The present invention is directed to providing compatibility between teletype telephone devices. In particular, embodiments of the present invention alter the described duration of tones used to encode individual characters generated in accordance with a first protocol so that the description complies with a second protocol. Other embodiments of the present invention, in response to receiving a description of tones expressed according to a first protocol, generate tones in accordance with a second protocol. Where a protocol used by a sending device is capable of transmitting text at higher rates than a protocol used by a receiving device, the descriptions of the tones may be buffered. Embodiments of the present invention may additionally provide feedback to the users of transmitting files when data is buffered, to indicate that the transmission is in progress.