**** I am not a teacher ****
Both the responses of the second person look grammatically correct, but they sound very blunt, and perhaps even impolite (depending on the situation). How about saying something such as -
- Can I call you back (or can you call me back) and see if the connection is any better?
- Can we try a little later (or can we try another time) to see if the connection is any better?
- I don't know if the problem is at my end or your end. Can I call you on another number (or can you call me from another phone)?
Student or Learner