What is a loop?

Loops are a pair of phone numbers, usually consecutive, like 836-9998 and 836-9999. They are used by the phone company for testing. What good do loops do us? Well, they are cool in a few ways. Here is a simple use of loops. Each loop has two ends, a 'high' end, and a 'low' end. One end gives a (usually) constant, loud tone when it is called. The other end is silent. Loops don't usually ring either. When BOTH ends are called, the people that called each end can talk through the loop. Some loops are voice filtered and won't pass anything but a constant tone; these aren't much use to you. Here's what you can use working loops for: billing phone calls! First, call the end that gives the loud tone. Then if the operator or someone calls the other end, the tone will go quiet. Act like the phone just rang and you answered it ... say "Hello", "Allo", "Chow", "Yo", or what the fuck ever. The operator thinks that she just called you, and that's it! Now the phone bill will go to the loop, and your local RBOC will get the bill! Use this technique in moderation, or the loop may go down. Loops are probably most useful when you want to talk to someone to whom you don't want to give your phone number.

Excerpted from: ToneLoc v0.99 User Manual by Minor Threat & Mucho Maas

What is a loop in my area?

Many (if not most) of these loops are no longer functional. If you are local to any of these loops, please try them out an e-mail me the results of your research.

NPA High Low Notes
310 455-0002 455-????  
310 546-0002 546-????  
312 262-9902 262-9903 Very odd sound
313 224-9996 224-9997  
313 225-9996 225-9997  
313 237-9996 237-9997  
313 256-9996 256-9997  
313 272-9996 272-9997  
313 273-9996 273-9997  
313 292-9996 292-9997  
313 369-9996 369-9997  
313 388-9996 388-9997  
313 465-9996 465-9997  
313 471-9996 471-9997  
313 556-9996 556-9997  
313 561-9996 561-9997  
313 561-9996 561-9996  
313 569-9996 569-9996  
313 577-9996 577-9996  
313 621-9996 621-9997  
313 722-9996 722-9997  
313 822-9996 822-9997  
313 833-9996 833-9997  
313 871-9996 871-9997  
313 875-9996 875-9997  
313 886-9996 886-9997  
313 963-9996 963-9997  
315 695-9995 695-9996  
323 626-1118 626-1119  
406 225-9902 225-9903  
408 238-0044 238-0045  
517 423-9996 423-9997  
517 563-9996 563-9997  
517 663-9996 663-????  
517 851-9996 851-9997  
562 369-1118 369-1119  
613 966-1111    
619 364-1118 364-1119  
703 591-9994    
713 455-1499 455-1799  
713 462-1499 462-1799  
713 469-1499 469-1799  
713 482-1499 482-1799  
713 526-1499 526-1799  
713 682-1499 976-1799  
713 988-1499 988-1799  
714 629-1118 629-1119  
719 598-0009 598-0010  
909 661-1118 661-1119  




Bookmark What is a loop?

Free White Papers on Telephony


Telephony Magazine

Latest Blog Posts


Copyright 2008 Tech-FAQ. All rights reserved.