No. There is no logical reason that you should have to set it up once for each device once the devices share an identity. I used non-networking examples to show what the ideal experience is because our networking sucks. IP is fine, but everything downstream of that is suspect because things keep gravitating back into silos because of spam. The only resilient form of communication is in person conversation. So far. We can and must be able to piggy-back off that. Once we stop accepting that networking has to suck, we can start building applications that ordinary people can use.