[Users] 477 or 503 in sl_reply_error()

Hi folks, I am wondering under what circumstances that openser will generate its default "477" error response. I'm still a newbie on the OpenSER software so I hope I am not just missing some configuration issues. It seems like its(the 477 responsecode) is for instance used when transaction layer didnt manage to send the request, and I am a bit puzzled why the 477 responsecode is used. According to the rfc, I believe "408 Timeout" would be more correct on generic transaction timeouts, and on fatal transport errors, like tcp-reset, I believe 503 is the accurate responsecode. Or? Regards Taisto Qvist IP Solutions