Re: OT: Telephone hijaaking

Interesting. Callers could determine that one of those schemes was being used, however.

The original dialed the second number when the first rang. when the second call was picked up, the lines were tied together, which answered the first line. Think of it as an early form of call forwarding, done outside of the CO. It has been used by PIs and police departments to intercept phone calls to a location that was under surveillance. This can be done inside a modern CO by reprogramming the ESS to divert the call to another number.

Seen the circuit that ties the lines together - rather simple. The ESS method is "call forwarding" and costs extra. Either method forwards ALL calls and is not selective.

Sure they are, if they use caller ID.

The relay scheme "knows" nothing - only that ringing took place at the start. Call forwarding is a service by the telco and AFAIK there are no options other than "enable" and "disable". Is there some special info i am missing?

forwarded?

There are a lot of things that can be programmed into an ESS for special needs. None are advertised to the general public. if a line can be physically tapped, selected calls can be intercepted and forwarded. The PTSN is no longer a simple Strowger or crossbar mechanical system.