// content type
#define CTYPE_APP_SDP		0
#define CTYPE_MSG_SIPFRAG	1
#define CTYPE_APP_DTMF		2
#define CTYPE_APP_SMS		3	// simple-message_summary
#define CTYPE_TEXT_PLAIN	4
#define CTYPE_TEXT_HTML		5
#define CTYPE_MULTIPART		6
#define CTYPE_UNKNOWN		255

// Event type
#define EVENT_TYPE_REFER		0
#define EVENT_TYPE_MSG_SUMMARY	1
#define EVENT_CHECK_SYNC		2
#define EVENT_TYPE_UNKNOWN		255

#define TOKEN_TAG_LEN		4
#define TOKEN_SIP_LEN		4

