Mastaka / Bill,
>> Michel Py wrote:
>> In terms of design, if you do TCP/IP *only* design, the TCP/IP model
is
>> probably enough. However, the Internet is not only TCP/IP. Carriers,
for
>> example, don't care much if their fiber transports TCP/IP or IPX or
>> voice or video or GigE.
> Masataka Ohta wrote:
> No.
> Anything at or above transport layer is a layer internal to
> end systems and has nothing to do with networking or network
> protocols. Seperation of transport and application layers is
> a overkill for a best effort network, though it may help
> standardize the internal design of end systems such that
> anything supported by kernel belong the transport layer. You
> can check the reality that application and transport areas
> of IETF are now almost identical, though, historically,
> trasnsport area was working on protocols likely to be
> implemented in kernel. In addition, defining a thin transport
> layer may be useful over a hypothetical port-number-aware
> network such as that supporting RSVP. However, forcibly
> defining a session-layer-aware network is a layer violation.
I don't disagree for the upper part of the model, but all the examples I
have used in this thread were about the lower part of the model.
>> Michel Py wrote:
>> And, there are complex multi-protocol networks that a) don't
>> use only TCP/IP and b) would not be able to use the TCP/IP
>> model anyway because it's too simple.
> Bill Cunnigham wrote:
> * Would not be able to use TCP/IP.*
> How can that be changed?
If I had to design a model it would be:
Michel's TCP/IP OSI
model model model
+--------------+ +---------------+ +---+--------------+
! ! ! ! ! 7 ! Application !
! ! ! ! +---+--------------+
! Application ! ! Application ! ! 6 ! Presentation !
! ! ! ! +---+--------------+
! ! ! ! ! 5 ! Session !
+--------------+ +---------------+ +---+--------------+
! Transport ! ! Transport ! ! 4 ! Transport !
+--------------+ +---------------+ +---+--------------+
! Network ! ! Internet ! ! 3 ! Network !
+--------------+ +---------------+ +---+------+-------+
! Logical Link ! ! ! ! ! Data ! LLC !
+--------------+ ! Network ! ! 2 ! Link +-------+
! Media Access ! ! Interface ! ! ! ! MAC !
+--------------+ ! ! +---+------+-------+
! Physical ! ! ! ! 1 ! Physical !
+--------------+ +---------------+ +---+--------------+
I understand that people that have used the TCP/IP model don't care much
of what's inside the Network Interface layer, but there is a bunch of
stuff there that could use layering. That's why, short of having my very
own model drawn above, I keep using the OSI one for
explanatory/educational purposes.
Michel.
