106 is dialed the number may be prestored in memory or entered by a user of computer 102 when a call is routed through pstn 101 to central office 107 a ring back tone is generated which is transmitted back to computer 102 the ring back tone is received at operational block 203 and transferred to a quality measurement algorithm at block 204 the quality measurement algorithm utilizes signal parameters such as signal to noise ratio amplitude etc and outputs a value indicative of the overall quality of the line the value may be in the form of a maximum available bit rate algorithms for calculating the maximum available bit rate are known in the art and have been used for quite some time at decision point 205 the algorithm determines whether or not the available bit rate is acceptable the criteria for making such determination is preferably based upon a prestored desirable bit rate which has been entered by the user importantly the prestored bit rate is usually larger than the minimum bit rate which may be utilized by computers 102 and 106 accordingly while computers 102 and 106 may in fact be able to transfer data between them at some minimum bit rate over the telephone lines decision point 205 will nonetheless decide that the bit rate is unacceptable if it is too low in this manner the system will simply place another telephone call and get a higher quality connection with.