Normally should take between 3-15 seconds to disconnect a call. If trouble persists, disconnect all phones except for one and see if it still happens. If it doesn't happen anymore the trouble is with one of the phones you unhooked. If you are still having the trouble see if you get your dialtone back after 15 seconds. If not, call repair service at your local phone company to have your line tested to make sure nothing is wrong. There are a number of issues that could cause this type of problem that an electronic line test might find out.