Direct-Dial Tie Lines

Use these MIT direct-dial numbers to avoid message-unit or toll charges when calling the institutions listed below. If your phone is restricted to on-campus calling, you must use the tie lines to call these institutions. Enter the three- or four- digit code plus the appropriate extension number.

To call...	If extension is known, press...	*If extension is unknown, press...**	Main phone number
American Academy of Arts and Sciences	195 + three digits	195 + 000	617.576.5000
Bates Linear Accelerator	3 + four digits	3-9200	617.253.9200
Draper Laboratory	182 + five digits	182 + 0-0000	617.258.1000
Endicott House	3 + four digits	3-5211, 3-5212, 3-5213	781.326.5151
Harvard Business School	186 + five digits	186 + 5-5000	617.495.6000
Harvard Medical School	1862 + four digits	186 + 5-5000	617.495.1000
Harvard University	186 + five digits	186 + 5-5000	617.495.1000
Lincoln Laboratory, Haystack Observatory, Millstone Radar Site	181 + four digits	181 + 0000 (Off hours: 181 + 2444)	781.981.5500
Massachusetts General Hospital	1936 + four digits	1936 + 2090	617.726.2000
Massachusetts General Hospital, Ellison Bldg.	1934 + four digits	1936 + 2090	617.726.2000
Mount Auburn Hospital	194 + four digits	194 + 0111	617.492.3500
Radcliffe College	186 + five digits	186 + 5-5000	617.495.8000
Wellesley College	187 + four digits	187 + 1000	781.283.1000
Woods Hole Oceanographic Institution	188 + four digits	188 + 1000	508.548.1400
*Ask the operator for the extension number, then hang up and enter the tie-line number plus the extension

Telephone Support Resources

Telephone Support and Repairs
(Traditional and MITvoip phones)
Email: telephone-help@mit.edu
Phone: 617.253.4357

Traditional Phone Moves/Changes
(For use by AOs/DLC administrators)
Email: telephone-help@mit.edu
Phone: 617.253.3670

On-site Instruction from Client Support Representatives

Telephone Operator Services

Direct-Dial Tie Lines

Telephone Support Resources

Related Links