Very Computer

by **pbtpc..** » Thu, 06 Feb 1997 04:00:00

hello,

Could someone explain to me the physical aspect of ports. I am
having trouble unterstanding if a port is like a box of some sort, or if
a port is more of a term used to describe the different ways of logging
on to a machine.

pat

by **Manuel Mora** » Fri, 07 Feb 1997 04:00:00

>hello,
> Could someone explain to me the physical aspect of ports. I am
>having trouble unterstanding if a port is like a box of some sort, or if
>a port is more of a term used to describe the different ways of logging
>on to a machine.
> pat

Ports identify SERVICES within one HOST.
Sometimes a PORT for one service (synchronous), sometimes a port for
each client of a service and a MASTER port for accessing the service
(assynchronous).
__________________________________________

by **Stephan LEBU** » Fri, 07 Feb 1997 04:00:00

Manuel Morais wrote in article

Quote:> Ports identify SERVICES within one HOST.
> Sometimes a PORT for one service (synchronous), sometimes a port for
> each client of a service and a MASTER port for accessing the service
> (assynchronous).

The IP layer of the architecture contains the address information
which specifies the destination host to which the datagram is being
sent. In fact, datagrams are not intended just for particular hosts,
but for particular agents within a host, processes or other entities
that are the actual source and sink of the data. IP performs only a
very simple dispatching once the datagram has arrived at the target
host, it dispatches it to a particular protocol. It is the
responsibility of that protocol handler, for example TCP, to finish
dispatching the datagram to the particular connection for which it is
destined. This next layer of dispatching is done using "port
identifiers", which are a part of the header of the higher level
protocol, and not the IP layer.

part of RFC814

In fact, a port and a protocol identifie uniquely a service.

--
------------------------------------------------------------------------------
Stephan LEBUF - DUNE Concept Ingenieur systemes et reseaux
7/9, rue Paul Vaillant Couturier Consultant en securite informatique

------------------------------------------------------------------------------

Very Computer

PORTS

PORTS

PORTS

PORTS