Technologies come and go. Some are resilient to the test of time. Others experience a brief rise in the light of analyst's stock upgrades and then fall by the wayside. In this text, we are going to look at IP phones. I'll give you the rundown of these devices, a list of the market players, and my own opinions on the technology. Hopefully, I'll impart enough knowledge so that you can make your own opinions.

IP Phones are private branch exchange (PBX or phone system) accessories. They are like their name suggests, phone sets. However, instead of connecting to your phone system with a dedicated Category 3 cable, they run over your IP-based network. I first heard about this technology three years ago. As my main focus is networking, I was excited! "Could you imagine just plugging your phone into the network, having it find your phone system, and there you go?"

The primary technology behind IP phones is Voice over IP (VOIP). VOIP takes an analog signal such as your voice, compresses it into a digital signal, sends it over a medium, and then decompresses it on the other end. The encoding and decoding process can use many different standards, including H.323, G.711, G.723.1, and G.729A. These protocols are typically referred to as codecs (compressor/decompressor).

The purpose of a codec is to compress input as much as possible and send a steady flow of data over a link. For a technology like IP phones, this means that you have Toll-Based Quality, the quality that you are used to receiving over a standard phone. In the early days of codecs, processors were significantly slower and could not perform compression and decompression quickly, so either Toll-Based Quality or great amounts of bandwidth had to be sacrificed.

At present, the quality of the VOIP that I have seen has been excellent. Processors are faster, and the technology has hit the ceiling in terms of how much you can compress a signal. Our current IP phone implementation provides quality that is indistinguishable from any of our other phone sets.

An IP phone system requires two components. The first is, of course, the actual phones. These come in two flavors, a physical phone and a software-based phone. Both provide the same functionality; however, a software-based phone is installed on your computer and uses your existing network connection to communicate with the PBX.

The second component is the card(s) that you install in your phone system to provide a connection to the network and accept sessions from your IP phones. This is probably the most expensive component, as licensing is required for each of the phones you connect to this card.

The Players

Let's look at who some of the players are and how they brand their offerings. Although I haven't configured every one of these systems, I can tell you what each company brings to the table. This is often just as important as the functionality of the product itself.

There is an abundance of companies providing convergence of voice and data, but in this article, I'll review just the four primary ones.

Nortel

Nortel seems to be the brand most recognized in the phone system arena. While their product range has diversified over the years, they still build excellent phone systems. Their latest offering is the Integrated Telephony Gateway (ITG) Line Side Card. Nortel offers both types of phones and, based on my firsthand experience, fits neatly into the network.

Cisco

By far, Cisco's products handle TCP/IP traffic better than anyone else's. That's why I believe that Cisco's Unity platform is the best network performer. Their product range and VAR network are substantial. They also provide both physical and software-based phones. Cisco builds in an Ethernet repeater so that you can connect your PC to your phone and only consume one network port.

3Com

3Com's strength in this market is more exposure and experience with end users. Their drivers for peripherals are easy to use, and their plug-and-play works. Factor in their Superstack NBX phone system solution, and you can expect their administration and implementation to be simpler than with other offerings. It was their offering that I first heard of, and I believe them to be more flexible to market conditions and demands. While 3COM isn't considered a phone system provider, their network products are excellent and a joy to work with, and I believe this will hold true with their NBX offering.

Mitel

When considering a new technology such as IP phones, the first task is to check a company's Web site for their offerings. Mitel is a popular phone system equipment provider, and doing research on their offerings is a dream. Mitel, based upon their Web site, has an excellent portfolio of offerings. Their current branding is the Integrated Communications Platform (ICP), which touches almost everything they do. Mitel is not as big as the other companies, but they stick to their core competency, which is VOIP.

All of these companies have strengths in different areas. Not one is the best at everything. My advice is to evaluate what you value the most and go with the company that provides it. After my initial investigations, I was given the mandate that I could buy anything, but it better have a Nortel sticker on it! If this happens to you, don't tell your sales rep! Use the knowledge of what other companies provide to get a better price or more equipment.

Sales Pitches

After you have reviewed the market providers, the next step is to deal with the sales people. You will hear many different pitches. Some are valid; some have no basis in reality. Let's examine some of those pitches and determine how important they may or may not be to you.

Save Money by Unifying on a Single Wiring Standard

This is the most popular sales pitch that you may hear if you're planning to unify on a single network. If you are opening a new facility, this may be important to you. In reality, you would typically have an existing phone cabling infrastructure, which your budget has already accommodated. Also, Category 5 cabling is more expensive to implement than Category 3 and is less forgiving to imperfections.

Our Category 5 network has ceiling support every five feet, contains expensive punch-down panels, and has gone through rigorous testing and certification. By comparison, the Category 3 phone cabling that we used for our new phone system (that I inherited not implemented) was strung every which way, had poor receptacles, and was generally a mass of 10-year-old spaghetti. But it worked--even with the new phone system. For me to replace that cabling even just with new Category 3 would have cost around $20,000 (USD).

The sales pitch is that new IP phones have a built-in Ethernet repeater and will not consume any new ports or cabling. I prefer redundancy and separation in the event of a failure.

Dynamic Configuration and IP Addressing

This is actually a nice feature. When you plug your IP phone into the network, it will get an IP address from a DHCP server, and some phones will download their configuration from the phone system. The actual initial installation is less complex because you do not have to physically connect your phone to the phone system. You still have to identify the phone through a unique identifier and assign buttons, an extension, and a Direct Inward Dial (DID) number if different from your extension. You also have to initialize the voice mailbox. However, most of these steps can be performed in advance, and the phone will be up and running shortly after plugging it into the network.

