Assumption: Outlined Deployment options are for Gateway 2.0 SP06 with SharePoint 2010 and SharePoint 2013 only (with everything On-Premise).
Integrating SharePoint 2010 with SAP Business Suite
Here, in this case, Duet Enterprise 1.0 FP1 must be used with Gateway 2.0 SP06
Gateway Deployment Approach: Here, all 3 Types of Gateway Deployment Approaches can be used i.e.
a) Central Hub (IW_FND, GW_CORE) with IW_BEP (Backend Event Publisher) in the Backend
b) Central Hub (IW_FND, GW_CORE) along with IW_BEP in Gateway System itself.
c) Embedded Installation (IW_FND, GW_CORE, IW_BEP in Business Suite Server itself)
However, careful selection must be made while choosing one of these options depending on version of your backend business suite system and underlying NetWeaver layer.
If you choose to go for option b and c, you must install component for Backend Event Publisher (IW_BEP) in Business Suite System (For Ex. ERP, CRM etc.). Minimum requirement for installing this Add-On in the SAP Business Suite backend system is SAP NetWeaver 7.00 Support Package 18.
Details of Minimum requirements for each Gateway component with Pro and Cons of each deployment types can be found here: http://help.sap.com/saphelp_gateway20sp06/helpdata/en/88/889a8cbf6046378e274d6d9cd04e4d/frameset.htm
If you decide to use Embedded Installation, extra care must be taken while doing the Duet Enterprise Configuration such as Self Pointed RFC Destinations (while doing connection settings between Gateway and Backend) , configuring system to accept Assertion/Logon Tickets (really needed?) etc.
SSO and Security Approach: In Duet Enterprise 1.0, calls from SharePoint 2010 to Gateway 2.0 are provisioned through SOAP/HTTP. HTTP messages are encrypted via SSL. Technology used for Single-Sign-On in this case is SAML 2.0 (Recommended by SAP for SSO with Cross Site Applications i.e. Applications existing in different domains).
Web Service Development Approach: Exchange of information between SharePoint and Gateway happens through SOAP Calls via HTTP because SharePoint 2010 does not support consuming OData services out-of-the-box. But ideally this should not deter us from using OData Channel. OData services are light weight and are suitable channel for all types of devices.
Hence, with Duet Enterprise 1.0’s Feature Pack 1, an extension for the development tool “BDC Browser” is provided .This provision is called “SOAP Bridge” (Logical Name). It facilitates conversion of OData Output to SOAP Output. This means that you can do OData development with latest version and deployment of Gateway (using SEGW). Then, at the end, when you want to expose it to SharePoint 2010, you can use the SOAP Bridge in between to convert the OData output to SOAP output (Flattened Service Output).
The main advantage of using this approach is minimum disruption when you upgrade to SharePoint 2013. SharePoint 2013 supports OData Service Consumption out-of-the-box. When you upgrade, you just have to get rid of the SOAP Bridge and thus, no change would be required in already done developments. However, Generic channel is also supported for developments already done. But, this channel is not recommended for planning new developments.
Integrating SharePoint 2013 with SAP Business Suite
Here, in this case, Duet Enterprise 2.0 must be used with Gateway 2.0 SP06
Gateway Deployment Approach: Here, in this case as well, all 3 Gateway Deployment Approaches can be used. All the details are same as I mentioned above.
SSO and Security Approach: As of now, OData doesn’t support SAML 2.0 which is ideal for cross domain SSO. Best fall back option in this case is using X.509 client certificates. Thus, in Duet Enterprise 2.0, SSO is engineered via X.509 certificates issued by its SharePoint Add-on. Here again IDP lies on SharePoint. As in SharePoint 2010, Messages (HTTP), here as well, are secured using SSL.
Web Service Development Approach: Here, as I mentioned above, we must prefer OData Service Development via Gateway Service Builder (SEGW) because SharePoint 2013 support OData consumption out- of-the-box. However, again, Generic channel is supported for developments already done but not recommended for new developments.
What Changes with NetWeaver 7.40?
Below is the noteworthy extract from: http://help.sap.com/saphelp_gateway20sp06/helpdata/en/88/889a8cbf6046378e274d6d9cd04e4d/frameset.htm
“As of SAP NetWeaver 7.40, the core software component for SAP NetWeaver Gateway is SAP_GWFND, which contains the composite functional scope of IW_FND 250, GW_CORE 200, IW_BEP 200, and IW_HDB 100.
Consequently, if you have an SAP NetWeaver 7.40 installation, you can use SAP NetWeaver Gateway without having to install any additional software components.
If you have an SAP NetWeaver 7.40 installation and you have previously created services for the Generic Channel that are still in use, you must install the software component IW_FNDGC 100. You only need to install this optional component if you have existing Generic Channel services.”
To me, this all sound like a clear message that, in Future SAP landscapes, NetWeaver Gateway will become THE technology for exposing SAP data to all types of devices and platforms and Duet Enterprise should definitely benefit from it.