Evaluating IP Telephony Systems

--David Strom

IP telephony began humbly as a novelty application that allowed online users to converse over the Internet. Today, it has finally matured enough in both feature sets and network availability that it can replace the traditional PBX,the heart of any business telephone system.

IP telephony offers many advantages. Imagine a customer visiting a corporate Web site and requesting more information about a product offering. As soon as this customer submits a Web form, the contact information is verified, the customer's area code is cross-referenced and the appropriate salesperson receives a Web-based alert explaining the customer's interests,all while the salesperson's phone automatically dials the customer. The customer could literally receive a call back faster than it takes to load the next Web page.

However, these systems also have a big drawback: They can stress your customer's enterprise network. The impact goes beyond just taking extra bandwidth. Telephone conversations are far less forgiving to packet loss and network latency. So it's crucial that networks are prepared and tested, with quality of service (QoS) guarantees in place.

VARBusiness asked product testing partner KeyLabs to examine several different products and report on their capabilities. We examined solutions from Avaya, Nortel Networks, Shoreline and 3Com. Cisco and Siemens were also invited, but neither chose to participate. (Read "VARs Rave About Cisco's Avvid" for some interesting VAR experiences with Cisco's gear.)

Overall, we were impressed with the capabilities of each of the four solutions, and we could recommend them all, given the right environment. But of the four products tested, our top choice is Nortel's BCM 400 series because of its flexibility and configuration options. The Nortel BCM is the most feature-rich of the solutions, pulling the majority of its features from Nortel's Norstar systems. It offers a near carrier-grade solution, but this flexibility might overwhelm some integrators.

For this reason, we also give a nod to the Shoreline4 IP telephony system, which demonstrated how close a phone system can come to being called "turnkey." Shoreline has created a good, easy-to-configure package that will amaze most small businesses with its capabilities.

Along with Shoreline4, 3Com's SuperStack 3 NBX V5000 Call Processor product was, hands-down, the easiest to use. Both provide strong GUI applications with intuitive point-and-click navigation and configuration. Shoreline, in particular, is architected in such a way that analog and IP phones can coexist without having to buy extra equipment, and adding new phones is an effortless process. We recommend both of these for SMB organizations because once they are installed, they are easy to administer and don't require extensive telecom experience.

Now, if you're like us and want to be able to tweak, configure and manage every aspect of a system, then Nortel's BCM 400 and Avaya's IP Office provide the most powerful interfaces. They felt similar to some of the TDM switches we've used in the past. Both systems had fairly intuitive interfaces, and the available choices and options are extensive and will give experienced operators powerful ways to fine-tune their systems.

Our Test Network
To get all the IP phone vendors on the same page, we asked them to provide a solution to address four different business environments:

• A company with 25 employees and a 256-Kbps Internet connection.
• A company with 100 employees and a 512-Kbps Internet connection.
• A company with 500 employees and a 1.544-Mbps Internet connection.
• A single company comprised the three previously listed environments.

We also asked the participants to provide support for a PSTN connection; however, we did not benchmark this connectivity.

The test network configuration consisted of two identical networks separated by a WAN simulator. The WAN simulator was configured as a V.35 1.544-Mbps circuit connecting two Cisco switches via serial interfaces. The routers both provided a 10-Mbps connection to a Cisco switch where the IP gateway/PBX architectures plugged in. All routing was static. Our test network remained unchanged down to the cabling for each QoS test. Each IP phone-switching solution was configured to connect an analog desk phone that could dial an extension and ring an analog phone on the other network.

We employed the Empirix Hammer test tool to measure call-quality objectivity, which pro-vides metrics on industry-standard Perceptual Speech Quality Measurement and Perceptual Evaluation of Speech Quality. Once this configuration was verified by placing phone calls from one network to the next, the Empirix Hammer was connected and testing commenced.

What We Found
Each of the four IP products came with a dizzying array of options, features and capabilities, and it was easy to get overwhelmed by everything an IP phone system can do. Features like Microsoft Outlook integration and an XML programming interface can be invaluable options. Still, some of these add-on packages come with hefty price tags, so it's important to list and prioritize needs and wants. Every add-on also increases the complexity of managing the system. Fortunately, all parties involved had very knowledgeable technical support staffs.

3Com provides a great replacement for small PBX systems. Offering an easy-to-use configuration interface, 3Com provided us with a call processor and a gateway chassis, which was used to hold the interface cards. Everything was connected via Ethernet, and the call processors maintained the configuration. With the help of 3Com's support, we had the system up and running well within an hour or two.

Shoreline also provides a great replacement for small PBX systems. Its hardware configuration is a bit different from 3Com's SuperStack. It requires you to have a server set up as a main controller. This is where the entire configuration takes place. Once configured, we could remove and replace

the ShoreGear switches without any further reconfiguration. We experienced this firsthand when one of the eval-uation units had to be replaced by Shoreline. Once the ShoreGear switch arrived, we plugged it in, and it immediately worked.

