> Wired (no, I don't usually read it) reports that hackers were intending to
> disable Iraqui computer networks, which were supposedly accessible by
> dialup, and using a 'vintage' protocol called X.25. Could someone tell me
> what sort of protocol this is and what machines it's likely to involve?
X.25 is an ITU (CCITT) standard for packet switching networks.
Basicly like IP (or better TCP/IP, since it is connection orientated),
and in fact, before the IP boom of the last 5 years X.25 networks
have been the mayor carriers. They are still common, and the infra-
structure ist still available around the world. There are PADs
(Packed Assembly/Dissasembly) units to offer async (and sometimes
sync) connetions for 'dump' (non X.25) units, or you have to use a
interface, capable of X.25. X.25 connections are leases lines in
most cases, while connections via a PAD was leasd line or dial up
connections. To build up a connection a NUA (Network User Address)
is used, which is structured like a international telephone number
(maximum 15 digits). When using a dial up line, a terminal had to
be identified by a NUI (Network User ID) and a password. Connection
speed run from 300 to 2400 Bd for dial ups and 1200 to 64 for leased
line (at least here in Germany) - more than 64K waspossible, but
not afordable :) For performance, security and scalability, X.25
outperforms TCP/IP clearly as an wide area network. on a simple
view, X.25 could be compared to ATM networks (althrough the QOS
was less controlable).
Beside this (worldwide) public X.25 Networks, that behavied like
the telephone system (from a users view), private X.25 Networks
are very common in use at telcos and power (network) companies for
internal/controll purposes. There are still new installations.
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
Received on Tue Jan 12 1999 - 12:34:47 GMT