SIP vs. VoIP: What's the Difference and Which is Best?
Today's business communications involve a lot more than just voice calls.
While phones are still a critical tool for communications, professionals use a lot of different technologies to converse. On a given day, it's not uncommon for the average employee to rely on phones, email, mobile apps, chat, text, and video conferencing.
Technological advancements have expanded the options companies have in business phone systems. Increasingly, organizations are switching from dated options like Primary Rate Interface (PRI lines) to more integrated options like Voice over Internet Protocol (VoIP) to save costs.
Switching to internet-based phones is the right choice for some companies, but VoIP-only isn’t a robust enough solution for many businesses today. Many organizations can benefit more from a Unified Communications approach, which supports voice, text, conferencing, mobility, and other forms of communication.
If you’re evaluating new business phone systems, you may be wondering what the difference is between Session Initiation Protocol (SIP) and VoIP, and which is best. In this post, you’ll learn the pros and cons of each of these approaches, and how to know which is the best fit for you.
SIP vs. VoIP: What’s the Difference?
SIP vs. VoIP isn't necessarily a direct comparison. While VoIP is a term that can be used to describe any internet-based phone service, SIP is a communications protocol that is used for most types of VoIP deployments. The technology for VoIP has roots in the 1970s but has developed significant popularity as a business technology over the past 10 years.
VoIP is a broad term used in reference to any phone call made over the internet instead of traditional telephone lines. VoIP relies on data connectivity to transmit voice packets instead of the public switched telephone network (PSTN).
SIP is a protocol used to initiate, maintain, and terminate multimedia communication sessions in VoIP applications. SIP protocols support the signaling and control of voice, video, and messaging applications. Hosted SIP Trunking service is generally provided by a hosted Unified Communications vendor who may offer VoIP and Unified Communications as a Service (UCaaS).
SIP vs. VoIP is Not the Most Effective Question
While all SIP is used to support and scale VoIP, not all VoIP is backed by SIP technology. SIP is just one protocol that can be used in business VoIP to scale communications beyond voice-only calling to support video conferencing, instant messaging, text, and other multimedia communications. It does happen to be the most prevalent protocol, though some vendors interpret SIP in different ways. This is changing, though, as interoperability has been so critical to long term business success.
Pros and Cons of VoIP
VoIP is a broad term that can be applied to describe any internet phone service, from low-cost residential service to complex implementations of Unified Communications tools for the enterprise. Since the quality and features of VoIP can vary significantly, each of the pros and cons can also depend on the type of service.
However, evaluating the pros and cons of VoIP in comparison to SIP is not useful. To best understand how VoIP stacks up to VoIP with SIP, it's wisest to evaluate the pros and cons of business internet phone service that includes only voice communications (VoIP-only), instead of multimedia features (VoIP with SIP).
- Low initial investment cost.
- Ongoing cost savings with predictable, flat rate monthly billing.
- VoIP systems are highly portable and don't need on-site installation.
- Many basic VoIP service plans offer limited features such as caller ID, call waiting, and call forwarding.
- Most VoIP providers do not require long-term service contracts.
- Requires bandwidth for service availability and sufficient call quality of service (QoS).
- Some basic VoIP services may not offer mobile integration or mobile apps.
- Voice-only service lacks support for multimedia communications.
- Cannot be integrated with applications such as Salesforce, DropBox, or Microsoft Office.
Pros and Cons of VoIP with SIP
Switching to SIP from traditional PRIs can offer organizations the ability to achieve immediate cost savings, and scale to unlock new features and productivity tools. To effectively compare SIP to VoIP, it's best to examine how SIP can enhance VoIP into a multimedia communications experience compared to voice-only internet phone service.
VoIP with SIP Pros
- Offers the potential for immediate cost savings on business applications by allowing companies to consolidate technologies into Unified Communications.
- Provides failover to employee mobile devices if data connectivity is lost.
- Can provide extreme flexibility in pricing by allowing businesses to purchase add-on features and lines by need.
- Includes user-friendly administrative tools for adding lines and features.
- Can seamlessly integrate with cloud applications for Unified Communications implementations.
- May offer built-in integration with common business applications and software for enhanced productivity.
- Could be integrated with existing PRI lines to create a hybrid phone system.
VoIP with SIP Cons
- SIP requires sufficient internet bandwidth to support quality service.
- The quality of service offered by SIP providers can vary.
- The features provided by SIP vendors vary, and may not include full Unified Communications offerings.
- SIP over a public internet service, as opposed to dedicated fiber-optic internet service offered by the same vendor as your SIP carrier, could present quality and security risks.
How to Know which is the Best Fit For You
If you're asking whether SIP or VoIP is the better technology, you've likely committed to considering a switch to Internet-based phone systems. However, SIP vs. VoIP isn't a direct comparison. The most useful question to ask is whether voice-only VoIP phone service best serves your business's needs, or if a SIP implementation with Unified Communications tools is a better fit.
For many businesses, VoIP vs. UCaaS is a better comparison than VoIP vs. SIP. Factors that could shape your understanding of whether UCaaS is the right match can include your budget and desire to adopt multimedia communications tools. If your organization is already using collaboration apps or technologies which are a component of Unified Communications, you could have a strong use case for SIP adoption.
SIP enhances basic VoIP capabilities beyond just voice calling by allowing businesses to exchange messages, video, files, and other forms of data over an internet connection. For many companies, moving directly to SIP and Unified Communications can offer cost savings and productivity gains.
It’s not easy to understand your options or evaluate quality when shopping for a new business phone system. To learn how to find a vendor who offers high-value service, download the free eBook: 10 Questions to Ask Before You Buy Phone Service for Your Business.