* The problem with XMPP is that it requires several open ports (5222, 5223, 5269, 5298, 8010) on the client.*
XMPP does not require any open ports on a client.
XMPP does not require any open ports on a client.
source: I'm an ex-cofounder of a now very successful syncing solution startup who uses XMPP and I wrote the initial server and client code.