Hi Funda,
Appears you are referring to this CCO example of APPN border node and LEN casual connect?
http://www.cisco.com/warp/public/650/76.html
The CCO example would work - but you would NOT require SNASw in the Cisco router attached to Mainframe A. DLSw+ would provide LLC transport across the WAN in the above example.
BUT a much better approach to your requirement of moving to IP and FEP migration is using Extended Border Node (EBN) on MainframeA and MainframeB (if both mainframes are APPN enabled & running CS/390 V2R7 or higher) , and enable Enterprise Extender (EE) on both hosts:
MainframeA (EBN/EE)-----------IP Network--------------MainframeB (EE/EBN)
EBN provides the cross-SNA subnet (different NETID) support, while EE provides HPR/IP IP/UDP transport for SNA traffic between hosts end-to-end - no DLSw+ would be required for SNA L3 transport if EE is deployed! SNASw is NOT required for EE/EBN between mainframes and is not a solution for this purpose (SNASw supports peripheral SNA EN/LEN/PU2.0 devices - see http://www.cisco.com/warp/public/cc/pd/ibsw/snasw/tech/index.shtml for more information). Traffic exiting hosts on both end is already IP encapsulated (and SNA COS to IP precedence marked to leverage Cisco QoS support mechanisms like WFQ/CBWFQ/etc.) - the Cisco network in between is all IP!
