Issue with home phone not working with fax machine

I have a Brother MFC and I tried to send out a fax to several 1 800 #s and it doesn't send even though I hear the whistling sound from the fax machine. The fax then disconnects and the fax screen says COM error 2001 or 2006. A printout says NG: POOR LINE CONDITION. Is the MFC the problem or my wireless home phone adapter the problem?