IP telephony has today become an incontestable reality. In many European cities, it is no longer possible to take the underground without seeing posters advertising ‘even cheaper’ DSL and voice at every station, or to open a newspaper without reading about the numerous economic models being offered by telecommunication operators or the latest acquisition in the VoIP sector. More and more enterprises are deploying IP-PBXs or subscribing to new IP Centrex offers.

Taking all this into consideration, one could be tempted to conclude that the latest problems related to IP Telephony have been resolved and that the technology is now fully mature. But this is far from reality! The more advanced the technology is, the higher the expectations of perfection become so it will still be some time before VoIP becomes a commodity.

On the residential market, the challenges are numerous. First of all, consider unbundling. Is it acceptable that an operator who unbundles leaves you without a telephone or even emergency services for two weeks without informing you beforehand or apologising for the inconvenience (author’s own personal experience)? Is it acceptable that the telephone stops working when the television (also IP-based) is switched on?

Such problems are far from exceptional and reveal the laxness of the regulatory authorities who allow many telephony offers to be presented as alternatives to primary lines when in fact they are unable to come even close to the required characteristics. Much less easy for the consumer to spot, yet evident for those in the business, too many VoIP services lack the statutory requirements and the robustness that are necessary to present an offer as a substitute for a fixed line. These include the possibility for the legal interception of calls, the priority of voice traffic over data, and system security on switches through firewalls or Session Border Controllers to avoid attacks.

The threat of consumer action in France, something demanded for years by consumer associations, would quickly put an end to VoIP offers that deliver adequate services only ’80 per cent of the time’ and, without a doubt, would quickly clean up the VoIP market place. Unfortunately, the trend today is to offer telephony services which work ‘up to 100 per cent of the time’!

Beyond these problems, which result more from the rushed packaging of services rather than from the limitations of the technology itself, a number of technical challenges still remain. For instance, it is essential to interconnect VoIP operators via IP, without passing through the PSTN, in order to avoid echo problems. This is very difficult to achieve in terms of number portability where nothing in the telephone numbering systems indicates if the destination is IP or not. The only way to resolve this problem will almost certainly be the creation of a national portability server where not only administrative but also technical information is registered.

Such direct interconnections would also imply that operators agree on both voice coding systems in order to avoid transcoding where possible, and interoperability profiles of VoIP protocols. In the near future, this kind of interconnection should also work with video calls and with wideband (‘hi-fi’) voice calls. It is likely that companies commercializing Session Border Controllers will, while waiting for an overall agreement on media converters and their protocols, carry out essential profile conversions between VoIP operators.

For companies that already have an IP-PBX, the main problem today is the ability to interconnect with the public network using IP. For the time being, this possibility is reserved for IP Centrex users only. In order to avoid echo problems related to cumulated delays, companies using IP-PBXs should ensure that all communication with IP operators, (for example communication ‘box’ users), is carried out using IP, without converting to classic telephony. Obviously, it is necessary to begin by interconnecting the public network using IP.

A few ‘IP Trunking’ offers are now available on the market and should make such interconnections widely available in the long run. But again, it will be crucial for IP-PBX manufacturers to certify their VoIP protocol layer in order to ensure compatibility with the new public IP network. Operators should therefore create such protocol profiles and ensure their certification. These types of compatibility labels will probably come into force in 2006, and it will be important for companies that acquire an IP-PBX to verify that it has the ‘public IP Network’ label.

Today, manufacturers face a situation where technical standards bodies alone cannot resolve the remaining issues related to VoIP. High network quality, IP portability, guaranteed IP interconnections between operators, protocol certifications: these issues belong mostly to the regulatory authorities, unless VoIP operators manage to put harsh competition aside and agree on such topics without dragging down the quality of VoIP offers. It is often said that regulation curbs innovation and slows down the market.

However, the maturity of today’s VoIP market, which extends to millions of users, generates a need for the regulator to play a key role in making the new, multimedia IP network generally available, without consumers losing the reliability or ubiquity that they have become used to with the public telephony network. It is time we changed from talking about ‘best effort’ and introduce ‘guaranteed quality’.

BIOS, Jan 13, 06 | Print | Send | Comments (0) | Posted In Networking