If a punchdown seems like overkill, use the "jellybeans" (telephone tap/splice connectors). I'm assuming there is some sort of weatherproof box where the cable & phone lines exit the house.
Splice all the lines together at the outside termination point & use the line from the outside to the jack near the modem as the 'feed' to the rest of the lines.
Check with the alarm company about any specific requirements they may have. I wouldn't worry about the box on the outside -- any thief that would get in the box would just cut the cable if the box wasn't there.
Splice all the lines together at the outside termination point & use the line from the outside to the jack near the modem as the 'feed' to the rest of the lines.
Check with the alarm company about any specific requirements they may have. I wouldn't worry about the box on the outside -- any thief that would get in the box would just cut the cable if the box wasn't there.