Telecom DID Numbers
and SIP Trunking Explained

When you understand some key telecom industry terminology, selecting carriers and services for your enterprise can actually be a rewarding experience. The more you know about PBX, DID numbers and SIP trunking, to name a few telecom terms, the better prepared you’ll be for advancing your company as technology evolves. These particular acronyms are some of the most important for business operations and overall productivity. Since PBX is a primary phone system supporting DIDs and SIPs, this concept is worth understanding as well.

A Private Branch Exchange (PBX) system is a private company phone network with complete versatility for internal and external calling options. A PBX is popular because the communications channels are broad including VoIP, ISDN, or earlier-style analog calling. Voice over Internet Protocol (VoIP) communication allows users to make phone calls over the Internet from their computers. Versatile Integrated Services Digital Network (ISDN) is the communications standard for simultaneous transmission of network services including digital voice, data, and video over public switched phone network circuits.

A PBX system is considered an excellent business grade phone system for high-end voice features. With PBX, staff can easily communicate internally (within the company) or externally (outside the company) using the most efficient communication channel.

Direct Inward Dialing (DID) is simply a virtual phone number that routes incoming calls to your company’s existing phone lines. This feature was designed so your employees could have a direct phone number without the need for many physical cost-bearing phone lines. Incoming calls based on these DID numbers lets callers connect directly to a phone extension without operator assistance. The staff enjoys many advantages and benefits in having their own virtual DID phone number.

- Flexibility. You accommodate your staff across locations with many phone numbers and full features even though your DID number may be established in one central location. For example, you may require only 6-8 physical lines and yet have dozens if not hundreds of DID numbers.

- Convenience and Speed. There is no compromise for convenience and speed with DID numbers. Users transparently and concurrently send and receive calls in a manner they always have, if not more efficiently depending on legacy systems they used.

- Cost Savings. Even with multiple phone numbers, you need only a minimal number of physical trunk lines, which in turn results in a potential for greater cost savings. As well, less equipment and maintenance are required for extended cost savings.

- Communications Features. Staff enjoys standard communications features as well as internal extensions, customized phone numbers, local-appearing phone numbers, and more.

For enterprises both small and large, direct inward dialing capabilities produce positive results. Not only do employees enjoy added conveniences, companies benefit in ultimate cost savings. So, why do you need SIP? Session Initiation Protocol (SIP) offers some other unique advantages you need to understand as well.

Session Initiation Protocol (SIP) offers companies Voice over Internet Protocol (VoIP) technology along with streaming media services. While there are many variations in service levels based on the Internet Telephony Service Provider (ITSP), a SIP-based private branch exchange is a positive choice for many business entities. A business SIP trunking service allows organizations to route phone calls from a PBX phone system to a Public Switched Telephone Network (PSTN). Seamless SIP trunking involves simple protocols delivered by your provider versus a more resource-heavy physical trunking system. Like DID numbers, Internet based calling comes with many advantages and benefits.

- Reliable. SIP trunking is removed from most physical disasters that may be a factor with a physical trunking system. Inclement weather, power pole incidents, or inexperienced technicians are not as likely to interfere with an Internet call or a multimedia conference among remote participants.

- Mobile. SIP trunking provides flexibility in connecting staff through mobile devices in addition to on-premise solutions. When using SIP, mobile backups may also be established in case of an outage.

- Scalable and Cost Efficient. With SIP, companies invest in a scalable and cost-efficient alternative for telecommunications. These benefits are often described as the most significant. Internet pricing is usually straightforward, easy to understand, and billed per user. Costs are easy to forecast based on the volume and type of calling services required.

- Minimal Hardware and Maintenance. With SIP, there are minimal costly physical hardware requirements and almost zero maintenance needs. Adding staff to your organization generally requires little more than a handset connection and a software tweak in a very short time.

Business SIP trunking may be the perfect solution depending on the variables within your organization. It is extremely efficient as long as Internet configuration and bandwidth are in place and function well through a reputable VoIP or SIP trunk service provider. If you use legacy telecommunications systems, a SIP migration is a consideration that may involve some added costs and temporary downtime. Making a switch to SIP could be a valuable investment.

Did you know that PBX was originally formed after PABX, or Private Automatic Branch eXchange, as early as the 1960s? For the first time, people could call internally on their own without the need for operators. Finally, in the 1990s, PBX became integrated with computer technology as a more convenient and cost-efficient call handling solution. Companies could now easily modify and expand their phone systems. New features such as auto attendants, data integration, increased phone apps, and new concepts about packet switching technology became apparent—all the precursors to today’s VoIP PBX communications systems.

As packet switching technology evolved, VoIP was a clear leader for many facets of business including voice and data transmissions. Soon, better transmission methods surfaced, but VoIP remained a superior solution for business communications. It was also compatible with many telecom provider solutions.

You may not realize how well SIP trunking works with VoIP systems or that DID is often less expensive when purchased with SIP trunking. A valuable SIP trunking service provider is a telecom company that offers SIP trunking including outbound and inbound calling along with DID numbers for added convenience. DID may also be referred to as a “direct line” even though callers bypass a main operator for immediate connection to the number called. When used in conjunction with a PBX, DID trunks forward the last digits of the phone number to the gateway and route to the desired extension. When researching SIP providers, look for a DID footprint and available numbers that meet company needs. PBX SIP trunking is a proven integrated solution. While today’s PBX solution is completely transformed from the 1990s, we still use the same original principles.

While companies today have multiple choices for expert communications, most businesses have migrated to VoIP based business telephone systems. Both on-premise and tailored hosted VoIP solutions are available to meet organizational communications needs. With VoIP today, businesses function more efficiently, at lower costs, and with better comprehension. All we know about the VoIP of tomorrow is that it will likely be based on the amazing VoIP of today.

As the economy spikes and dips, technology advances, and competing online sites arise daily, companies are experiencing an ongoing state of transition. The choice to migrate to and maintain a current business phone system that is compatible with business needs is critical to modern day success. With many telecom solutions on the market—both on-premise and hosted—there is a lot to learn before making a switch. Find a reputable provider with experience in the field to guide you for a telecom strategy that meets your needs. There is a unique solution for every organization. Do not rely on a “one size fits all” model to take your company into the next generation.