Phone and Communications Systems
For the Solo and Small Firm

By Aaron W. Brooks

Certain inventions and discoveries mark watershed moments in our advancement as a civilization. The telephone is without question among the most significant of these. The precise moment of its invention and the individuals most deserving the credit have been a matter of popular debate for well over 100 years. Yet we all recognize the historic statement of March 7, 1876: “Mr. Watson, come here, I want to see you.”

What follows is a brief but systematic outline of the equipment used in modern communications. In general terms, communications equipment might best be understood by dividing it into two broad categories: that which is not Internet-based and that which is.

Non-Internet Telephonic Communication

Plain old telephone service (POTS). This is the most basic form of organized, systemic telephonic communication. At its most rudimentary, a POTS communication system is nothing more than a pair of speaker/microphone devices connected together with copper wires. In fact, the first system of widespread telephonic communications consisted simply of telephonic equipment literally hardwired together; a separate telephone and wired connection was necessary for each person with whom one wished to have telephonic communications. This rudimentary system was gradually replaced throughout the 20th century by a universal system of call switching. The telephone switching system began with operators literally plugging and unplugging the cords necessary to connect telephone pairs, and eventually it grew into the sophisticated system of automatic electronic switching that we call the “public switched telephone network.”

Public switched telephone network (PSTN). This system requires little explanation, as it is the form of telephonic communication with which most readers will be familiar. It is the modern global system of switched telephonic communication that is not Internet based. Thus, it would be appropriate to say that PSTN is the current system of POTS used throughout the world. Although the line between POTS/PSTN and Internet-based communication is becoming blurred, this distinction is currently fundamental to understanding modern communications equipment generally. We traditionally think of PSTN as the analog system of landline telephone connections to which most small business and residential telephones are connected. However, much of the signals transmitted over the PSTN, as well as the switching system that links those signals, are now digital. Additionally, many other telephonic systems (cellular and satellite networks, for example) now connect to, or through, the PSTN, further blurring the historic distinction.

Local loop circuits. The local loop circuit, sometimes called the “subscriber circuit,” is the physical wire that runs between an office or residence and the PSTN. The local loop is also sometimes referred to as the “last mile” and is normally a copper line that works well for audio communications but does not have the ability to carry large amounts of data such as video or computer files. Many forward-thinking communities are beginning to adopt a movement often called “fiber to the home” (FTTH) that replaces the traditional copper loop with a fiber optic connection capable of carrying vast amounts of data. A local loop connection alone is enough to connect multiple telephones as a single shared line; however, a new local loop connection is required for each telephone that has a separate line. This limitation can be overcome if one installs an internal switching service, such as the private branch exchange (PBX) system described below.

PBX systems. Private branch exchange (PBX) networks exist separately and independently from other telephone networks. PBX systems are normally installed within a single organization to permit its members or employees to make internal calls that do not ride across wires outside that organization. Thus, no external service is required to support internal PBX communications, which generally reduces cost and increases security (although more recent forms of PBX are often hosted or outsourced to a PBX provider, giving companies the convenience of internal PBX features such as extension dialing, internal messaging, and internal call forwarding without the maintenance hassle).

A PBX system consists of a switching device installed on the premises of the organization. This device is connected through wires to PBX outlets installed throughout the building. The internal switching device then controls the interconnections between telephones, fax machines, modems, and any other devices that act as extensions on the system.

PBX systems are connected to the global PSTN through one or more local loops as described above, which in this context are often called “branch” or “trunk” lines. This allows an organization to lease fewer outside lines from a telecommunication company than it would need if each extension were connected directly to the PSTN.

Virtual PBX systems. There is a growing telecommunications trend known as “virtual PBX,” which is a hosted service driven primarily by software. These services utilize the acronym “PBX” because they simulate much of the functionality of traditional PBX systems; however, physically the two technologies have little in common.

Virtual PBX systems work by routing all incoming and outgoing calls through a third party’s call management equipment and software. By doing this, all incoming and outgoing calls can be controlled by the virtual PBX system and routed in a much more sophisticated manner than a system based simply on several independent lines or cell phones. Thus, inbound callers are actually dialing into your virtual PBX provider’s call manager and then are routed by your virtual PBX provider through your internal phone system. Outbound calls are placed by first connecting to the virtual PBX provider, who then makes the outbound call on your behalf. Because the virtual PBX system always has control of the call, each call can be routed or conferenced among all phones on the system.

