Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 166, § 13

A person owning, controlling or operating a telephone exchange or service in the commonwealth shall, upon application of a telegraph company, furnish such company with the use of telephones and telephone service, and connection with his exchanges, with the subscribers thereto, and with his telephone service, without discrimination between telegraph companies as to such connection, service or use of instruments furnished or charges therefor for the same class of service. For the purposes of sections 13 to 15D, inclusive, the word “person” or “company” shall include a municipal lighting plant or cooperative which operates a telecommunications system pursuant to section 47E of chapter 164.