[Users] SER with multiple asterisks

Hi, I have one SER and two asterisk boxes. I'm trying to duplicate each register message from the client so it will reach each of the asterisks. I tried the following in my openser.cfg: if ( (is_method("SUBSCRIBE")) || (is_method("REGISTER")) ) { seturi("sip:nobody@10.0.0.1:5060"); append_branch("sip:parallel@10.0.0.2:5060"); if (!t_relay()) { sl_reply_error(); }; exit; } The first asterisk server registers the UA successfully. The second one gives this error: Oct 3 12:55:48 NOTICE[32364]: chan_sip.c:6395 check_auth: stale nonce received from 'sip:1234566@foo.bar' Transmitting (no NAT) to asterisk2:5060: I googled a bit and I understand I cannot fully duplicate a sip message since the nonce cannot be identical. Is there a way to recreate the sip message with another nonce? Is there any other solution to this scenario? Thanks, Adi.