A virtual PBX system can simulate full PBX functionality without the need to install equipment or software. For example, the system can be configured such that inbound callers are first greeted with a receptionist or pre-recorded message. When the caller is transferred to your extension (either by entering your extension number or allowing the live receptionist to transfer the call), the virtual PBX system can ring it through to your deskphone, cell phone, and home phone, either simultaneously or sequentially. If the call is not answered, it can be routed to voice mail (which in turn can be sent to you as an e-mail attachment). Similarly, internal users of the system can dial each other using traditional internal extensions and can route external calls between themselves. In this manner, a virtual PBX system can be a simple and efficient way to link groups of cell phones together as if they were part of a full PBX implementation.

Cellular networks. Cellular networks operate in a manner that is similar to traditional PBX systems, in that most cell phones are connected to a separate, privately owned network of base stations that manage and direct the communications traffic. Also like PBX systems, each cellular network then connects to the PSTN to permit communications to be routed to PSTN phones or cell phones on other cellular networks.

Although cell phones are useful and critical to anyone’s practice, they have not traditionally been considered as an exclusive telephonic solution. This is changing. Cell phones are becoming more user-friendly, ergonomically designed, moderately priced, and feature-rich (consider specifically “smart phones” that synchronize in real time with e-mail systems and have the ability to run popular desktop applications, such as Word and Excel). Moreover, the virtual PBX hosted services described above allow multiple cell phones to be connected as though they were extensions in a traditional PBX system, whereby calls can be transferred internally, forwarded, and conferenced just like any other office system. Furthermore, one may purchase cell phone cradles with handsets that essentially create the look and feel of a traditional desktop phone but are powered by the cradled cell phone.

Internet-Based Telephonic Communication

Internet-based telephonic communication is often called “voice over Internet protocol” or “VoIP.” Unlike PSTN, PBX, and cellular networks (which generally consist of privately owned networks of equipment that are interconnected and switched in a managed fashion), VoIP systems normally operate directly over the sprawling, often-unmanaged expanse of the Internet itself. Like PBX and cellular networks, VoIP systems must be patched into the PSTN to allow VoIP users to communicate fluidly with traditional landlines, cell phones, and extensions on internal PBX systems.

VoIP service is often thought of as a work in progress. Although the service availability is largely reliable and the sound quality is generally clear, problems sometimes arise. This is owing to the basic nature of information flow on the Internet, which is random and nonsequential. All information traveling across the Internet does so in the form of packets, which may travel widely different routes and arrive at their destination in a different order than that in which they were sent. Thus, to form a cohesive and coherent message at the destination point, the packets must be reassembled in their original order. When the information in question is a live voice communication, the signal being received at the destination is, from time to time, garbled or partially dropped because of a phenomenon called “latency.” Such problems occur much less frequently with communications traveling through the PSTN because PSTN traffic moves in a linear fashion through carefully orchestrated and managed switches designed specifically for this purpose. Yet the technology of VoIP has improved significantly enough to make it a popular and widely used alternative in both small and large offices throughout the world.

Three basic types of VoIP systems are available: IP phone systems, analog telephony adapter (ATA) phone connectors, and softphone devices. It is the author’s opinion that an ATA phone adapter setup would most likely be the best choice for a solo firm wishing to implement VoIP. Small- to medium-sized firms would probably be better served with a managed IP phone system or a virtual PBX subscription powered by cell phones and desktop cradles, as described above.

IP phone systems. IP phone systems are driven by phones that have processing equipment and software built into them and that plug directly into a standard Ethernet port, just like any other Internet appliance. To be effective in a business environment, however, the IP phones must be connected internally with a call management device, conceptually similar to the PBX internal switching device described above. This device is often called an “IP PBX” (some traditional PBX managers can be reconfigured to support IP communications as well). The IP phones can also be managed using a standard server running IP PBX software designed for this purpose.

