Connecting SAP CRM (SAP ECC) 
Procedure
Logon to the SAP ECC system.
To define an RFC destination in the SAP ERP system, access the activity using one of the following navigation options:
Call transaction code SM59.
In the SAP ERP IMG menu, choose
SAP
NetWeaver 
Application Server
IDocInterface/Application Link Enabling (ALE)
Communication Create RFC Connections
.
On the Display and maintain RFC destinations screen, choose Create and enter the data according to the RFC destination:
Field name
User action and default values
RFC Destination
Erp_<ERPSID><ERPCLIENT>_to_Crm_<CRMSID><CRMCLIENT>
(for example: Erp_ER1001_to_Crm_CR1005)
Connection type
3
(Connection to ABAP system)
Description
SAP CRM system
Choose ENTER.
Technical Settings
Load Balancing
No
Target host
<SAP CRM target host name>
(for example: pwdf0421)
System number
<SAP CRM target system name>
(for example: 74)
Save as
IP Address
Logon/Security
Security Options
Trusted system
No
Logon Screen
deselect
SNC
Inactive
Logon
Language
EN
Client
<SAP CRM target client>
(for example: 001)
User
ERP2CRM
Password
<your password>
(password you have chosen in user maintenance)
Current User
deselect
Unencrypted Password (2.0)
deselect
Choose ENTER.
MDMP & Unicode
Communication Type with target system
Set Unicode flag if the Unicode test has been executed successfully.
This test can be performed by choosing Unicode Test in the menu area. The RFC destination has to be saved before the test can be performed. An information message appears (Example of a message: Target is a Unicode system (character size 2)).
Choose ENTER.
In the Special Options tab page, deselect Trace and Slow RFC Connection.
Choose ENTER.
Save your RFC destination.
To test your newly created RFC connection, choose Connection Test.