Post #4377458

@steve@mastodon.nexusuk.org @revk@toot.me.uk More and more digits wouldn't apply on electro-mechanical exchanges either since you wouldn't be able to back trace until the call had connected. That required engineer(s) to physically check each switch working backwards from the called sub's final selector (in the case of Strowger) to the calling sub's line equipment. For a call to a normal number the trace would need to be done while still connected (controlled by the caller) but most call traces were for 999 calls and if I recall correctly (no pun intended) the emergency operators could, for obvious reasons, hold the call up even if the caller cleared down.