An IP PBX system transmits communications both internally throughout the organization and externally across the organization’s Internet connection and through a gateway to the PSTN. The system makes efficient use of space and resources because it allows traditional POTS, VoIP, and Internet connectivity all to be delivered to one’s desktop using a single wire.

ATA systems. An analog telephony adapter (ATA) is a device that converts the traditional signals of a POTS telephone into VoIP data that can be transmitted over the Internet. Most ATA devices are small boxes that have a normal telephone jack on one side and an Ethernet port on the other. Communications into and from the ATA device are delivered to and managed entirely by the VoIP service provider, so no equipment other than the ATA device itself is necessary to set up and operate the system. Because each phone is connected directly to the provider through a separate ATA device, however, no internal centralized network will exist. Thus, larger organizations that need the functionality of traditional PBX systems are not likely to function as efficiently with individual ATA devices on each desk and probably require a centrally managed IP PBX system supporting full IP phones.

VoIP phone systems, whether based on individual ATA devices or centrally managed IP phones, come with many features that are not readily available in phone systems that are not Internet based. For example, VoIP phones are very portable; a VoIP phone can be plugged into any Internet connection and function as if it were still on the user’s desktop. Also, VoIP phones are generally driven by software that includes at least the following enhanced features: (1) a call log that tracks all incoming and outgoing calls along with their start and stop times and duration; (2) simultaneous ring, permitting a single number to ring multiple phones at the same time—thus, both your desktop phone and cell phone can ring anytime your direct number is called; (3) sequential ring, permitting a single number to ring a series of phones in a specific order and, if none answer, send the call to voice mail; and (4) enhanced voice mail that delivers a digital recording to the user as an e-mail attachment, together with a written e-mail transcription of the voice mail.

Softphones. A softphone is simply a software application that one installs to facilitate telephonic communications directly through the computer. The software translates voice and video collected with a microphone or webcam and transmits the data over the Internet as would an IP phone or ATA device. Some softphones facilitate direct communications from one computer to another, and others provide a more managed service with VoIP benefits as described above. It is also possible to communicate with POTS devices by sending softphone communications through a gateway to the PSTN.

The primary drawback of softphones is that they are driven by, and therefore dependent on, use of a computer. Thus, for most practitioners, conversion to softphones entirely as a communications solution would be a major shift away from our historical thinking of the telephone as a stand-alone device. Also, just like any software, softphones are subject to typical computer security risks, such as hacking and viruses; thus, one might question whether softphone communications offer the same level of security and privacy for which traditional POTS communications systems are known. By the same token, a softphone’s integration with the computer can be a benefit in that you can have available a full-featured phone system anywhere your laptop has Internet connectivity.

Sometimes softphone software is used to supplement the main VoIP solution, rather than replace it. For example, one might implement an IP phone system using desktop hardware but also allow users to download the corresponding softphone application. Doing that would allow users to replicate their desktop extensions on a laptop and receive calls directly through the PC. Most modern softphone applications contain the main features of a stand-alone phone system, such as speed dialing, call forwarding, conferencing, and multiple-line holds and transfers. In addition to that, however, a softphone application can provide tight integration with the existing PC contact list and easy drag-and-drop dialing.

The Bottom Line

Which communications hardware is best for you depends entirely on your circumstances. However, this author would advise sole practitioners to look closely at an ATA-device-driven service, such as Vonage business-class VoIP service ( The cost of such a service will be comparable to a POTS line, will not require additional hardware, and will offer all the call management benefits of VoIP service that are described above.

Firms with three or more attorneys should consider cell phones networked through a virtual PBX system. Such an arrangement still provides the call management benefits of a VoIP service but also simulates the internal switching mechanism of a full PBX or IP PBX installation.

As your firm size increases, a point may be reached where only a full PBX or IP PBX installation will handle your capacity economically. If you think you may be at that point, contact a local network management professional who routinely provides VoIP solutions. Such a professional should have the ability to review your current invoices and communications expenses and make recommendations for service changes.

Aaron W. Brooks practices with Holmstrom & Kennedy, P.C., in Rockford, Illinois. He may be reached at

Copyright 2009

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