By: John Shepler

For years, businesses of all sizes have been transitioning to VoIP phone systems. While some are thrilled with the switch, others find the call quality lacking, with muffled audio and challenging conversations. The technology is the same, so why does VoIP performance vary so greatly? Let’s investigate.

What is VoIP?

VoIP, or Voice over Internet Protocol, transforms phones into computer accessories, saving money and enabling features impossible with traditional phone systems. While powerful, network voice is more susceptible to degradation than analog phones.

Traditional Phone Systems

Business phone lines, often called POTS (Plain Old Telephone Service), use dedicated copper wires from each phone to the telephone company. This setup leads to high costs for larger businesses due to internal call charges.

To combat this, companies install phone switches. Small businesses use Key Telephone Systems, enabling internal calls over shared lines and access to multiple external lines. Larger companies opt for PBX (Private Branch Exchange) switches, managing a pool of external lines assignable to any phone.

With few phones and dedicated lines, the phone company handles call switching. With numerous phones, businesses manage internal calls, requiring specialized wiring, Key/PBX equipment, and multiple analog lines or a digital PRI trunk.

VoIP: A Different Approach

VoIP phones connect to the company’s LAN, eliminating the need for a separate phone network. Call switching is handled by an in-house VoIP PBX, IP PBX, or a hosted PBX from a provider. This “hosted” model, similar to web hosting, involves monthly payments instead of equipment management.

VoIP Phone Line Requirements

All VoIP phones connect to a local network, whether a small office network or an extensive corporate LAN. Regardless of the network size, high-quality performance relies on shared principles and needs.

Since the network is shared, ensuring high-quality voice calls requires prioritization. Unlike dedicated analog lines managed by the phone company, VoIP performance becomes an IT responsibility.

Sufficient bandwidth for all devices is crucial, but prioritizing voice packets over data is equally important. Prioritization prevents choppy calls, even if file downloads slow down. The network also needs low latency, minimal packet loss, and jitter to ensure clear VoIP conversations.

3 Types of VoIP Phone Lines

Unlike the uniformity of analog lines and ISDN PRI trunks, VoIP phone lines come in various forms, from basic Internet VoIP to dedicated SIP Trunks and private MPLS networks.

The Internet as Your Phone Line

For cost-conscious home offices and small businesses, broadband Internet serves as the connection to the VoIP provider. Sharing the connection with computers, a WiFi router, and VoIP phones requires a router with Quality of Service (QoS) features to prioritize voice traffic.

While cost-effective, using the Internet as a phone line presents challenges. Designed for reliable data transfer, the Internet lacks built-in voice prioritization. Shared broadband connections like DSL, Cable, Satellite, and Cellular can lead to inconsistent call quality depending on network traffic.

Dedicated Internet access (DIA) options like T1 or Ethernet over Copper offer improved reliability by avoiding congestion caused by other users on the shared connection. However, they remain susceptible to congestion on the broader Internet.

Private Line VoIP Service

Businesses prioritizing high-quality phone service often choose SIP Trunks for their predictability. Similar to traditional analog and PRI lines, SIP Trunks are dedicated, unshared digital broadband connections. The name derives from their support for SIP (Session Initiation Protocol), the VoIP call switching system.

A basic SIP Trunk, often a T1 line connecting the business network to the provider, supports numerous simultaneous calls or combined voice and internet traffic. Lower-priority internet traffic utilizes remaining bandwidth, making it a cost-effective solution for smaller businesses.

Larger SIP Trunks, utilizing copper or fiber optic bandwidth, cater to larger companies and call centers, providing the necessary capacity for high call volumes.

Voice over MPLS Networks

Large corporations with multiple locations benefit from VoMPLS (Voice over MPLS networks). MPLS offers a private network solution with regional, national, or international coverage. Network providers ensure consistent Class of Service, bandwidth, low latency, and minimal packet loss and jitter for all customers.

VoMPLS functions similarly to SIP Trunks but eliminates the need for dedicated lines between locations. Businesses connect each location to the MPLS network through an access line, achieving cost savings, especially for international calls, while maintaining high performance.

Looking to improve your telephone system, reduce costs, or enhance features? Explore the range of VoIP telephone solutions available.