Network impairments are unpredictable and highly destructive to the perceptual quality of media content in the IPTV content distribution networks. As a result the existing network QoS based assessment methodologies are not adequate for the IPTV QoE assessment which determines the overall acceptability of a service as perceived by the end user. A discrete perceptual impact evaluation quality assessment framework (DEQA) is introduced in this paper. The proposed framework enables a real-time, non-intrusive assessment service by efficiently recognising and assessing the individual IPTV quality violation events in the distribution network. The discrete perceptual impacts to a media session are aggregated for the overall user level quality evaluation. With its deployment scheme, the DEQA framework also facilitates efficient network diagnosis and QoE management. Recent work on realising the functions of the framework is also presented.