Hello Dan. Here is the information. For the first core file : (gdb) frame 5 #5 0x4016f889 in UseMediaProxy (msg=0x8106a28, str1=0x0, str2=0x0) at mediaproxy.c:1454 1454 sprintf(info, "from:%.*s,to:%.*s,fromtag:%.*s,totag:%.*s", (gdb) list 1449 } 1450 1451 agent = encodeQuopri(userAgent); 1452 1453 info = pkg_malloc(infolen); 1454 sprintf(info, "from:%.*s,to:%.*s,fromtag:%.*s,totag:%.*s", 1455 fromAddr.len, fromAddr.s, toAddr.len, toAddr.s, 1456 fromTag.len, fromTag.s, toTag.len, toTag.s); 1457 if (isRTPAsymmetric(userAgent)) { 1458 strcat(info, ",asymmetric"); (gdb) print infolen $1 = 149 (gdb) print &info Can't take address of "info" which isn't an lvalue. (gdb) print info $2 = 0x5 <Address 0x5 out of bounds> (gdb) print fromAddr $3 = { s = 0x80c492f &quot;5555847148(a)sipproxy.redvoiss.net&gt;;tag=802df038f5b36902o1\r\nToo1\r\nTo: <sip:0056085603736@sipproxy.redvoiss.net>\r\nCall-ID: adebb0f0-3065dfaa(a)192.168.1.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization"..., len = 32} (gdb) print *fromAddr Structure has no component named operator*. (gdb) print toAddr $4 = { s = 0x80c4972 &quot;0056085603736(a)sipproxy.redvoiss.net&gt;\r\nCall-IDnCall-ID: adebb0f0-3065dfaa(a)192.168.1.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization: Digest username=\"ID_12481\",realm=\"sipproxy.redvoiss.net\",nonce=\"4"..., len = 35} (gdb) print *toAddr Structure has no component named operator*. (gdb) print fromTag $5 = { s = 0x80c4955 "802df038f5b36902o1\r\nTo: <sip:0056085603736@sipproxy.redvoiss.net>\r\nCall-ID: adebb0f0-3065dfaa(a)192.168.1.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization: Digest username=\"ID_12481\",realm=\"si"..., len = 18} (gdb) print *fromTag Structure has no component named operator*. (gdb) print toTag $6 = {s = 0x401773d0 "", len = 0} (gdb) print *toTag Structure has no component named operator*. (gdb) And here for the second : (gdb) (gdb) bt #0 0x42070fa4 in _IO_str_overflow_internal () from /lib/tls/libc.so.6 #1 0x4206fb28 in _IO_default_xsputn_internal () from /lib/tls/libc.so.6 #2 0x4204528a in vfprintf () from /lib/tls/libc.so.6 #3 0x4206432c in vsprintf () from /lib/tls/libc.so.6 #4 0x4204f18d in sprintf () from /lib/tls/libc.so.6 #5 0x4017b889 in UseMediaProxy (msg=0x8107178, str1=0x0, str2=0x0) at mediaproxy.c:1454 #6 0x0804efe2 in do_action (a=0x8105568, msg=0x8107178) at action.c:610 #7 0x0805079c in run_actions (a=0x8105568, msg=0x8105568) at action.c:718 #8 0x0804ef01 in do_action (a=0x8105598, msg=0x8107178) at action.c:600 #9 0x0805079c in run_actions (a=0x8105568, msg=0x8105598) at action.c:718 #10 0x0804ef01 in do_action (a=0x81055c8, msg=0x8107178) at action.c:600 #11 0x0805079c in run_actions (a=0x8105568, msg=0x81055c8) at action.c:718 #12 0x0804ed9f in do_action (a=0x81044b8, msg=0x8107178) at action.c:375 #13 0x0805079c in run_actions (a=0x8105568, msg=0x8107178) at action.c:718 #14 0x0804ef01 in do_action (a=0x8104518, msg=0x8107178) at action.c:600 #15 0x0805079c in run_actions (a=0x8105568, msg=0x8104518) at action.c:718 #16 0x0804ef01 in do_action (a=0x8104e78, msg=0x8107178) at action.c:600 #17 0x0805079c in run_actions (a=0x8105568, msg=0x8104e78) at action.c:718 #18 0x08069449 in receive_msg ( buf=0x80c48a0 "INVITE sip:5503100@sipproxy.redvoiss.net SIP/2.0\r\nVia: SIP/2.0/UDP 192.168.0.2:5060;branch=z9hG4bK-4cd3c2cf;rport\r\nFrom: 5555848177 <sip:5555848177@sipproxy.redvoiss.net>;tag=e9d67edee86d16dbo0\r\nTo: <"..., len=1139, rcv_info=0xbfffe650) at receive.c:165 #19 0x08079e8f in udp_rcv_loop () at udp_server.c:458 #20 0x0805b480 in main_loop () at main.c:1032 #21 0x0805c7ac in main (argc=0, argv=0x4213ad38) at main.c:1568 #22 0x42015574 in __libc_start_main () from /lib/tls/libc.so.6 (gdb) frame 5 #5 0x4017b889 in UseMediaProxy (msg=0x8107178, str1=0x0, str2=0x0) at mediaproxy.c:1454 1454 sprintf(info, "from:%.*s,to:%.*s,fromtag:%.*s,totag:%.*s", (gdb) list 1449 } 1450 1451 agent = encodeQuopri(userAgent); 1452 1453 info = pkg_malloc(infolen); 1454 sprintf(info, "from:%.*s,to:%.*s,fromtag:%.*s,totag:%.*s", 1455 fromAddr.len, fromAddr.s, toAddr.len, toAddr.s, 1456 fromTag.len, fromTag.s, toTag.len, toTag.s); 1457 if (isRTPAsymmetric(userAgent)) { 1458 strcat(info, ",asymmetric"); (gdb) print infolen $1 = 143 (gdb) print &info Can't take address of "info" which isn't an lvalue. (gdb) print fromAddr $2 = { s = 0x80c4929 &quot;5555848177(a)sipproxy.redvoiss.net&gt;;tag=e9d67edee86d16dbo0\r\nToo0\r\nTo: <sip:5503100@sipproxy.redvoiss.net>\r\nCall-ID: e453655a-c1c3028f(a)192.168.0.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization: Dige"..., len = 32} (gdb) print *fromAddr Structure has no component named operator*. (gdb) print toAddr $3 = { s = 0x80c496c &quot;5503100(a)sipproxy.redvoiss.net&gt;\r\nCall-IDnCall-ID: e453655a-c1c3028f(a)192.168.0.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization: Digest username=\"ID_12375\",realm=\"sipproxy.redvoiss.net\",nonce=\"42d2d2f"..., len = 29} (gdb) print *toAddr Structure has no component named operator*. (gdb) print fromTag $4 = { s = 0x80c494f "e9d67edee86d16dbo0\r\nTo: <sip:5503100@sipproxy.redvoiss.net>\r\nCall-ID: e453655a-c1c3028f(a)192.168.0.2\r\nCSeq: 102 INVITE\r\nMax-Forwards: 16\r\nProxy-Authorization: Digest username=\"ID_12375\",realm=\"sipproxy"..., len = 18} (gdb) print *fromTag Structure has no component named operator*. (gdb) print toTag $5 = {s = 0x401833d0 "", len = 0} (gdb) print *toTag Structure has no component named operator*. (gdb) Hope it helps. If you need more information about the core just email me. Thanks Ricardo Martinez