Integration of XMII and ECC

[buvanesh]

Hi all,
      I am trying to integrate XMI 11.5 and SAP ECC and facing problem in selecting whether to use BAPI or IDOC . The Batch and inventory data has to be transferred from SAP ECC to XMII and the data will be of large volume(upto 2 million). Could you please suggest me which mode of communication to use? Whether BAPI, IDOC or Web Services? Which mechanism will be a good option to transfer large amount of data?

Thanks