A large number of studies have been conducted to evaluate the benefits of using layered video coding schemes as a means to improve the robustness of video communications systems. In this article, we study a frame-aware layering scheme for the transport of DCT-based video over packet switched networks. Under this scheme, the relevance of the different elements of the video sequence is taken into account in order to compose the encoded video sequence. We conduct a detailed study over a large set of video streams encoded using the MPEG-2 video standard. Our results show that it is possible to reduce the video traffic while maintaining an acceptable video quality.