A method includes sending, by a first device to a second device, a first request identifying a first caller, identifying a callee, and comprising indication information of a first service; running, by the second device in response to the first request, a first instance in a first sandbox; sending, by a third device to the second device, a second request identifying a second caller, identifying the callee, and comprising indication information of a second service; and running, by the second device in response to the second request, a second instance in a second sandbox, where the second instance is of the callee and provides the second service to the second caller, and where the second sandbox is different from the first sandbox.