GNURadio GFSK modulation/demodulation through udp sockets

I have a little problem. Im trying to run a very basic GNU Radio program through UDP sockets. However, when I add GFSK modulator and demodulator in between, the program output rubbish. I tried to add packet encoder/decoder without any success. Could any GNURadio guru tell me whats im doing wrong ? Thanks in advance.

Solution

There's no framing, which means that the first symbol you send isn't necessarily the first symbol to get decoded successfully, so you got a bit shift in your whole bitstream.

Also, you use different sensitivity in your Mod and Demod.