osmo-bsc and msc connection

Hello everyone, we are struggling to set up an 2G network using single bsc and msc components rather than osmo-nitb. We successfully managed to run an 2G-Network with osmo-nitb using an usrp-n210 as trx. Now how is the BSC supposed to connect to the MSC? In an older build of the osmo-bsc and like described in the osmo-msc user manual I was able to setup an cs7 instance using the m3ua via osmo-stp to the msc. But as I'm using the nighlty-packages now there is no longer a way to configure cs7 instances in the BSC and since we are completely new to this project we aren't up to date with all the recent changes. Apologizes for that. We're also struggling to build the osmo-bsc sources. It quits with "bsc_vty.c:313:5: error: implicit declaration of function ‘OSMO_SEC2DAY’". So I guess there is a package missing but I couldn't find out which one it is. TIA Best regards, Ralf