[Serusers] t_replicate and 'Credentials with given realm not found'

Hi, I have been testing 't_replicate' between two sers. serA: 192.168.0.3 serB: 192.168.0.12 serA's 'ser.cfg': .....(snip)..... modparam("auth_db|auth_diameter|group|uri_db|usrloc|registrar", "use_domain", 1) modparam("auth","secret","abcdef") ......(snip)..... if (method=="REGISTER") { # Uncomment this if you want to use digest authentication if (!www_authorize("192.168.0.3", "subscriber")) { www_challenge("192.168.0.3", "0"); break; }; save("location"); # replicate to the backup server if(!src_ip==192.168.0.12){ log(1,"*** REPLICATE REGISTER REQUEST ****\n"); t_replicate("192.168.0.12","5060"); }; break; }; serB's 'ser.cfg': .....(snip).... modparam("auth_db|auth_diameter|group|uri_db|usrloc|registrar", "use_domain", 1) modparam("auth","secret","abcdef") modparam("usrloc","db_mode",1) ....(snip)..... if (method=="REGISTER") { # Uncomment this if you want to use digest authentication if (!www_authorize("192.168.0.12", "subscriber")) { www_challenge("192.168.0.12", "0"); break; }; save("location"); break; }; serA could send "Request: REGISTER sip:192.168.0.3" from 192.168.0.3 to serB(192.168.0.12) by 't_replicate', but serB says: pre_auth(): Credentials with given realm not found as follows; ....(snip)..... 2(9571) SIP Request: 2(9571) method: <REGISTER> 2(9571) uri: <sip:192.168.0.3> 2(9571) version: <SIP/2.0> 2(9571) parse_headers: flags=1 2(9571) Found param type 232, <branch> = <z9hG4bK3dbc.a52cfe51.0>; state=16 2(9571) end of header reached, state=5 2(9571) parse_headers: Via found, flags=1 2(9571) parse_headers: this is the first via 2(9571) After parse_msg... 2(9571) preparing to run routing scripts... 2(9571) parse_headers: flags=128 2(9571) Found param type 232, <branch> = <z9hG4bKd686d524a54b3ed8>; state=16 2(9571) end of header reached, state=5 2(9571) parse_headers: Via found, flags=128 2(9571) parse_headers: this is the second via 2(9571) end of header reached, state=9 2(9571) DEBUG: get_hdr_field: <To> [23]; uri=[sip:114@192.168.0.3] 2(9571) DEBUG: to body [<sip:114@192.168.0.3> ] 2(9571) get_hdr_field: cseq <CSeq>: <101> <REGISTER> 2(9571) DEBUG:maxfwd:is_maxfwd_present: value = 16 2(9571) parse_headers: flags=256 2(9571) DEBUG: get_hdr_body : content_length=0 2(9571) found end of header 2(9571) find_first_route: No Route headers found 2(9571) loose_route: There is no Route HF 2(9571) grep_sock_info - checking if host==us: 11==12 && [192.168.0.3] == [192.168.0.12] 2(9571) grep_sock_info - checking if port 5060 matches port 5060 2(9571) grep_sock_info - checking if host==us: 11==12 && [192.168.0.3] == [192.168.0.12] 2(9571) grep_sock_info - checking if port 5060 matches port 5060 2(9571) grep_sock_info - checking if host==us: 11==12 && [192.168.0.3] == [192.168.0.12] 2(9571) grep_sock_info - checking if port 5060 matches port 5060 2(9571) grep_sock_info - checking if host==us: 11==12 && [192.168.0.3] == [192.168.0.12] 2(9571) grep_sock_info - checking if port 5060 matches port 5060 2(9571) parse_headers: flags=4096 2(9571) found end of header 2(9571) pre_auth(): Credentials with given realm not found 2(9571) build_auth_hf(): 'WWW-Authenticate: Digest realm="192.168.0.12", nonce="42dc3cad3841a0086c78df73d97f1671b9054aab" ' 2(9571) parse_headers: flags=-1 2(9571) check_via_address(192.168.0.3, 192.168.0.3, 0) 2(9571) DEBUG:destroy_avp_list: destroying list (nil) 2(9571) receive_msg: cleaning up -------- I cannot replicate serA's UA to serB. How should I do ? Regards, Zen