Landline Dropping Calls, Echoing and Static – Possible Outside Line Issue?

For the past few weeks, we’ve been having ongoing issues with my dad’s Xfinity landline. During calls, the line will randomly drop, have a noticeable echo, or become extremely static-filled, making it difficult to hear the other person.

We’ve already tried several troubleshooting steps:

• Reset/restarted the modem multiple times
• Tried the phone using different jacks throughout the house
• Initially thought the problem might be with the phones on the other end, but it is happening with multiple callers

Nothing we’ve tried has corrected the issue, and it seems to be getting more frequent.

At this point, I’m wondering if there could be an issue with the outside line, connection to the house, or Xfinity equipment. Has anyone experienced something similar, and is there a way to have Xfinity check the outside line/signal?

Thanks for any help!