  We analyse the Transit Timing Variation (TTV) measurements of a~system of two
super-Earths detected as Kepler-29, in order to constrain the planets' masses
and orbital parameters. A dynamical analysis of the best-fitting configurations
constrains the masses to be $\sim 6$ and $\sim 5$ Earth masses for the inner
and the outer planets, respectively. The analysis also reveals that the system
is likely locked in the 9:7~mean motion resonance. However, a variety of
orbital architectures regarding eccentricities and the relative orientation of
orbits is permitted by the observations as well as by stability constraints. We
attempt to find configurations preferred by the planet formation scenarios as
an additional, physical constraint. We show that configurations with low
eccentricities and anti-aligned apsidal lines of the orbits are a natural and
most likely outcome of the convergent migration. However, we show that
librations of the critical angles are not necessary for the Kepler-29 system to
be dynamically resonant, and such configurations may be formed on the way of
migration as well. We argue, on the other hand, that aligned configurations
with $e \gtrsim 0.03$ may be not consistent with the migration scenario.
