PBX and SIP: Learn the Basics

PBX is essentially a traditional switching and routing system that sends telephone signals to their intended destination. With telecom providers and broadband networks integrated under the same umbrella, today’s companies can enhance business communications using a commercial-grade, network-based PBX system. Doing so is also easier and more affordable than ever because, like most other business and networking technologies, PBX telephony is moving to the cloud at a blistering pace.

According to a report from Eastern Management Group, hosted PBX made up 40% of all PBX system purchases by American mid-market companies during 2019 and 2020, and those numbers are rising every day. 

Accordingly, modern business owners must become familiar with the underlying infrastructure of PBX deployments and IP-based routing. These are not just alternate communications platforms – rather, they’re the new wave of full-scale, enterprise-grade telephone systems that can function directly over Tier-1 carrier networks.

Modern PBX systems also expand functionality while enabling access to company communications networks with one’s own device just as well as with office property. Read on to learn how on-demand PBX and SIP platforms can route calls as reliably as traditional telephone systems while expanding the fundamental capabilities of enterprise-grade communications technology.

Modern PBX Systems Explained

In the past, if a large business needed hundreds of extensions, it required an independent switching facility. A telephone exchange for a large company could take up an entire room, where mechanical circuits switched calls to connect subscribers.

Back then, it didn’t make sense to run hundreds of lines from the phone company to every desk that required a phone. Therefore, the companies ran trunk lines from an on-site switching facility. From there, the trunk lines served each extension. This arrangement was known as a Private Branch Exchange (PBX).

PBX evolved from the Key Telephone System, which previously required manually selecting outgoing lines. Connections became more automated with PBX, which used device extension numbers to more easily and efficiently select the appropriate lines between callers. It became a single streamlined business tool for routing calls through network channels, such as VoIP or ISDN.

This allowed companies to essentially create and customize their own telephone network. Employees could collaborate internally with each other and externally connect with clients, shareholders, and business partners without relying on switching facilities, which cuts down the amount of physical equipment required.

Today, the infrastructure needed to expand the capabilities of mass communications networks is again shrinking – and by some estimates, set to account for 40% of all network-driven unified communications sales.

Transmitting Calls Over the Internet

As the internet continues to fundamentally change the way business is done, cloud-networking infrastructure is bringing cutting-edge phone networking tools into the hands of even budget-conscious SMBs. A startup company with almost any number of extensions can now set up a commercial-grade PBX system without the need for lots of equipment, real estate, or cash – and they can do so in mere minutes.

The key to this is Voice over Internet Protocol (VoIP), which lets companies transmit calls as data packets over the internet. This method replaces the need for traditional phone lines because VoIP allows you to send voice and other communications through data packet exchange, similar to almost any other web activity.

Not all VoIP providers are created equal, though. Some will restrict calls to only those using the same service, while other providers enable VoIP calls to any local, long-distance, mobile, and international phone number. Further, some providers may only allow connection through a computer or special VoIP phone, but there are also VoIP adapters that work with traditional phones.

As VoIP is brought to the cloud, the most dedicated service providers are delivering much more polished PBX solutions that are just as user-friendly as they are versatile and capable.

Getting the Most From VoIP

Despite the improvements of VoIP-based PBX over the Key Telephone System, businesses still need to route calls differently than regular telephone users, sometimes in highly intricate ways. Nowadays, VoIP PBX technology can redirect phone calls through virtual endpoints over the internet much more fluidly and automatically.

The most advanced PBX systems also do much more than transmit voice signals. With PBX, it’s possible for companies to streamline their entire operations strategies, expanding their communications capabilities with game-changing new features, including:

• Video calls
• Conference calls
• Instant messaging
• Thorough Call Data Records
• Software and app integrations
• Direct Inward Dialing (DID) options
• Flexible, need-based pricing
• Emergency 911 support
• Near-instant scalability
• Bandwidth controls
• A simple, user-friendly control panel
• Oversight of the entire network from a single pane of glass

And this is just the beginning. As the application of VoIP continues to advance and integrate more deeply into companies’ entire cloud infrastructure, the possibilities of cloud-based PBX are virtually limitless.

Related: SIP Trunking 101: The Fundamentals

SIP – How PBX Connects Extensions

Just as an analog enterprise-grade PBX system required trunk lines to manage switching facility operations, extension lines over internet-based PBX are trunked through a process called Session Initiation Protocol (SIP).

Used by over 50% of companies, SIP is how digital PBX systems connect to the internet. SIP initiates, maintains, modifies, and terminates real-time voice and video connections over the internet. Because it is fundamentally digital, the amount of infrastructure is hardly any different from any other server-based networking service, and the system can be customized and continually modified with incredible ease.

