UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 Certification and Notice of Termination of Registration under Section 12(g) of the Securities Exchange Act of 1934 or Suspension of Duty to File Reports Under Sections 13 and 15(d) of the Securities Exchange Act of 1934. Commission File Numbers: 0-23263 and 333-86109 Excel Switching Corporation ----------------------------------------------------- (Exact name of registrant as specified in its charter) 255 Independence Drive, Hyannis, MA 02601 ------------------------------------------------------ (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices) COMMON SHARES, $.01 par value ----------------------------------------------------- (Title of each class of securities covered by this Form) None - ------------------------------------------------------------------------------- (Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains) Please place an X in the box(es) to designate the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports: Rule 12g-4(a)(1)(i) |X| Rule 12h-3(b)(1)(ii) | | Rule 12g-4(a)(1)(ii) | | Rule 12h-3(b)(2)(i) | | Rule 12g-4(a)(2)(i) | | Rule 12h-3(b)(2)(ii) | | Rule 12g-4(a)(2)(ii) | | Rule 15d-6 | | Rule 12h-3(b)(1)(i) |X| Approximate number of holders of record as of the certification or notice date: 1 Pursuant to the requirements of the Securities Exchange Act of 1934, Excel Switching Corporation has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person. Date: November 12, 1999 By: /s/ Jean F. Rankin ------------------------------------------ Name: Jean F. Rankin Title: Vice President