There is a well-known rule that cannot be broken: The speed of light is 299,792,458 meters per second. It is also a universal constant that does not change, and the maximum speed at which data travels through the Internet. At least, for now.

This is quite fast. Nevertheless, it is also an essential handicap because of its limits in using the Internet to exchange information and data over a WAN. Picture it this way: when a petition is sent out, the time a packet needs to travel from point “A” to point “B” and back to point “A” is called the latency of the network which is also known as the round-trip time or network response time.

We know that the speed of light is constant, and we also know that latency is directly proportional to the distance between point “A” and point “B”. In simple language, this means that the longer the distance between the two points, the longer the delay.

Human knowledge says that increasing bandwidth will lead to improved performance. But we should also remember that TCP/IP (transmission control protocol built on the Internet protocol) limits the number of concurrent bytes transmitted, regardless of the size of the transmission pipe. TCP/IP restricts the amount of data on a connection to avoid congestion tailbacks in the network. It is also a stream-oriented protocol, which means it is designed to provide the application layer software with a service to transfer large amount of data in a reliable way. Once the first packet is out, it will wait for the acknowledgement or ACK, and upon confirmation, it establishes a full duplex virtual circuit between the two hosts so that both can simultaneously transmit large amounts of data without specifying the destination. Hence, the higher the latency, the longer the TCP/IP will have to wait to transmit its packets.

When it comes to CIFS (common Internet file system), SMB (server message block), or NFS (network file system), it is a whole new “slow” show. These are extremely loquacious protocols. They were also designed for LAN use and are not very efficient for WAN transmissions. When you employ them across long distances, the round-trip time increase from a few milliseconds on the LAN to hundreds of milliseconds on WAN which results in dramatic decrease of the speed of file transfer because the sender must wait for the receiver to acknowledge a small block of data before proceeding with the next one, and so on. A simple action such as retrieving a file attribute can require numerous round trips across the network and thus slowing down operations.

The point of this post is to help you understand that setting up a VPN (SSL or IPsec) with the hope of moving files from one point to the another by “dragging and dropping” or executing an app that requires multiple RPCs (remote procedure calls) is not going to work out well no matter how wide your communications bandwidth is.

It is more efficient to use an FTP or TCP cloud-based storage space for files or an RDP session for your applications.

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Wajdi A. Ayach

Author Wajdi A. Ayach

Changes are challenging, and cybersecurity is like a moving target that we have to mitigate through continuous adjustments.

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