[Info-vax] Rethinking DECNET ?

[JF Mezei]

On 14-09-02 11:14, Bill Gunshannon wrote:

> TCP/IP has never "pretended" to be anything OSI.  Some people have
> tried to shoehorn it into the 7-layer Model


The 7 layer model is not really specific to "OSI". It is a generic
breakdown of networking functionality which was used in building the OSI
networking stack, allowing each vendor to test compatibility of each layer.

The OSI networking stack included applications such as file transfer. So
it rises to the top.

The IP stack stops at the TCP layer, so it doesn't include applications
such as FTP, SMTP, TELNET  etc.  So the IP stack stops at transport or
session for TCP when viewed in certain ways.

Because there are many subprotocols above IP (TCP, UDP, GRE, ICMP etc),
the whole IP stack is more like a tree with many branches at the upper
levels, some rising higher than others.