"TCP packet" is a pretty common colloquial term which is also factually wrong. There is no such thing as "packet" at the TCP protocol layer.
This paper is discussing the tunnelling of payloads with PPP over SSH.
You can see in the stacked diagram that "TCP" appears in two layers of the protocol stack, as does IP.
Essentially, they're encapsulating TCP segments inside other TCP segments, although there are also trappings of IP, PPP, and SSH protocols in-between those.
This isn't a VPN use case at all. And if a VPN is forwarding IP packets, then it's forwarding IP packets.
"TCP packet" is a pretty common colloquial term which is also factually wrong. There is no such thing as "packet" at the TCP protocol layer.
This paper is discussing the tunnelling of payloads with PPP over SSH.
You can see in the stacked diagram that "TCP" appears in two layers of the protocol stack, as does IP.
Essentially, they're encapsulating TCP segments inside other TCP segments, although there are also trappings of IP, PPP, and SSH protocols in-between those.
This isn't a VPN use case at all. And if a VPN is forwarding IP packets, then it's forwarding IP packets.