How to transfer a token from one chain to another?

As we known , Cosmos is an internet of blockchain. I am wondering how can I transfer token from one chain to another?

Let’s say we have two chains which are instances of cosmos-sdk: BlockchainA and BlockchainB.
BlockchainA runs on server 172.10.0.100 and BlockchainB runs on server 172.10.0.101
A is an address on blockchainA and B is an address blockchainB.

Tasks to test are:
1, Send 5tokenA from A to B
2. B exchange 10tokenB for 5tokenA.

Does anyone know how to do this test? Please drop your commands here.
Thanks in advance.

Hi Ping,

the IBC testnet is a post launch milestone.

OK, I will keep eyes on it.