To a question of an intersymbol interference in a digital link
The concept an intersymbol interference (MSI) is defined. Modern ideas of an intersymbol interference are described. Statements about conditions when the intersymbol interference in the communication line is equal to zero are provided. Modeling of eye diagrams of channel with low pass filters such as Butterworth and Gauss, at different signal to noise ratios, is carried out in program Vissim Comm 6. Some recommendations for reduction of an intersymbol interference in a communication channel are made.