This might be a solution
mkdir -p /etc/e-smith/templates-custom/etc/yum.conf/
cp /etc/e-smith/templates/etc/yum.conf/10main_installonlypkgs
nano -w /etc/e-smith/templates/etc/yum.conf/10main_installonlypkgs
add a new line with
installonly_limit=0
ctrl+o & ctrl+x
expand-template /etc/yum.conf
signal-event yum-modify
This allowed the system to update to the latest kernel and not remove the dependent kernel for sail, smesailenv or asterisk18 and packages.
Management of old kernels with this in place will have to be done by admin, but that is easier than rebuilding to whole voip system and getting dahdi back in.