So just yesterday an Infinity Comcast internet technician went to one of my units to hook up a new roommate's modem in his room or something, and informed my tenants that he was seeing speed/quality issues while testing the cables. He checked the ports where the cables came into the building and (according to the cable guy) they are functioning perfectly, which means (according to the cable guy) that the problem is somewhere in the cabling inside the house. The tenants want to have Comcast come out and fix it - whatever "fix" means in this case, which is not entirely clear to me. Sounds like they are talking rewiring or running cables through the walls or something. They are good low maintenence tenants who do a good job of taking care of the place. Both first and second floor cables run into the building on the first floor, so a technician will likely need access to both units in the building. I was planning on speaking to Comcast about it tomorrow and getting more information if possible. Including possible costs. Generally though, when it comes to cable lines or rewiring who is the one responsible? The lease does not have either internet or cable checked off where it says "rent shall include the following" and has other things like water, lawn care, and snow removal that are checked off with respect to the landlord's responsibility. What is the preferred method for handling this?

Olde coax cables may work ok for tv service, but cause problems with higher speed services such as internet or some streaming services.

Unfortunately, the only solution is to run new cables presuming they are older. Usually an electrician can do this cheaper than the cable company. Also, I wouldn't trust the cable company drilling holes in my house.

Your responsibility to insure it is working. Make sure you do not allow a tenant to run any cable inside the unit. They are permitted to connect to jacks provided and no where else. You will need to inspect regularly to insure they have not stapled cables around your base boards causing damage.