Existing Audio Deepfake Detection (ADD) systems often struggle to generalise effectively due to the significantly degraded audio quality caused by audio codec compression and channel transmission effects in real-world communication scenarios. To address this challenge, we developed a rigorous benchmark to evaluate ADD system performance under such scenarios. We introduced ADD-C, a new test dataset to evaluate the robustness of ADD systems under diverse communication conditions, including different combinations of audio codecs for compression and Packet Loss Rates (PLR). Benchmarking on three baseline ADD models with the ADD-C dataset demonstrated a significant decline in robustness under such conditions. A novel data augmentation strategy was proposed to improve the robustness of ADD systems. Experimental results demonstrated that the proposed approach increases the performance of ADD systems significantly with the proposed ADD-C dataset. Our benchmark can assist future efforts towards building practical and robustly generalisable ADD systems.