Voice over IP

VoIP has become a mature product. Configurations to support VoIP are standard. Vendors are now able to distinguish the VoIP traffic from normal data traffic with MPLS and provide the high priority service it requires. It simplifies and saves costs for moves. Although VoIP can be a cost effective solution when implementing a new site, or if you need to replace an end-of-life PBX system, it may not always be the most cost-effective solution.

The answer to questions regarding the feasibility of migrating to VoIP services from traditional telephony services is, it depends. You need to understand your current costs. Capture your monthly phone charges, long distance charges, including costs for on-network and off-network, plus the costs for additions, moves, and deletions. For larger companies where it may be a difficult task assembling all the costs, pick a number of locations to represent the typical locations within your organization. This will give you a representative cost structure that you can apply with some accuracy over the remaining locations.

Review various options for implementing VoIP systems. The options range from doing everything yourself to having the voice and data network portions fully managed (as shown in Figure 1). Of course, there are numerous options between these two.

 
Figure 1: VoIP options

If you have capable staff that could easily pick up the technical skills needed, implementing and managing VoIP yourself may be the best option. If skilled staff is missing or workloads prevent picking up the additional responsibility, a partially or fully managed system may be the best option. Vendors will often propose one option, typically a fully managed system, as that is more profitable for them. However, they should be willing to tailor a system for a partially managed solution if you desire. Discuss various alternatives with them so you fully understand all your options and the associated costs and benefits.

To help determine your planned solution, build a VoIP business case. Ideally, the costs associated with converting to your VoIP solution, including on-going costs, are low enough to justify replacing the legacy voice system without any other factors. Many times this is not the case and you will need to consider other cost savings factors that are possible with VoIP solutions. VoIP cost savings include:

§  Elimination of conference call costs

§  Productivity improvements by combining voice mail with e-mail, plus implementing other unified communications services which eliminate the need for people to leave multiple messages when contacting staff for priority action items

§  Improvements in business services where some companies find they can reduce staffing requirements while improving customer service by implementing new telephony applications

§  Simplified technology that supports the infrastructure needed for staff to work at home, which has several cost savings such as higher productivity and reduced office space needs

§  Minimal cabling requirements for new implementations as you run voice and data over the same cable

For business cost analysis, be sure to include all VoIP costs. Some are not necessarily apparent at the beginning of the effort and can substantially reduce savings. Be sure that you do not end up with a VoIP solution that costs more than the current legacy system. Some VoIP costs include:

§  Data network upgrade costs. The data network may require upgrades to support voice traffic. These costs can include hardware replacement and software upgrades. Also, make sure to include costs to support network bandwidth increases needed to support voice traffic.

§  Training costs. You will need to train voice staff on how to configure voice options with a VoIP system. You will need to train network staff to configure network equipment to support voice traffic, and you will need to train support staff to debug problems encountered with the VoIP service. You may be able to reduce training costs with a fully managed VoIP service, but you should still have some trained staff to manage the vendor.

§  Security. You will need to address security concerns on a continuous basis with a VoIP system. Security concerns are virtually non-existent in a legacy telephony system, but you now have to consider security as many viruses can now attack IP phone systems.

§  Hidden fees. Providers can charge hidden fees. While vendors may not always mention these fees in the discovery phase, these charges can show up on the invoices.

§  Merging services. Tying the data and voice network services together can have some operational impact. Data network upgrades or outages can now affect voice services. Business units that were accustomed to using phones as a backup when data network services were not available will find themselves without phone service.

Implementing VoIP systems provide long-term cost savings at best. It can require a substantial cost investment for a do-it-yourself approach. The payback may be multiple years out so make sure the company is ready for this type of investment. Although a fully managed system may save money given the costs of change, it may not be a high priority item for meeting overall cost reduction goals.

Voice-over-IP: Premises Equipment

Voice-over-IP (VoIP) has two components: (1) premises equipment, such as IP telephones and switches, and (2) wide area network facilities and equipment, such as gateways and VoIP cards in routers. Popular publications sometimes confuse the subject by not distinguishing between the two. In some cases, an IP-based PBX is cost-effective when VoIP over a wide area network is not, and vice versa.

A premises-based IP PBX has the following advantages over the traditional, proprietary PBX:

• There is the potential to use a single wiring network for both data and voice rather than separate, parallel wiring systems now used.

• Ease of move, add, change (MAC) within a building. Instead of extensive administrative changes via a proprietary interface, the user's telephone is simply moved from one office to another. Because each telephone set has its own IP address, it rings at the right place as long as it is on the organization's IP network. Some organizations spend thousands of dollars a month on moves within a single building.

