Structure msg_start

struct msg_start {
    int type;                        /* Type of the Message - Request/Response */
    union {
        struct {
            str method;              /* Method string */
            str uri;                 /* Request URI */
            str version;             /* SIP version */
            int method_value;        /* Parsed method */
        } request;
	struct {
            str version;             /* SIP version */
            str status;              /* Reply status */
            str reason;              /* Reply reason phrase */
            unsigned int statuscode; /* Status code */
        } reply;
    }u;
};