Overview#

Loop Start is a signalling Protocol for Land Lines in which a party gets a dial tone by closing (shorting) a DC current loop.

Loop Start, the electrical loop between your telephone and your Telephone exchange is normally open. When you pick up the telephone handset, it causes a circuit to be closed — creating a loop.

Loop Start signaling is normally used POTS (Public Switched Telephone Network) lines and key-switch systems.

More Information#

There might be more information for this subject on one of the following:

• Calling Number Delivery
• Land Line

---

• [#1] - Loop Start - based on information obtained 2019-08-23