• Newer applications, such as unified messaging, are easier to implement on IP-based systems.

• Capacity can be added in much smaller increments than with traditional PBXs, which may require a new shelf, node, or even a complete forklift upgrade.

• IP-based PBXs are generally more open and standards based, holding out the promise of less costly hardware and software enhancements.

• Web-based applications can be easily linked with the IP telephony world. For example, it is far less expensive to install "screen pops" in an IP telephony environment than in traditional PBX systems. Sales personnel and others who need information on the caller can benefit from such features. Another example: an employee has a question about a 401K feature. He finds the information in the organization's intranet Web page. He clicks on a "click to talk" button and the appropriate party is dialed as he picks up his telephone to talk.

Despite these advantages, the IP PBX has a few limitations (at least for the moment):

• IP PBXs have not yet scaled to thousands of users. Nonetheless, each year the number of ports available on a single unit (such as the 3COM NBX 100) continues to increase.

• The "tank-like" reliability of traditional vendors such as Avaya, Nortel, and Siemens has not been achieved — at least in public perception. Like PCs in the early days of the mainframe world, IP PBXs have to evolve bullet-proof armor before Fortune 500 firms will trust their corporate headquarters' voice system to a new technology.

• The huge installed base of legacy, proprietary PBX software will need to be ported or developed for the IP world. That process is occurring rapidly.

• Organizations with unreliable wiring or whose current bandwidth is nearly occluded with data communications traffic (e.g., large file transfers) may not have the building infrastructure to support voice over data.

Exhibit 1 displays a simplified diagram of an IP-based PBX. Note that multiple links are enabled — traditional circuit switched (TDM) telephony, IP telephony via the LAN, and links to the Internet.

Exhibit 1: Example IP (LAN)-Based Telephone System (Courtesy of AltiGen Communications.)

Although it is difficult to quantify the net economic effect, some of the features provided by LAN telephony contribute to greater employee productivity. Many of these features are available in traditional TDM telephony systems, but at a higher cost. Examples include:

• Easy screen pops. When a customer calls, a link is established between the incoming caller ID and a contact package such as ACT!, Outlook, or Goldmine. Information from the contact database is displayed immediately as the call comes in.

• Call handling. When an employee is on the line and another call comes in, a graphical interface simplifies decision making: the call can be ignored, accepted, routed to a queue for others to handle, sent to voicemail, or added to a conference. The key difference from past systems is that these features not only exist on less expensive platforms but they are often displayed on a workstation screen. Hence, employees can actually use the features on the system because the interface is simpler.

• Simplified voicemail/unified messaging. Users can use their workstation interface to listen, save, skip, delete, and scroll through voicemail messages. Clicking on a stored message can return calls. For those so inclined, messages can be saved as an Internet standard WAV file or more compressed proprietary file and forwarded as an e-mail attachment.

To further illustrate some of the capabilities and benefits of IP-based telephony, we can use the Siemens' optiPoint 100 advance IP telephone (ww.siemens.com) as a representative model. Siemens states that optiPoint provides for the following features and benefits:

• Features:

  • Hands-free and speakerphone

  • Memory dial and redial

  • Display of the incoming number (CLI)

  • Call hold/consultation

  • Alternate

  • Call forwarding (CFU, CFB, CFNR)

  • Call waiting

  • Call transfer

  • Call deflection (user-controlled forward)

  • CTI interface allowing TAPI client control

  • Programmable ring tone, volume, and cadence

  • Country-specific menu guidance

• Benefits:

  • Long-distance and toll calls can be transmitted over the IP network, reducing communication costs.

  • Integrating voice and data into one network means investment in one technology and one support organization, reducing infrastructure costs.

  • Software updates and feature enhancements can be downloaded quickly and easily, thus enabling cost-effective upgrades.

  • Intuitive, interactive menu keys and displays along with simple dialing capabilities save time.

  • Direct-dial keys are programmable, providing ease of use.

  • OptiPoint 100 advance telephone automatically stores the numbers of the last 20 unanswered calls.

  • Excellent voice quality in both hands-free and open listening modes using special digital signal processor (DSP) technology and acoustic algorithms for echo cancellation.

The Siemens IP phones can be upgraded with software (a good feature in a highly volatile technical environment). Other examples of IP telephones include InterPhone by DSG Technology and Cisco's IP phone 7960 (see Exhibit 2). Cisco's IP phone can also accept firmware updates via download.

Exhibit 2: Cisco IP Phone 7960 (Courtesy of Cisco Systems.)

