When acting as a client to Morgan Stanley FX, the IAF should be configured with the Morgan Stanley FX specific configuration file, the distribution version of which can be found here:

Note that the requirement for a MSFX-specific configuration file means that an IAF using this configuration file must be used for MSFX FIX sessions only. The FIX adapter will not interoperate correctly with other FIX servers once it has been configured for MSFX operation. If you need to connect to other FIX servers as well as MSFX, the non-MSFX sessions should be configured in a separate IAF instance. However, MSFX and non-MSFX session can co-exist safely within the same correlator instance.