Not exactly Erik because the MCP2150 is an irda controller supporting DTE applications and the MCP2155is an irda controller suppoting DCE applications. But both are secondary devices.
In the data sheet of the MCP2150 say:
"When two devices that contains the irda standard feature are connected, there is geerally one device that has something to do and the other device that has the resorse to do it".
The primary device must to determine if the secondary device can do the work. Once the ir-link is done the data can flow in any direction but the primary device must begin communication to establish cetain parameters like link initialization and data rate.

Thanks

Roberto Muñoz