Not sure why the question is being asked. If you mean in the office, the answer is "maybe." Most of us in an office setting now can use our computer to make and receive telephone calls so many of the offices no longer have a desk phone.
As to mobile phone, as others have noted, if your role is identified as needing a mobile device, your manager can approve reimbursement for a Bring-Your-Own-Device ("BYOD") where Oxy will reimburse you for a portion of your costs. But is not a given and in return for participating in a BYOD program, you agree to have certain software and apps installed, that include the ability of Oxy to "wipe" your phone (not exactly sure what they can or cannot wipe, so I keep all my pictures and personal documents stored in my own personal cloud storage).