Personal take: suck it up, Somalia; if the population of Somaliland has effective control of the region, and desires it to be independent, then there isn't much that you could (or should) do. And from that, if both Somaliland and Ethiopia reach an amicable agreement over the ports, so be it.
Also, let us drop all that babble about territorial integrity. Even if you believe in this sort of political superstition, Somalia's territorial integrity went kaboom in 1991.