it’s so simple. but exceptional cases was that the office was in Regus they are supporting internet, place and phones.
but we needed leased line to communicate with SAMSUNG Network and there were Avaya phones also that were registered with head office.
Avaya phones were easy to configure just changed IP, MASK, GW and Voice Vlan.
to connect with leased line, I installed a router and a switch. that was all.
the problem was that installing line was too delayed and the IP information from ISP were wrong, I couldn’t go back to Rio de Janeiro to just change the ip address.
So We discussed it with ISP worker for a couple of days to ask them to change their IP address. and it was well done