Simplified Administration

Because your phones are IP-based, your administration will be too--of course, through a Web browser. What could be easier?

This is a nice feature, but it's not intrinsic to an IP phone. Phone system service providers have always had a nice, tight wrap of moves, adds, and deletes, as the command prompt interface was cryptic at best. With new browser-based administration features and the ease of IP phones, you can now take control of your phone system and save on outsourcing. And if you're a geek like me, it will actually be interesting to learn a new technology.

The gotcha with this is that simplified administration is not a direct result of having IP phones. It's a result of having IP phones and it being taboo to not have a Web browser configuration interface. Companies that have been around for a long time, like Nortel, could have provided browser interfaces three or more years ago. The problem is that their VAR network would have revolted at the loss in service revenue, which has higher margins than equipment sales.

Unified Messaging

Unified messaging provides features like having your voicemail messages and faxes appear in your email inbox. This is a great feature, but it's not a result of IP phones themselves, as they do not perform this unification. All the logic is in the phone system itself and is available for fixed-cable phone sets.

Sales people will push heavily for these types of features, as they are software-based. The margins are phenomenal for this software, as it is typically installed out of the box with the phone system and all you need is a key code. If you are interested in this, negotiate a price drop, as the profit margin is high.

Lower Total Cost of Ownership (TCO)

Once a phone is set up, forget about it. What could go wrong? With the previous generation of phones, this was true. But what about IP phones? When there is a failure you have to check DCHP, TCP/IP, routing, network cabling, network congestion, prioritization, and any network-specific issues you see in your environment.

A wired phone is directly connected to the phone system with two or more wires. If there is a problem, you either swap the set or check the cabling, using a tone generator. It is this type of simplicity that keeps the TCO down.

Hidden Costs

Speaking of TCO, you have to consider the hidden costs that are part of the initial procurement as well as those that you may see down the road. If you've already spent the money for all the amenities, the transition is less painful. If not, then break out the wallet.

The most critical component to IP phones is Layer 3 switching in your Ethernet network. IP phones demand excellent response to the network. Imagine having your V.P. of Sales on a conference call with your customers and there is a quarter-second delay on the other end. This is a possibility if your network is not geared for handling an IP phone, which requires constant bandwidth and very little network latency.

Layer 3 switches allow for prioritization for certain network services across the entire network. Layer 2 switches allow you to prioritize a particular IP address, network interface card address, or port on the switch. The innovation in Layer 3 is that the switch will see that it is voice traffic and give it priority over services such as Web browsing or email, no matter its source or destination.

Layer 3 switches are becoming more popular partially as a result of voice and data convergence. The cost per port is dropping and becoming more affordable. Of course, most of the vendors I mentioned have their own Layer 3 offering that they are more than willing to sell you.

Depending on the features of the phone sets that you provide to your users, I think you'll see that IP-based phone sets are more expensive than traditional phone sets. This stems from more expensive components and more logic in the phone.

One other hidden cost is that you will need to add quite a few additional ports on your Ethernet infrastructure if you are paranoid like me and want everything to have its own port to remove points of failure. This can be costly both initially and down the road if your company is growing.

True Benefits

Historically, IP phones have been a pretty grim proposition, but all is not bad. Let's review IP phones' good points.

In some organizations, sales personnel do not have dedicated offices or cubicles. Wherever they sit at any time is where their area is. They need to have access to a phone and voicemail. With an IP phone (either a physical phone or a software-based phone), their extension follows them when they plug in--even across different locations if you have a WAN infrastructure in place.

Executives and employees who occasionally or regularly work from home could also access the corporate phone system. I have children, and of course they get sick. If I stay home to take care of them, I have to submit expense reports for long-distance calls placed, and I am less accessible to the local user community. With an IP phone, I could receive support calls at home and place calls without having to submit an expense report. My users would be serviced better because they would be oblivious to the fact that I am not sitting in my office.
With this type of service, you must have a virtual private network (VPN) infrastructure as well as a solid, fast Internet connection. I've tried this with a physical IP phone with mixed results. I have a high-speed cable connection with Windows 2000 providing Internet Connection Sharing and Dial on Demand routing through a VPN to my office. I've set up the IP phone to use this VPN service so that I can place phone calls. Currently, I can speak to the person on the other end, but I cannot hear! However, this is not a problem with the IP phone; it's the configuration of my VPN--soon to be resolved.

The new software-based IP phones are designed with this feature in mind. Users who have a high-speed Internet connection at home can simply start the VPN and then start the software phone application; they are then operating on the corporate phone system.

One more benefit is that implementation is simple in a campus-type building where you do not want to build an IT infrastructure and phone system. With a T1 line and prioritization, you can host all PBX activities from a central location and deploy only IP phones. You simply invest in Category 5 cabling and preconfigure the phones before deployment; you do not have to place a phone system in the campus location. This is one area where you can lower your TCO.

Wrap Up

IP phones are a good technology for certain situations. However, there are some added costs, and implementation can be complicated. Depending on your circumstances, IP phones may be the next generation or just another wayside candidate.

Chris Green is a Senior Network Support Specialist located in Toronto, Ontario, Canada. He has seven years experience focusing on the iSeries 400 and networking technologies. Utilizing this experience, he has authored over 30 articles and several white papers and has co-authored an IBM Redbook.

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