Large size UDP Packet

[Dmitry Kurdumov]

I'm trying to send UDP packet those size is lager then MTU ( 1500 for my
Ethernet )
but socket doesn't send it. In udp_usrreq.c  varibale udp_sendspace 
initialized by 9216. I'm specially try to send smaller size packet
( for example 6000 ) but it result in fail. May be UDP packet can't be
fragmented  into several IP's?
What should I set to properties of UDP socket?

target: SH4

Will be glad to any help. Dmitry.