SLS handling in libss7

I’m wondering how SLS is handled in libss7 and can it be manually defined as far as the default SLS value selection? I’m trying to get an SS7 link to synchronize with the PSTN. Physically, the link is good but it continues to swap between IDLE and NOTALIGNED. All cics are defined and correspond to the PSTN settings, as well as all the point codes. I did send an ss7 unblock linkset 1 command from the CLI just to see what happened with ss7 debugging turned on and noticed my Asterisk box was sending out SLS 9. The PSTN is using SLS 0 as default. Do the SLS values need to be aligned on each side, i.e. Asterisk box and PSTN?

Thanks in advance!