When you architect and implement a VPN deployment as a part of standalone setup or leveraging VPN technologies as one of your building blocks of your SD-WAN product architecture, one thing you have to always bear in mind is the amount of overall VPN Tunnel Network Overheads. Fundamentally these overheads are caused due to VPN traffic packet encapsulations. And the complexity of this and the count of multiple extra packet headers dictates the overall overhead. And sometimes along with various network layer packet headers you may also tend to include any extra meta-data, which can be specific to that VPN stack and/or any custom proprietary meta-data.
So these overheads in turn affect your VPN traffic MTU and packet processing latency caused due to adding these extra network headers as well as VPN payload encryption. So here is my detailed multi-episode YouTube video series where I discuss about VPN Tunnel Network Overheads.
Refer:
Building an encrypted travel wifi router ↗
VPN Stack Architecture | Virtual Network Interfaces | OpenVPN | Wireguard | VTun | IPsec ↗
I also conduct sessions/classes on Systems and Network Software Programming, Linux Kernel Programming and Architecture. If you are interested, click HERE for more details.
If you have any queries or anything to discuss further on Linux Kernel Programming and writing Kernel modules kindly feel free to contact me.