This article will explain the difference between UDP and TCP, when selecting the protocol to use for the Talk2m VPN tunnel.
Flexy 20x Series
Which Protocol Should I should I use for my VPN?
When using the Ewon product line, you will have the ability to set a VPN tunnel for remote access. Our Talk2m VPN tunnel utilizes one of two different protocols to establish the tunnel. One is UDP (Port 1194), and the other, is TCP (Port 443). Choosing the best protocol often depends on the network and environment.
Picking the correct Protocol
UDP is a Datagram-oriented protocol. The protocol does not utilize any handshaking, and is a connectionless protocol. It is faster, simpler, and more efficient than TCP. UDP is lightweight, and has no overhead on the network. There is no sequencing of data, and an 8 byte fixed length. The data is not retransmitted in case of lost packets, and uses only the basic of error checking using checksums. A stable and consistent Internet connection, and noise-isolated environment is best suited for UDP
TCP is a Connection-oriented protocol. The protocol utilizes handshaking such as SYN, ACK, and SYN-ACK for communication. TCP is a slower, but more reliable than UDP. TCP is heavy-weight, and has low overhead on the network. There is a sequencing of data when transmitting, and has a 20-60 byte variable length header. Retransmission is possible in case of lost packets, and utilizes extensive error-checking mechanisms. It provides flow control and acknowledgement of data. TCP is best utilized for high noise interference networks, and with less than stable Internet Connection.
UDP is often the best choice when the unit uses Ethernet as the Internet connection. The consistent connection, and rate allows the Tunnel to broadcast the data without the fear of lost packets. However, if the network environment has potential noise interference, TCP is suggested. TCP will protect against packet loss from noise on the ethernet line.
There is more to consider when choosing Protocols on a WIFI network. An isolated network that is free from interference from the environment (other WIFI networks, impedance from the location, connection congestion) is suited for UDP. TCP is advised when there are several WIFI networks in the vicinity, high amounts of impeding materials (copper, steel, drywall), and/or high congestion. TCP will establish a connection with the destination, and utilize handshakes to reliable transfer data.
Like WIFI, cellular connections require more consideration when choosing environments. TCP is often suggested as cellular network strength is not able to controlled by the onsite network. There considerably more congestion, and high probability of network interference from the environment. Error checking and retransmission of lost packets, provide a safeguard for a stable VPN connection. UDP can be used, but it will not provide the reliability of connection.
KB-0209-00 - Addresses and ports used by Talk2M