Separating application services from concurrent processing

We are setting up EBS R12.2 environment with 7 Node RAC and 6 application nodes (1st 3 are application services nodes and remaining 3 are concurrent processing nodes). There is one to one relationship btw 1st 6 RAC nodes and 6 application nodes to avoid excessive block shipping over interconnect. 7th RAC node is for adhoc and 3rd party s/w connections.

As we are going to run application services and concurrent processing on separate servers
1. What do we specify for s_tools_twotask on concurrent processing servers?
2. What do we specify for s_cp_twotask on application services servers?

[ErmanArslansOracleBlog]

You got to check the tnsnames.ora files on your apps nodes and set those *_twotask context variables to the tns entry names of the relevant ones according to your needs.. If those tns entries (the standard ones I mean) are not helping you for your specific case, then you got to add some manual entries to those tnsnames.ora file and use those custom tns entries in your apps node context files.. Of course, if you need to do that, you should create a SR to Oracle Support and get their approval.. + you got to manage those customization of yours.. (they may be overwritten after patching, after running autoconfig etc..)