Infomation on the TXEx exchange based processors.

typed by iNFERNO

The TXE series of switches are widely used in English phone system. They
are a step down from the digital switches (TXD, AXE10, UXD5 etc..), being
electronic (and not fully digital). A TXE is controlled by its exchange
based processor which is an ICL DRS300 level 70 microcomputer running UNIX.
What you must remember is that it doesn`t handle the calls for the resident
area, the switch itself does that but it does control the switch and is the
main interface between man and computer.

The E.B.P is connected to both the PSTN (Public Switched Telephone Network,
the one you use) and the PSN (Packet Switched Network). General
communication between the EBC and external computers is made using the
PSN, but when this is unavailable the PSTN is used. For this reason, if
you do some scanning of TXE exchanges you will probarbly come across it
after some time (but thats a LOT of time scanning!!). Inside the actual
exchange it`s connected to a micro-LAN (Local Area Network) from which the
terminals in the exchange can access it - if the user has full account
details.

All the EBPs in an area are connected to a Central Site Processor which
handles up to thirty other EBPs, which communicate as `nodes` on an
X.25 network (the PSN as mentioned before).

Being a typical UNIX system, when logging on the `Login` prompt will
show and the user will have to identify himself (or herself??). Again,
some users may be presented with the UNIX shell prompt instead.

It users a COMFORTE menu system (COMputers FOR Telephone Exchanges) which
displays all the options on screen (i`m not too sure how this is handled
remotely, but it is simular i think).

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