what is difference between NM-HDV2-1T1/E1 and VWIC-1MFT-E1 which is an option card in NM-HDV2-1T1/E11 NM-HDV2-1T1/E1 with 1 VWIC-1MFT-E1 will be 2 E1, the two E1 will be the same?I see 2610XM WIC slot also can insert one VWIC-1MFT-E1,so with 2610XM I...