Side chains (see linked question ) can be seen as a blockchain attached to a "parent" blockchain using a "two way" peg. Smart contract addresses are generated deterministically(HD wallet style), but the wallet style addressing is for smart contracts.
Unlike smart contract addressing, when the Parent blockchain addresses the side chain(or vice versa) are there addressing issues like making deterministic wallet style addresses for the chains(a main chain could make a wallet style address for a sidechain), or communicating between the two blockchains(Parent and Sidechain), or is done using network addressing via sockets(and so on..)?