The Laser Interferometer Space Antenna (LISA) is a European space mission that will be able to detect gravitational wave (GW) radiation in the yet unexplored low frequency end of the GW spectrum. The most prominent sources emitting at mHz frequencies are millions of compact galactic binaries forming the galactic background noise (GBN). In order to successfully detect GW signals the design of LISA requires the interspacecraft distances to be determined with meter accuracies. Time-delay interferometric ranging (TDIR) is one of the proposed ranging methods. The aim of this thesis is to examine the impact of the GBN on the performance of TDIR. Therefore the GBN is modeled based on the result of a one year simulation and a TDIR algorithm is implemented in order to evaluate the increase in the uncertainties of the arm length measurements. This work shows that the response of LISA to the GBN in terms of fractional frequency fluctuations follows a Gaussian process with an amplitude spectral density that can be easily parameterized. Due to the response at low frequencies the impact on TDIR is found to be negligible. Instrumental noises that limit the accuracy of the ranging measurements are far more relevant. Their influence has to be thoroughly characterized in future work.