The term “SIP Provider” indicates different factors depending on who is using
it. It has its roots in “SIP Trunking”,
which is an assistance offered to organizations that allows them to join their
in-house IP PBX systems to the
outside world .
Without SIP Trunking, devices within a PBX can only talk to other devices
on the same system. ITSP (The Internet Telephony Service Provider) gives
their clients a pipe or a “trunk”, which makes the connection to the PSTN,
thereby considerably helping the accomplishment and efficiency of their PBXs.
