Vehicular communication networks (VCNs) have emerged as a key technology for next-generation wireless networking. DSRC/WAVE as a leading technology for VCN provides a platform for Intelligent Transportation System (ITS) services, as well as multimedia and data services. Some of these services such as active safety and multimedia services have special requirements for QoS provision. However, when providing QoS, the VCN characteristics are the cause for several new issues and challenges, especially when vehicles travel at high speeds of up to 200 km/h. These issues are addressed in the context of roadside networks and vehicular ad hoc (unplanned) networks (VANETs), including vehicle-to-vehicle (V2V) and vehicle-to-roadside (V2R) communications. Accordingly, plenty of solutions for provisioning QoS in VCNs have been classified in regards to VANETs and roadside networks, on the one hand, and to layer-2 and layer-3, on the other hand. Consequently, several QoS solutions, including medium access and routing protocols, are presented and discussed. Additionally, open research issues are discussed, with an objective to spark new research interests in the presented field.