I'm trying to buid application that uses Iris XMPP together with QCA (http://delta.affinix.com/), but when I compile my application I got following errors.

Build Issues:
undefined reference to 'ntohs@4'
...
...

Compile Output:
../iris/lib/libiris.a(s5b.o):s5b.cpp.text+0xf23d): undefined reference to `ntohs@4'
../iris/lib/libirisnet.a(jdns_mdnsd.o):jdns_mdnsd.c.text+0x108c): undefined reference to `htons@4'
...
...

QCA and Iris compiles without build issues and I have added includepath and libs from Iris as well.

What that undefined reference to ... means?

All replies are welcome.