A method performed by an accessory having an input/output interface capable of communicating with a first portable media device and a second portable media device, the method comprising: establishing a connection to the first portable media device over a first communication channel of a first type; transmitting, to the first portable media device over the first communication channel of the first type, information identifying a communication channel of a second type supported by the accessory; transmitting, to the first portable media device over the first communication channel, a command indicating that the accessory is interested in receiving notifications when the first portable media device connects or disconnects with the accessory over the communication channel of the second type; and while the accessory remains connected to the first portable media device over the first communication channel: detecting a connection on the communication channel of the second type; and: if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has been received over the first communication channel, then determining, on the basis that the notification was received, that the accessory is connected to the first portable media device over the communication channel of the second type, otherwise if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has not been received over the first communication channel, then determining, on the basis that no notification was received, that the accessory is connected to the second portable media device over the communication channel of the second type. establishing a connection to the first portable media device over a first communication channel of a first type; transmitting, to the first portable media device over the first communication channel of the first type, information identifying a communication channel of a second type supported by the accessory; transmitting, to the first portable media device over the first communication channel, a command indicating that the accessory is interested in receiving notifications when the first portable media device connects or disconnects with the accessory over the communication channel of the second type; and while the accessory remains connected to the first portable media device over the first communication channel: detecting a connection on the communication channel of the second type; and: if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has been received over the first communication channel, then determining, on the basis that the notification was received, that the accessory is connected to the first portable media device over the communication channel of the second type, otherwise if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has not been received over the first communication channel, then determining, on the basis that no notification was received, that the accessory is connected to the second portable media device over the communication channel of the second type. if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has been received over the first communication channel, then determining, on the basis that the notification was received, that the accessory is connected to the first portable media device over the communication channel of the second type, otherwise if a notification that the first portable media device has connected with the accessory over the communication channel of the second type has not been received over the first communication channel, then determining, on the basis that no notification was received, that the accessory is connected to the second portable media device over the communication channel of the second type.