SIP and PBX Go Hand-In-Hand

To support telephony and other communications infrastructure to the cloud, businesses must partner with a reliable and experienced SIP trunking service provider. For companies with legacy phone systems that work just fine for their purposes, SIP can still route calls by using a SIP analog/digital gateway.

Such a gateway allows companies relying on traditional PBX trunking to still enjoy many of the features of a modern telephony PBX system built from the ground up. Yet compared to traditional hardlines, SIP trunking is more reliable, flexible, and easier to manage. It’s also fast and easy to deploy across an entire organization, even when it is much less dependent on location.

Because of these benefits, many large and smaller organizations have already transitioned to cloud-based communications, and many more are following suit. This technology is becoming increasingly popular because it gives businesses greater control over their communications, which take place in an increasingly digital space. For instance, SIP enables enterprises to manage certain features internally and through a single user-friendly network-control interface, such as:

• Call routing
• Cloud-based services
• Cloud-based systems
• External calls
• Internal calls
• Sessions

SIP trunking also lets business leaders develop customized solutions for their own unique needs with greater precision and oversight.

Typically, businesses use a handful of conferencing and PBX services, and the best SIP-trunking provider ties those settings together. This technology is especially vital where a significant number of employees are now working from home, remote locations, or both.

As more companies gravitate toward digital communication, a growing number of SIP service providers enter the market. However, this flood of potential options creates a new problem for business leaders: finding a SIP trunking company they can trust.

Which SIP Service Provider Is Right for You?

A SIP-enabled PBX system is a cost-effective way to improve communication for your business. However, the popularity of the service has somewhat flooded the market with inferior products and services. Because of this, it’s more difficult for business and IT leaders to figure out who to turn to while also learning a new system.

Before you choose a provider, there are a few things you should investigate. Most generally, you should ensure your service provider supports commercial-grade communication quality. If every call isn’t crystal-clear, the other benefits offer no value.

Also, look for a provider with a redundant infrastructure to maintain service reliability. Additionally, you must pay attention to the cost of the service. For example, it costs less to make local and international calls over a SIP network. It’s a red flag if a provider tries to charge you close to or more than what you paid using traditional phone service.

Above all, save yourself an immense amount of time and trouble by counting out SIP providers who use sub-Tier-1 providers. Because your company’s revenue is on the line, you can’t afford to trust anything less than the most reliable telecom networks with your critical communications.

Be on the watch for the following signs of top-tier SIP providers. You likely won’t know what to look for, unless you’re already in the competent hands of a telephony industry veteran.

• Automated provisioning for streamlined, ready-built PBX systems
• Servers dedicated to routing only SIP messages, ensuring bare minimum latency
• Flexible pricing models that allow you to pay for only what you need and try new features with minimal risk
• Real-time Call Detail Records (CDR) database population and bulk CDR downloads
• Proxy of media to the client’s server at their request
• Large DID (Direct Inward Dialing) footprint
• US48 (lower 48 states) phone porting
• PSTN forwarding
• On-demand channel upgrades/downgrades
• Quality of Service (QoS) traffic prioritization options
• Secure payment processing entrusted to reputable tokenized payment systems

It’s also essential that your SIP company’s platform works with standard soft switches and PBX systems. Be sure you rely only on a SIP trunking service that allows you to easily and efficiently expand without the need to invest in additional equipment. After all, one of the keystone strengths of telephony is that it can help your business become more independent from physical equipment than ever before.

Related: How to explain to your customers how SIP works in VoIP

Equally Impressive Service

Once you narrow down your choices, you should take a closer look at your candidates. For example, find out about the company’s developers and IT experts. You want to settle on a SIP trunking firm that employs dedicated, passionate professionals who are available to you at any time.

Be sure you are receiving attentive customer support from experienced SIP-trunking experts who have been at the leading edge of the industry. While today’s SIP-enabled PBX systems are much easier to use than previous iterations, a fully featured suite of services can be highly sophisticated.

Only a highly experienced team of dedicated technology professionals can ensure you achieve the best results with your new cloud-based PBX system. SIP industry leaders are also more capable of offering solid prepackaged solutions. These products serve as a launching point to understand the services that will work best for your organization.

Because the SIP-enabled PBX service is flexible, you can easily make changes as needed – and with the right support, you’ll be able to zero in on exactly the right features for your company’s needs.

Elevating the Conversation

At SIP.US, dedicated telecom experts and software developers have worked tirelessly to create the highest-performing and most reliable PBX service possible. We likely already have the pre-designed PBX solution necessary for seamless deployment across your entire organization – and if not, we can quickly customize one.

Our expert service technicians can also show you how to achieve maximum cost savings and boost communications efficiency for your enterprise, just as we’ve done practically since the beginning of internet-based PBX systems.

Find out how SIP.US can introduce your organization to a new level of commercial-grade PBX service and get started today.