This article originally appeared in the Sept. 2010 issue of INTERNET TELEPHONY

In this ever-evolving industry, VoIP peering has gone from non-existence and then existence, but complete obscurity to understood and applied, but not widely publicized. All of that is now changing with not only the introduction, but also the expansion of session border controllers for the enterprise.

These SBCs are special because of their feature set catering to business users with high-class needs, but no engineering staff on hand to work full time on the issues. In addition, they mark a turning point in the positioning of VoIP peering from being a carrier-implemented function to something geared toward the enterprise itself.

Leading the way with this new direction is AudioCodes (News - Alert). As a recent announcement stated the company is, “Addressing the demand for integrated security and connectivity for SIP trunking services for small, medium and large enterprises”. This is quite a statement. It projects that there is in fact demand for SIP trunking across all business sizes and, more importantly, they are all becoming VoIP peering-enabled. As this happens the inevitable is set in motion – enterprise VoIP peering.

These SBCs help to resolve many of the issues that plague all implementations, but none being more difficult to overcome than establishing a standard. Through AudioCodes’ success it will, in essence, be creating its own distributed VoIP peering platform. If an enterprise can establish a SIP trunk to a VoIP carrier, then why couldn’t it do the same with another enterprise?

Although it all sounds glorious, SIP trunking can become very tedious when one network operator must deal with a dozen or more other networks. There are not really many people with the dedicated function of VoIP peering coordinator within an enterprise, but these people do exist on a full-time basis within carriers. Their overhead can be sustained since carriers are in the business of making money from the network. In an enterprise, no matter how vital communications systems are, they are an expense.

Haim Melamed, director of corporate and channel marketing at AudioCodes, had this to say about VoIP peering and AudioCodes’ enterprise offering: “AudioCodes sees VoIP peering as an important trend in the VoIP space, allowing more efficient and cost-effective communications. Our media gateways, multi-service business gateways and enterprise session controllers support the easy configuration of connections to multiple PSTN as well as SIP trunking providers, as well as direct VoIP peering between enterprises. The new E-SBC line makes it easier to securely and transparently connect to anybody you want to peer with.

As SIP trunking becomes more and more popular within enterprises worldwide, VoIP peering is also becoming a real option.”??On the other hand, the flat and/or very low tariffs of national, and in some cases international, calls via PSTN and SIP trunking service providers make the efforts of configuring and securing direct VoIP peering between enterprises redundant for many IT managers. ??

One must remember that direct VoIP peering between enterprises cannot scale to connect to everybody. It is a viable solution for connecting to other enterprises that are connected to your business. When the call volume is very high, and the business relationship is very close, one can benefit from direct VoIP peering. In all other cases, enterprises tend to use the service providers for their calls.??A good example of a very successful VoIP peering environment is Microsoft (News - Alert) OCS. With Microsoft OCS it is very easy to peer (federate) with other enterprises. AudioCodes products enable something very similar.

How, then, do the enterprise users take full advantage of SIP trunking capabilities for VoIP peering on a multi-lateral basis? In the same way the carriers do today – through an ENUM registry.

The ENUM registry is a central repository of the endpoint identifiers, in this case transposed telephone numbers that look like IP addresses, and it allows for the look-up of an endpoint for the establishment of a SIP session. There are a few very well- known ENUM registries in the world, and they are well served by the advances made by companies such as AudioCodes, as the two components almost function optimally as one on a certain level. This seems to be a missing piece of the puzzle. The piece exists; it just does not seem to be in this particular box.

Perhaps AudioCodes should make its enterprise users aware of ENUM and ENUM registries so as to facilitate their peering with each other. Maybe AudioCodes should introduce its enterprise customers to each other through its own hosted ENUM registry. It could be a sort of enterprise social network that allows businesses to link with each other if they have a cause to do so – reducing the phone bill. That would probably drive an even greater adoption rate and accelerate the evolutionary process of TDM to IP for voice.