The maximum communication speed may change depending on the model. For the models compatible with a packet communications charges flat rate service which are connected to a computer, PDA, car navigation device, etc., KDDI limits the maximum communications speed depending on the congestion conditions of the network when transmitting/receiving large amounts of data such as downloading or uploading files or attaching movie files to prevent excessive loads from occurring on the network.
Refer to the "Discount services" page to check discount services on packet communications charges and phones that allow flat fees for data communications via a mobile computer or other devices as well.