When evaluating IP telephony solutions, voice quality is obviously critical. A standard measure, MOS (mean opinion score), is used by the industry to determine the subjective quality of the telephone conversation. The ranking is from 1 (very bad) to 5 (perfect, undistorted toll quality sound). One firm, NetIQ, has a well-developed monitoring system, VoIP Assessor, that allows simulation of VoIP traffic and an assessment of its quality. According to a recent Business Communications Review article, "The Assessor software measures delay, packet loss and jitter, and produces a report showing call quality by day of week, location, network cause, etc. …There's been years and years of research that went into that ITU standard, so it really is a fairly scientific answer: You run this kind of traffic through this network with the parameters you told us, and here's what call quality's going to sound like." Call quality is expressed as MOS.

One clear indicator of the direction of the industry is the fact that Sprint, a major long-distance carrier, has decided to build out all its local telephone service using VoIP technology. Certainly the older technologies will co-exist for years, but the world is moving quickly to a fabric of interlacing packets that will carry information without regard to its original form.

Voice and data convergence

Voice and data convergence
One of the recent data networking trends is called convergence. Convergence means that different signals such as voice, video, and data are transmitted over a single medium. On the consumer level, Web TV is an example of convergence; cable TV and the Internet are provided across a single cable. At the business level, many companies are migrating their voice long-distance traffic across their data networks.

Businesses have traditionally carried their voice and data traffic over separate networks. The phone companies assigned separate account managers to handle a business’ voice and data needs. The services had separate contracts and were billed separately. As part of the recent streamlining effort of the phone companies, voice and data services now share the same account manager, the same contract, and the same invoice. But the greater change is that voice and data now ride the same phone line.

Voice over frame relay
The main benefit of voice over frame relay (VoFR) is that long-distance calls are free. VoFR is normally only used to carry intracompany long-distance traffic or international long-distance traffic. The latency of packetswitching technology affects the call quality (i.e., conversations may be choppy).

Latency is a term that describes the transmission delay due to the speed of the media and the processing time of the network equipment, such as routers. Each stage in the network may only add milliseconds of delay, but the combined latency may be enough to distort the sound of the phone call. VoFR is, therefore, rarely used for “front office” applications. However, businesses with lots of intracompany long-distance calling can significantly reduce their long-distance billing. By moving their long distance across their frame relay network, they will eliminate the long-distance cost altogether. If they do not mind slightly compromising call quality, thousands of dollars can be saved.

Voice over Internet
Voice over Internet (VoIP) is the same concept as VoFR, except the voice calls are converted to data packets and sent along a network that uses Internet Protocol (IP). The Internet, or a private WAN using IP, are both examples of IP networks. The same latency problems previously described with VoFR apply with VoIP.

On a much smaller scale, cost savings can be achieved by using one of the Internet’s free long-distance Web sites such as http:// www.net2phone.com or http://www.dialpad.com. These services allow a person to make free long-distance calls over the Internet. Most of them limit the destination of the call to the United States, but a few of these services have roots in the Far East and may include Korea or Taiwan as approved calling destinations. Internet phone calls often experience a lot of noise, similar to a shortwave radio conversation, or international calls 5 or 10 years ago. The call quality is poor, but you cannot beat the price.

ATM
ATM is a high-speed packet-switching telecommunications service. ATM is typically used only by very large businesses such as Fortune 100 companies, major universities, and telephone companies. Telephone companies use ATM technology in the “backbone” of their networks. A voice phone call from New York to Tokyo will probably be converted to ATM packets as the data travels along an undersea phone line lying at the bottom of the ocean.

ATM is a high-cost service, designed for high-volume users, and will therefore not be used by most businesses. According to the Vertical Systems Group, only slightly more than 35,000 enterprises worldwide are currently using ATM services, while frame relay has more than 1.2 million subscribers.

Why is ATM so fast?
ATM carries voice, video, and data at speeds up to 622 Mbps. Such a high speed is due to three factors: asynchronous switching, cell length, and the use of hardware in switching. “Asynchronous” means the service transfers different data at different times and can process multiple jobs simultaneously.

ATM’s fixed-length packets, called cells, make ATM more efficient than other technologies, such as frame relay. The size of each frame relay packet must be processed, while ATM networks waste no time figuring out how large or small a packet is. ATM networks expect each packet to be 53-bytes long, and they rapidly move these packets up and down the network.

Another advantage of ATM over frame relay is that the switching is controlled in the network hardware, instead of the software. These three advantages make ATM a very fast data networking technology.

Although ATM may be a fast technology, it is also a costly one. Installing an ATM network is very expensive, and the monthly charges not only include fixed charges for the network, but also usage on an ATM network. ATM is only a cost-effective technology for extremely large businesses.