Partial writes do not work over UDP; by design. As to whether or not you can use a packet as big as 16K, in depends on the "path MTU" -- what's the maximum transmission size between you and the destination, along the communication path. You'll have to make your packets smaller then that. This isn't, really, an openssl issue.
-- Principal Security Engineer Akamai Technologies, Cambridge MA IM: [email protected] Twitter: RichSalz