Avaya IP Office is a great solution for SMB companies that need a small PBX system. The Avaya IP Office seemed to be a bit more difficult to configure, or at least less intuitive. At the same time, it seemed to have a similar feel to a legacy phone system, providing more in-depth configurations, whereas 3Com's SuperStack and Shoreline's products seemed to make it easy for anyone to click a configuration right out of the box. Once Avaya IP Office was configured and running, it, too, could be quickly modified and changed by someone who possesses semitechnical skills.

One last thing about the IP Office: Although SMB companies will make great use of switches, you may also use them as a solution for small call centers. The Avaya MultiVantage and Nortel BCM switches would be overkill for an SMB business, unless it plans on growing quickly. These switches could easily run call centers, factories and warehouses, etc. Like the IP Office, they resemble legacy TDM systems. The configuration methods and options feel endless. Port density is definitely where this equipment shines, allowing organizations to grow without scrapping the phone system.

Network Recommendations
IT managers and those responsible for deploying IP phone systems have a daunting task. After answering some of the more obvious questions (i.e., How many extensions? What features are most needed? How many locations? What does current call traffic look like?), IT managers will soon realize that the single largest postdeployment headache is the network. Since the IP phone system will be running on the data network instead of its own separate copper, it's important to verify the health and integrity of both LAN and WAN connections. Here are a few of the main areas that need to be tested and reviewed.

• Network utilization: Minimum, maximum and average bandwidth utilization, latency and jitter can impact performance and call quality. This should be monitored throughout the business week, as overall utilization tends to be higher at different times and different days. We recommend that solution providers correlate this with daily phone traffic. You will probably discover your clients' busiest IP network times are also their busiest phone network times.
• Networking hardware: Check the VoIP path and make sure the equipment is not being overtaxed. If you have a dynamic environment, do the usual changes affect any of this equipment? Are all the switches touched by the VoIP traffic VLANed? Are the configurations correct, and are all the ports negotiated correctly? One of the most common mistakes our customers make is to switch ports being negotiated at 10 Mb/half duplex when it was thought to have been 100 Mb/full duplex. IP QoS should be supported and configured, and, if possible, ensured that priority is given to these voice packets.
• Establish policies: Is everything redundant,especially border equipment and uplinks? Are bandwidth upgrade metrics established? For example, when the network averages 50 percent utilization for "x" amount of time, we need to order "x" amount more bandwidth. Does failover policy support the tolerance needed by voice traffic?
• Test: There are all kinds of testing equipment and houses that should be used before and after installation of VoIP equipment. It is essential to verify network conditions at each step. Test failover and benchmark voice calls and compression performance during busy network times. If that can't be done during business hours, make sure you can closely model your clients' traffic and be able to point out possible trouble spots in their networks. Also, look closely at your customers' dial plans to make sure they offer the most cost-effective and safe solution.

Keylabs IP PBX Product Info

Company Name: 3Com
Product Name: SuperStack 3 NBX V5000 Call Processor
URL: www.3com.com\ Phone: (408) 326-5000
Price: 25 users,$13,790 ($552/station); 100 users,$48,415 ($484/station); 500 users,$256,180 ($512/station)
Pros: Easy to administrate, intuitive interface and easy to install with auto detection of interfaces.
Cons: The auto-detect feature did not always work. The NBX had a lack of features compared with the other solutions.

Company Name: Avaya
Product Name: IP Office 406/400, MultiVantage
URL: www.avaya.com\ Phone: (866) 462-8292
Price: IP Office Configuration 25 users,$16,124 ($645/station); 100 users,$43,907 ($439/station)
MultiVantage Configuration 25 users,$27,868 ($1,115/station); 100 users,$63,942 ($639/station); 500 users,$332,602 ($665/station)
Pros: Easy-to-use and intuitive CRM applications with a feature-rich package selection.
Cons: Does not have the most intuitive configuration or administrative interface.

Company Name: Nortel Networks
Product Name: BCM 400 and BCM 1000e
URL: www.nortelnetworks.com\ Phone: (905) 863-0000
Price: 25 users,$20,485 ($819/station); 90 users,$58,840 ($654/station)
Pros: Comprehensive feature set that rivals both legacy and IP PBXs of any size.
Cons: Configuration can be overwhelming for inexperienced administrators.

Company Name: Shoreline Communications
Product Name: Shoreline4 IP
Telephony System
URL: www.goshoreline.com\ Phone: (408) 331-3313
Price: 25 users,$19,000 ($760/station); 100 users,$73,000 ($730/station); 500 users,$370,000 ($740/station)
Pros: Easy to administrate and intuitive interface; easy to install both local and distributed environments. Ports support analog, digital and IP phones with no need for different cards. Most features are included with the standard features for the phone or the desktop Call Manager application and are part of the basic pricing.
Cons: Could use a larger feature set. Very tied to Microsoft Outlook.

Ray Bruni ([email protected]), CISSP, is senior security architect at KeyLabs.