SIP is the technology used to carry voice calls over a data network. A SIP Trunk is a virtual line based on Voice over IP technology (VoIP) that uses your internet connection to manage incoming and outgoing calls when connected to a local phone system (PBX). These phone lines are “software” based, and not delivered physically but through your internet connection.
In summary, SIP Trunking is a great option for organizations who want to take advantage of VoIP’s features such as unlimited calling and lower costs, but are not yet ready to take their phone system entirely to the cloud. Instead, they only replace the traditional phone lines with VoIP, moving one step toward the cloud.