Best connectivity (SOAP or HTTP) to Java only PI system

Hi Experts,

We have MII version 15.0 SP03 system and we want to connect to SAP PI (Java only) system for sending xml data.

The HTTP XI action block is failing to connect to PI java HTTP adapter. So for HTTP we are using with generic HTTP post which is connecting successfully.

For Webservice both XI action block and generic SOAP call is connecting successfully.

For receiving data from PI both SOAP and HTTP call is working good.

We wanted to follow a standard Integration pattern, So what will be best connectivity patterns to follow?

Your answers supported with valuable points will be rewarded.

Regards,

Karthik