char send_buf[1024] = 
{ 
	0x81, 0x01, 0x00, 0x46,		// header
	0x01, 0x02, 0x03, 0xE8,		// TSID
	0x02, 0x06, 0x12, 0x34,		// CMMAC
	0x56, 0x78, 0x9A, 0xBC,		// CMMAC
	0x03, 0x43,					// DBC, len
				0xAB, 0xCD,		// TransactionID
	0x01, 0x01,					// NumberOfFragments, FragmentSequenceNumber
				0x32, 0x20, 	// 50		DSID Encodings
	0x01, 0x03, 0x65, 0x43,		// 50.1		Downstream Service Identifier (DSID)
	0x21, 
		  0x02, 0x01, 0x00,		// 50.2		Downstream Service Identifier Action
	0x04, 0x16,					// 50.4		Multicast Encodings
				0x02, 0x06,		// 50.4.2	Multicast CM Interface Mask bitmap 4FFF00000001
	0x4F, 0xFF, 0x00, 0x00,
	0x00, 0x01, 
				0x03, 0x0C,		// 50.4.3	Multicast Group MAC address Encodings
	0x12, 0x34, 0x56, 0x78,
	0x9A, 0xBC, 0xFE, 0xDC,
	0xBA, 0x98, 0x76, 0x54,
	0x31, 0x1B,					// 49		Receive Channel Configuration (RCC)
				0x01, 0x05,		// 49.1		Receive Channel Profile ID	 0x0010000003 
	0x00, 0x10, 0x00, 0x00,
	0x03, 
		  0x05, 0x12,			// 49.5		Received Channel assigned by CMTS
					  0x01,		// 49.5.1	Receive Channel (RC) Index
	0x07, 0x01, 0x02, 0x03,
	0x04, 0x05, 0x06, 0x07,
	0x04, 0x04, 0x00, 0x0D,		// 49.5.4	Receive Channel Center Frequency
	0x90, 0x38,
				0x05, 0x01,		// 49.5.5	RC Primary DS Channel Indicator
	0x00
};