Explanation

In a dial-in mode, the destination initiates a session to the router and subscribes to data to be streamed. Dialin mode is supported over gRPC in only 64-bit platforms In a dial-out mode, the router initiates a session to the destinations based on the subscription. All 64-bit IOS XR platforms (except for NCS 6000 series routers) support gRPC and TCP protocols. All 32-bit IOS XR platforms support only TCP.