i am trying to make IMA bundle with E1 channel. i am using 2VWic-2MFT T1/E1 card on 3845.my old router is 3640 with NM-ATM card. and it has a impedance 120-ohm configured on every ATM interface. now when i tried to configure my new Interface ATM 0/0/0 with impedance 120-ohm, its give me error, there is no impedance command on that interface. how could i setup this command on my atm 0/0/0 interface.