Let $F/\mathbb Q_p$ be a finite extension, and let $I_F=\mathrm{Gal}(\overline F/F^{\mathrm{unr}})\subset\mathrm{Gal}(\overline F/F)$ be the inertia subgroup. > Is there a description of the abelianization $I_F^{\mathrm{ab}}$ known? Letting $F^{\mathrm{tame}}$ be the maximal tamely ramified extension of $F$, we have an abelian extension $F^{\mathrm{tame}}(\mu_{p^\infty})/F^{\mathrm{unr}}$. How much larger is the full maximal abelian extension of $F^\mathrm{unr}$? Also note that a description of the abelianization of the wild inertia $P_F$ is known due to Iwasawa, see [this question][1]. [1]: https://mathoverflow.net/questions/343296/explicit-construction-of-abelian-wild-inertial-extensions-of-maximal-tamely-rami