A softphone is a software application that turns a computer, tablet, mobile phone or web browser into a business phone. It registers with the organization’s phone system, uses the user’s extension and direct number, and makes and receives calls over the internet or a private network using Voice over IP. Softphones are usually provided by the phone system or UCaaS vendor, either as a standalone app or built into a broader app that also includes meetings and messaging.
At a glance
- A softphone is an app that does the job of a desk phone, using a headset or the device’s own audio.
- It connects to a phone system (on premises, hosted or UCaaS) and usually uses the same extension and number as the user’s desk phone, if any.
- Mobile softphone apps let staff use their business number on a personal or company phone.
- Call quality depends on the device, the headset and the network the user is on.
- Emergency calling needs extra planning, because the user’s location can change.
What problem it solves
Desk phones tie a business number to a desk. When people work from home, travel, or split time across offices, calls to their desk go unanswered or are forwarded to personal mobiles, which exposes personal numbers to customers and loses call records. Buying and managing desk phones for every user also adds cost.
A softphone puts the business phone wherever the user is. Calls to their extension ring on their laptop or mobile app, outbound calls show the company’s caller ID, and the organization keeps call routing, recording and reporting in one system. For staff who mainly work at a computer, a softphone and headset can replace a desk phone altogether.
How it works
Registration. The app signs in to the phone system, often using the user’s company login, and registers as one of the user’s devices. Many systems ring all of a user’s devices at once, so a call can be answered on the desk phone, laptop or mobile.
Signaling and media. Most softphones use Session Initiation Protocol (SIP) or a vendor’s own protocol to set up calls, and send audio as VoIP packets. Browser-based softphones typically use WebRTC, so there is nothing to install.
Features. Depending on the platform, softphones offer transfers, hold, conferencing, voicemail, call history, presence and sometimes video and chat. In UCaaS products, calling is usually one tab in an app that also handles meetings and messaging. With hosted PBX services, the softphone may be a separate calling app.
Devices. Softphones run on company or personal devices. On personal devices, a bring your own device (BYOD) policy should set out what the company can manage and what happens to call data if the person leaves.
Emergency calls. Because the device moves, the system needs the user’s dispatchable location, detected automatically from the network or confirmed by the user, so E911 calls reach the right responders. How this works varies by provider and country.
When it matters for buyers
- When moving to UCaaS or a hosted PBX, since softphones may reduce how many desk phones you buy.
- When staff work from home or travel, and need their business identity on calls.
- When mobile phone policies are under review, because a mobile softphone can separate business and personal calling on one device.
- When call quality complaints come from remote workers, which usually traces to home networks or headsets.
- When planning emergency calling for users who are not at a fixed desk.
Questions to ask vendors
- Which platforms do your softphone apps support (Windows, macOS, iOS, Android, browser), and are they included in the per-user price?
- Can a user be signed in on several devices at once, and how are calls delivered to each?
- How do your mobile apps handle incoming calls when the app is in the background or the phone is locked?
- How do you collect or detect location for 911 calls from softphones?
- Which headsets do you certify or recommend?
- What call quality data can administrators see for softphone users?
- What controls do we have over personal devices, and what happens to call records when someone leaves?
How it differs from WebRTC
WebRTC is an open technology that lets web browsers and apps send real-time audio and video. A softphone is a product: an app that acts as a business phone. Many browser-based softphones are built on WebRTC, while installed desktop and mobile softphones may use SIP or a vendor’s own protocol. Choosing a softphone means comparing features, management and quality, not the underlying technology.
To see how softphones fit into a broader cloud calling decision, visit our Unified Communications as a Service solution page.