2110.

Future of Ravenna and Networked Audio

As the industry moves toward fully networked workflows, Ravenna is expected to evolve alongside new network technologies and standards. ALC NetworX is a key contributor to the Audio Engineering Society’s standards on AoIP, and Ravenna is already incorporating features like high‑channel‑count transport for immersive audio (Dolby Atmos, Auro‑3D) and integration with newer network speeds such as 25GbE and 100GbE. The ongoing adoption of SMPTE ST 2110 in broadcast ensures that Ravenna will remain a vital component of IP‑based media infrastructures for years to come. Additionally, the emergence of software‑defined audio ecosystems and cloud‑based production may see Ravenna adapted for use over wide‑area networks and virtualized environments.

Conclusion

Ravenna is not just another audio networking protocol; it is a comprehensive, open infrastructure designed for the most demanding professional applications. Its ability to deliver ultra‑low latency, high channel counts, and robust interoperability across multiple standards makes it a strong choice for anyone building or upgrading a networked audio system. By leveraging standard Ethernet and open protocols, Ravenna future‑proofs investments and simplifies system integration. Whether you work in live sound, broadcast, recording, or installed sound, understanding Ravenna’s role is essential for making informed decisions about networked audio infrastructure. For more detailed technical information, refer to the official Ravenna website and the AES67 specification.