SIP trunking - Computer Definition
Establishing a voice over IP (VoIP) account with a SIP telephony provider. SIP is the most widely used method for connecting IP phones and PBXs to the public telephone system (PSTN), and SIP providers route calls to the IP address of their customers and vice versa. Based on the service level agreement, the SIP provider configures a specific number of concurrent phone call sessions (SIP trunks) for each of its customers. See SIP provider, VoIP and ITSP.