  Our previous studies revealed a good kinematic model for the jet of Cygnus A,
but the counter-jet speed is still not well constrained. The central engine and
part of the counter-jet of Cyg A are likely to be obscured by free-free
absorbing material, presumably a thick torus. At mm-wavelengths, the absorber
becomes optically thin, which provides a more detailed view into the inner
nuclear region. Knowing the speed of jet and counter-jet and their flux density
ratio allows to determine the jet Lorentz factors and orientation. Therefore we
started to monitor Cyg A with global VLBI at 43GHz in Oct. 2007. Our first
epoch reveals a previously unseen gap between both jets. This could be either a
sign for a new counter-jet component that is slowly separating or we start to
see the very inner acceleration region of the jet which is not efficiently
radiating at radio wavelengths. Further more the image shows transversely
resolved jet structures at distances beyond ~0.5pc which facilitate more
detailed investigations addressing jet stratification. Analysis of the resolved
jet structure shows that the initially wide jet (opening angle ~10deg)
collimates within the first parsec into a edge-brightened jet with an opening
angle of ~3deg.
