Brainstorm Networks S-1 IPO registration

Exhibit 12.1

RCN CORPORATION AND SUBSIDIARIES

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(In Thousands)

	December 21 - December 31, 2004			January 1 - December 20, 2004			FOR THE YEAR ENDED DECEMBER 31,												For the Quarter Ended March 31,
							2003			2002			2001			2000			2005			2004
	(Successor)			(Predecessor)			(Predecessor)												(Successor)			(Predecessor)
Income (loss) from continuing operations, before income taxes and reorganizational costs	$	(3,688	)	$	(260,381	)	$	(486,946	)	$	(1,450,622	)	$	(1,173,088	)	$	(779,474	)	$	(29,079	)	$	(98,052	)
Interest expense		888			96,702			180,206			167,663			196,681			223,383			10,233			42,429
Interest component of lease rental expense		—			2,881			2,821			3,581			4,964			4,170			314			619
Income as adjusted	$	(2,800	)	$	(160,798	)	$	(303,919	)	$	(1,279,379	)	$	(971,443	)	$	(551,921	)	$	(18,532	)	$	(55,004	)
FIXED CHARGES
Interest Expense	$	888		$	96,702		$	180,206		$	167,663		$	196,681		$	223,383		$	10,547		$	42,429
Interest component of lease rental expense		—			2,881		$	2,821			3,581			4,964			4,170			314			619
Total fixed charges	$	888		$	99,583		$	183,027		$	171,244		$	201,645		$	227,553		$	10,547		$	43,048
Ratio of Earnings to Fixed Charges		—			—			—			—			—			—			—			—
Deficit of earnings to fixed charges	$	(3,688	)	$	(260,381	)	$	(486,946	)	$	(1,450,622	)	$	(1,173,088	)	$	(779,474	)	$	(29,079	)	$	(98,052	)