  Studying transversal structure in extragalactic jets is crucial for
understanding their physics. The Japanese led space VLBI project VSOP has
offered arguably the best opportunity for such studies, by reaching baseline
lengths of up to 36,000 km and resolving structures down to an angular size of
0.3 mas at 5 GHz. VSOP observations of the jet in 0836+710 at 1.6 and 5 GHz
have enabled tracing the radial structure of the flow on scales from 2 mas to
200 mas and determining the wavelengths of individual oscillatory modes
responsible for the formation of the structure observed. We conclude that these
modes are produced by Kelvin-Helmholtz instability in a sheared relativistic
flow. Our results point towards the stratification of the jet and the growth of
different modes at different jet radii. We also discuss the implications of the
driving frequency on the physics of the active nucleus of the quasar.
