I've recently been loking into SIP trunks and VoIP tecnology. However, I don't fully understand what is the role of SIP trunks is.
To my understanding, VoIP technology works by sending pakets over the internet, and with a VoIP service porvider, the parkets are sent to their destinations. In case the destination is a landline number, a sip trunk must be used. However, i dont get what part does it play. Is it a software component? If so, is it something the business using VoIP must implement? Is it something only the business pays and the provideer conects voice calls to the PTSN? Or i dont get if it is a phyiscal component, that is necessary to conect the business to the VoIP provide.
Any insight in this matter is greatly apreciated.
I've recently been loking into SIP trunks and VoIP tecnology. However, I don't fully understand what is the role of SIP trunks is.
It is a common and recurring problem with SIP trunking, you are not alone.
Your understanding of VOIP is correct but this will not help you to understand trunks.
Trunk is a concept inherited of TDM telecom network, it was in the beginning a certain number of twisted copper wire pairs molded in one big cable and latter with PCM introduction any cable that multiplex communication. So you have trunk between ethernet-switches or between enterprise PBX or between carriers (telco service provider) and so on ...
In you question, you are talking about SIP Public Trunking, this is the same commercial offer than the older TDM ISDN connection so basically it is a ISDN replacement with the same basic service.
In term of SIP, the trunk provides a point of registration (REGISTRAR), authentication, billing and basic call features ; in summary a kind of SIP edge proxy/registrar