XI 3.0 SR1 Install and Config.

Question

Hello Guru's,
I have read the XI 3.0Sr1 installation guide, the only part i didn't quite catch was about the Adapter Engine installation for Business System. Can anyone be kind enough to explain that to me ? I am quite new to this XI concept..
The scenario is :
Systems : SAP R/3 Enterprise 47x200 Sr1 - WebAS 620
          SAP CRM 4.0 - WebAS 620
          SAP BW 3.5 - WebAS 640.
          External Non-SAP Systems
I will be doing the XI install on a single server, which will have the WebAS 640 ABAP + Java, Adapter Engine and rest of the stuff.
Question is the XI install doc says that the Business Systems should have a WebAS 640 JAVA instance to host the Adapter Engine. Now where does this fit into..do i need a separate server for this, as our R3 and Crm systems are on WebAS 620.
Thanks for your help..
Regards
Nainesh

Answer 1

Hi Nainesh -
The Adapter Engine(AE) installation section(s) refer to an optional decentral/local AE.  The central AE will automatically get installed with the main XI installation (on your single server).  Technically, the central AE will meet the requirements of many/most XI customers. 
>>><i>Question is the XI install doc says that the Business Systems should have a WebAS 640 JAVA instance to host the Adapter Engine. Now where does this fit into..do i need a separate server for this, as our R3 and Crm systems are on WebAS 620.</i>
If you do find the need to install a local AE, yes, this would require a WebAS 640 engine and you'd probably want to do this on it's own WebAS 640 instance (not necessarily on a separate physical server).  However, your R/3 and CRM business systems will probably not need a local AE.  These systems have plenty of ways to communicate with XI and can still use the central AE along with proxies and IDocs.
Some reasons for a decentral/local AE include:
- organizational, security restrictions
- performance, high availability
- protocol requirements (e.g. ftp not allowed and NFS from central AE can't be realized)
Regards,
Jin