AUDIO OVER INTERNET PROTOCOL

AUDIO OVER INTERNET PROTOCOL

What makes IP so compelling? It’s “just a protocol,” right? Yes. But a protocol in the data networking context can provide tremendous value to users. At the technology level, it’s simply a set of rules: the way data is assembled into packets, how confirmation of reception is communicated, etc. But to users, it means that any conforming equipment is interoperable. And because the IP protocol was designed with generality and extensibility in mint, it enables designers to create novel applications.

Although originally developed to be used for email and file transfers, as the speed of the internet increased, IP came to be used for media transmissionas well, which is now well known as streaming media. This development has fundamentally altered the nature of how people use the internet, and has subsequently had significant impact on all aspects of media industry as it struggles to cope with the changes it brings and to take advantage of the new opportunities it engenders. Though the internet’s inventors were probably not thinking of streaming when they designed IP, they were thinking that keeping the core open and layered would unlock the door to a variety of applications that future creative types might dream up.

Which bring us to AoIP. While they are related, AoIP is not streaming media. Streaming is exemplifiedpublic Internet application such as YouTube and Pandora. There are no delivery guarantees for these services, and delay can range into tens of seconds.

On the other hand, AoIP is intended to be run exclusively on a controlled local network infrastructure. In some cases, this is just an Ethernet switch. In others, it’s a sophisticated system comprised of multiple to ensure reliable, low-delay delivery of streams suitable for professional applications.

1. Scalability

Perhaps the most fundamental advantage of AoIP systems over other audio technologies-analog or digital-is the ability of its underling IP and Ethernet architectures to adapt to change and growth.

For example, a traditional audio environment must have its spatial  or imaging for-mat (e.g., mono, stereo, or surround) predetermined, along with the number of simultaneous audio channels it requires (e.g., one, two, or more). An AoIP environ-mend has no such requirement, and can easily adapt to any audio channelization for-mat. This applies to accommodation of any other “layer” in the system as well, such as control-data channel. In traditional architectures, a dedicated path had to be specified for these extra channels (such as RS-422 control data). AoIP systems allow such auxiliary components to be easily carried alongside the audio payload.

Similarly, a traditional “cross point” audio routing switcher must have its input and output (I/O) configuration fixed in its hardware design. In this way, such a device reflects circuit switchingand parallel design, whereas AoIP systems implement packed switching and serial design. The packetized, serial approach allows great flexibility and responsivenessin accommodating changes in I/O configuration.

Just as telecoms have moved away from the circuit-switched paths of their earlier year for similar reasons, studio audio systems can now enjoy the same advantages of scalability and flexibility to implement expansion in any dimension. This comes not a moment too soon; given the competitive p reassures coming to bear on broad-casters to accommodate increased content production and expanded audience choice.

2. Cost Effectiveness

At almost any reasonable size, an IP-based audio system will compare favorably with the cost of a tradition system-both in terms of its hardware and materials pricing and its installation costs. The reduction in wire alone provides substantial economy. Maintenance expenses forAoIP systems are generally also lower.

These cost differentials increase with the size of the facility, which is why so many larger installations haves already moved to IP-based solutions as their needs have called for new technical plants.

3. Convenience

The small physical footprint, low operating cost, ease of reconfiguration or upgrade, and fast installations of AoIP systems make them extremely convenient for engineering and operations alike at the audio facility.

From initial design to implementation to daily operation, IP-based systems make life easier.

4. Smooth integration with other IP-Based Systems

VoIP phone systems and IP codecs can be tightly interconnected, creating numerous benefits with regard to both ease of in stallion and feature enhancement.

5. Talking the PC’s Native Language

A lot of studio audio these days is either being sourced from a PC or being sent to one. IP/Ethernet is the PC’s native language, allowing a powerful low-cost interface. Via a single RJ-45 connector. Control comes along for the ride.

6. In the Tech Mainstream

Being in the tech mainstream means that there are a wide variety of learning resources. Book, web sites, and college courses that cover IP and network engineer-in abound.

Category (cat) cables, assembly, assembly tools, RJ patch cords, jacks, testers, etc. Are widely and locally available. Even some Ethernet switches and IP routers are often stocked locally.

7. Future-proofing

Nothing strikes fear in the heart of the engineer or manager more than making a bad decision on a big-ticket purchase. Moving to an IP-based audio architecture takes a lot of the pressure off, since it offers such flexibility and allows broad ability for reconfiguration down the road. Provisioning for unforeseen changes is much less problematic and cheaper with AoIP than with any predecessor architectures.

Note that the above advantages only fully apply to systems that use standard IP in their design. Not all audio systems that use computer networking (over Ethernet and/or on RJ-45 connectors) for interconnection are necessarily “true” AoIP systems. Some systems simply use Ethernet as a physical layer with a proprietary data format above it (e.g., cobra net), while others may use more IP-like formats but with non-standard protocol variations.

Some of these nonstandard approaches may have offered some value in the past (such as reduced overhead and latency over standard IP networking), but give the capacity, speed, and performance of a properly configured, standard IP systems today, the penalties paid by working in a nonstandard environment generally far outweigh any advantages that such variations might provide, particularly when considered over the long term.

CONCLUSION

As the work transitions almost everything to IP, we will likely discover even greater synergies as time goes on. The leveraging of IP as a mechanism to use generalizedsystems and transport paths for various specific tasks has also finding favor in a wide range of other industries systems including the new mobile variants are also favoring an IP distribution model.

For broadcast-industry engineers, familiarity with digital networking technologies, including IP, has become a near requirement of the job anyway (e.g., it’s needed in implementing the online services of a radio station), so why not apply this knowledge to studio audio, too?

It’s becoming clear that IP is truly the way of the digital media world, particularly for an industry that values connectedness, agility, and colt effectiveness. In the radio environment to say that AoIP is the future of studio audio signal flow. Arguing otherwise is difficult: There is and will continue to be so much development within the IP environment that it only makes sense to harness the power of that effort, while also allowing Moore’s law to have its ongoing effect on hardware cost reduction. The effects of these very forces are being enjoyed by so many other industries today; why not in professional as well?