Systems and methods for handling buffer overflows and underflows in a software defined radio are presented. A communications system comprises one or more radio head interface modules and a call processing software module. The radio head interface modules are adapted to communicate with the call processing software module. The call processing software module performs modulation and demodulation of voice and data streams and transmits complex RF data samples to the radio head interface modules. A first radio head interface module is adapted to create zero value data samples when complex RF data samples are not received from the call processing software module at an expected data sample rate. The first radio head interface module is further adapted to count zero value data samples created and discard a number of complex RF data samples based on the number of zero value data samples counted by the first radio head interface module.