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Is Voice Over IP Ready?

We may be ready for Voice over IP -- in all its varieties -- but is it ready for us?


May 1, 2002  


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Implementation of Voice over IP (VoIP) telephony is a growing trend that is expected to be a multi-billion dollar industry in the next five years.

And while that is all fine and good, I think we really have to ask ourselves: “Is VoIP — particularly in the LAN — really ready for “prime time?” I personally think it still has a fair way to go.

THREE DIFFERENT FLAVOURS

VoIP telephony comes in three flavours: it can be implemented over the Internet, between branch offices over a corporate Wide Area Network (WAN), or over the Local Area Network (LAN).

VoIP over the Internet has been an exciting way for users to talk to friends anywhere in the world for a low monthly Internet connection charge. While this type of implementation does work, it can be choppy during times of congestion, as “bursty” traffic can cause data packets containing voice to be delayed or lost. Yet, many users are willing to tolerate this level of service, as the service itself is essentially free.

A WORD ON THE WAN

VoIP in the WAN is a new evolution and allows corporations to share bandwidth and reduce monthly operating costs. Today, we have the ability to convert voice into IP packets, and voice and data can now share the same T1 or T3 connection.

Although the concept of “converging” voice and data traffic is a good one, we must be cautious. It is important to understand that voice is a real-time application. Each and every packet must get through on time, the first time. While data applications have the built-in ability to request the re-transmission of a packet if it does not arrive or is corrupt, voice applications do not. Instead, the voice error correction consists of users asking: “Can you say that again?”

Just look at the difference between the quality of a cell phone conversation and a land line conversation. Don’t get me wrong, cell phone networks have come a long way and we all know where the “dead” spots are, but we are willing to make a trade-off between these dead zones and convenience. The same goes for mixing voice and data traffic: Though VoIP prioritizes voice packets over data, things happen in the world of electronics during times of congestion.

Most traditional telecommunications manufacturers have products available that interface their equipment to an IP connection. The ideal implementation is one in which if the IP connection becomes congested, the equipment is able to automatically re-route the call over to the traditional Public Switch Telephone Network (PSTN) until the congestion either dissipates or the call is terminated. I like this technology and think it is ready.

THE LAY OF THE LAN

VoIP in the LAN is still a big concern for me. Most traditional voice manufacturers have a strategy of inserting IP cards into their systems and offer a blended environment. Some even have total IP solutions that worry me with potential security/crash problems. (We all know the joys we experience when we see the “blue screen of death”).

I must admit that the idea of being able to unplug my phone and move to another desk and have my programming follow me is a cool one. But I must point out that some traditional voice vendors allow users to move from one phone to another and simply log in with a password. VoIP sets do require a separate power source, which should have uninterruptible power.

Speaking of power and VoIP, both TIA and IEEE are reviewing the impacts of in-line power on data transmission in the same 4-pair cable. It looks as though the way the in-line power is generated and the quality of the cable plant will have a direct impact on the quality of voice and data packet transmission. But the jury is still out and we will have to wait and see if any new transmission parameters are specified.

POTENTIAL PROBLEMS

My biggest issue with VoIP is not the technology itself but how it will change the structure of the technology groups that must support it. Voice is an application, and networking departments are not used to application support.

IT departments have separate application development and support groups from networking. It takes a different skill set to be able to sit with users and solve their problems with technology.

Networking groups are typically charged with ensuring the WAN and LAN are up and running in order to support corporate applications. And while the networking people think that since voice is changing to IP it should become their domain, I think it is the voice people who must remain front and centre. They know their respective users, and they can speak their language as well as the language of the telcos.

I think there is room for both groups here and there need not be a turf war. All groups will have to get along in order for this new and promising technology to flourish.

Mark Maloney, RCDD, is a Senior Consultant at Ehvert Technology Services in Toronto and a member of Cabling Systems’ Editorial Advisory Board.


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