Sabrina,
I hoked up our phone line just last night, after much baf and forth with eircom. the line had a dial tone when I pluged my phone into the socket and I dialed (i think!?) 199000 or 19000 and got an automated number for the line. Then I called eircom to connect the line, gave them this number so they could trace me easily (although they had our apartment number wrong?), I was told there was no connection fee. I'm in a new build, the socket was already installed by eircom.
Hope this helps.
ad