VoIP systems, sometimes called cloud PBXes, can manage all your voice communications from a central web console no matter how many extensions you've got, where your employees are located, or even what devices they're using. Most systems also offer features like video conferencing and team collaboration. Put all that together with subscription-based pricing that's generally much cheaper than an old-fashioned, on-premises PBX, and VoIP remains one of the best communications investments any business can make, especially during the pandemic.
But it can also handle other functions, including session setup (initiating a call at the target endpoint—the phone you're calling), presence management (giving an indicator of whether a user is "available," "away," etc.), location management (target registration), call monitoring, and more. Despite all that capability, SIP is simple compared to other VoIP protocols primarily because it's text-based and built on an easy request/response model that's similar in many ways to both HTTP and SMTP. Yet, it's still capable of handling the most complex operations performed by business-grade PBXes.

Enabling your employees to converse, meet, and discuss projects live is what you need to grow your business. Your business phone system is your competitive advantage.
31. Hi, this is [your name] at [your company]. If you are calling for [include reason] please visit our [website, social media handle, etc.], contact [name and title of colleague and phone number] or send me an email at [insert email address]. For other inquiries, leave a brief message and your name and number and I will call you back by [timeframe].