What caster level do you need to craft a ring of protection +5

I had always assumed that there was a similar requirement to crearing higher tiers of rings of protection (and magic items in general), just like you need to be at least three times the enhancement bonus in caster level for magic weapon- and armor enhancement.

However a player pointed out that the rules do not say so and frankly I haven’t found anything contradicting in the DMG. Is it actually the case that you could theoretically forge a ring of protection +5 at caster level 5th given that you have a high enough level to get the approptiate feat – or am I missing something?