Unfortunately it is currently only one provider through CCA :-( I, like others, we asked or required to support multiple trunk; but nothing moves in this direction that probably require a consisting modification of CCA.
Inside CCO, you can find the documentation for CME version 15.x that lists all the new commands, you can load up to six trunks from the CLI but this definitely breaks the rules of CCA and support SBCS.
I do not know in detail what are the limitations of the implementation, but you can start from this link. This waiting for more info from the CCA team .
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