A SIP trunk is a connection that allows for inbound and outbound calls between an on-premise phone system and the public switched telephone network (PSTN) via the use of SIP (a voice over IP / VOIP) protocol. Most modern or IP based PBXs have the capability to accept a SIP trunk. SIP trunks have a larger capacity for concurrent calls compared to an E1 or T1. A SIP Trunk’s capacity is determined by the allocated bandwidth as well as licenses. This means that a SIP Trunk can support more than 30 simultaneous calls if required.
To confirm your on-premise PBX meets the requirements to host a SIP Trunk please liaise with your support staff or contact us here.