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Dial Tone Distribution


The Division of Network Systems and Telecommunications - CIT Telecommunications Branch utilizes a centralized 5ESS Switch located at the Building 10 facility. CIT Telecommunications is responsible for providing and maintaining dial tone for over 60,000 phones through voice or data phones at the National Institute of Health, Bethesda, Maryland. Our goal is to meet the constant communications needs for NIH employees in this fast paced and often critical research environment.

Other areas managed by CIT Telecommunications in which dial tone connectivity and maintenance is provided includes NIH Institutes in the Washington-Metropolitan area, Frederick and Baltimore Maryland locations, Research Triangle, NC, Hamilton, Montana, Jackson, Mississippi, and Phoenix, Arizona.

The CIT Telecommunications Branch primary goal is to insure that every time a NIH employee picks up their telephone to begin communications, they have clear and uninterrupted dial tone. Special care is provided to those Institutes and NIH services that require dial tone to provide and maintain critical care needs or emergency services.

The ‘Do Not Touch’ Phone Lines

A phone line designated as a “DO NOT TOUCH” is a line that has been defined as being essential to public safety and the National Institutes Health’s ability to provide critical health care. Any National Institutes of Health IC may designate a telephone number as one that should not be changed, disconnected or moved without written authorization by the line owner or other authorized individuals.

Continuity of Operations Plan (COOP)

CIT Telecommunications provides uninterrupted dial tone to the National Institutes of Health Continuity of Operations Plan facility. These areas are designated as Emergency Operations Command Posts used in emergency situations supporting the National Institutes of Health campus and surrounding facilities.

Elevator Phones

There are more than 200 Elevator Phones located throughout the NIH community providing security in case of emergency. These phones link directly to the Operator Services Call Center Operation to provide immediate attention in both critical and non-critical situations. For more information on Elevator Phones Click here

Security Phones and Blue Light Phones

Security Phones are located at designated entrances and loading docks of the National Institutes of Health (NIH) buildings, both on and off campus locations. The purpose of these phones is to enhance and maintain security measures when providing access into buildings before and after working hours.

Blue Light phones are located in NIH parking lots and garages and throughout the NIH campus providing a direct voice link 24/7 to NIH Police, Fire and Rescue Services . For more information on Blue Light Phones Click here

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This page last reviewed: September 12, 2008