A Klaytn node can be run with Multi-channel.
If a node is executed with multi-channel configuration, 2 ports are set up for communication. On the otherhand, if a node is executed with single channel configuration, 1 port is set up. If 2 multi-channel nodes are trying to connect, a connection is established using 2 ports. Otherwise, they will use 1 port for communication.
A multi-channel node can be enabled through the flag
--multichannel. If you use
kend, multi-channel is enabled by default due to the statement
kend.conf. To disable multi-channel, please replace the statement with
MULTICHANNEL=0. If you want to run a node with specific ports, flags
subportcan be used. If you want to specify ports values of a connecting peer, check out KNI.
The picture above shows a connection between two multi-channel nodes. Two ports, mainport (A) and subport (B), transfer different messages.
- Mainport(A) is used to transfer messages related to blocks and consensus protocols.
- Block messages include requests and responses of the hash, header, body and receipt of a block.
- Consensus messages include Request, Preprepare, Prepare, Commit and RoundChange. The meaning of the messages can be found in PBFT.
- Subport(B) is for transferring transaction messages.
Single Channel Server
The picture shows a connection between two single channel nodes or between a single channel node and a multi-channel node. In this case, all messages related to blocks, transactions, and consensus protocols are transported via the same port.
- Single Channel : A single channel node uses one port (default is 32323).
- Multi-Channel: A multi-channel node uses two ports. The ports can be specified in
subport. In Klaytn, the default values of
subportare 32323 and 32324, respectively.
- You might not set
subportwhen connecting to multi-channel node. In this case, at first, a Klaytn node tries to connect using a single-channel. In handshake process, the actual peer's port numbers are revealed. If the peer is a multi-channel node, the ongoing connection will be canceled and a reconnection will be made with the updated ports.