UDP tunnel over SSH : almost?

Question

I am trying to set up a UDP tunnel over SSH but it doesn't work.

Machine A is under Windows Machine B is running Linux

I want to connect (voice over IP) from machine A to machine B via UDP with protocol SIP.

1. On machine A I did : socat.exe udp4-listen:5060,reuseaddr,fork tcp:127.0.0.1:10000

2. On machine B I did socat tcp4-listen:10002,reuseaddr,fork UDP:127.0.0.1:5060

3. On machine A I did also : SSH tunnel from machine A, port 10000 to machine B port 10002

But it doesn't seem to work, at least according to a SIP VOIP phone I am trying to use ?

Any suggestion would be welcomed :-)