[VoIP] Itec Switch

[John Novack]

ITEC was a company in Huntsville? AL that built electronic control SXS 
switches for use either to add to existing SXS or one could have a 
complete ITEC switch as a central office.
Here we mostly refer to the EMS-1. The EMS-2 was later, microprocessor 
controlled and is reported to be even more of a juice hog than the 1A ESS.
ITEC EMS-1 has several parts.
A shelf of circuit boards, 8 circuits to a card, that are the line 
circuits. a full shelf would be 96 line circuits, strappable for loop or 
ground start. Each card contains the necessary support circuitry.
A shelf of line finders, up to 10, with allotter circuitry, and a shelf 
of relay matrix cards round out a linegroup. The linefinders can 
optionally be equipped with DTMF to pulse converter cards that appear to 
be Teltone cards used on many SXS systems.
The selector shelf, equipped with digit absorbing circuit cards, up to 
10, and another shelf of relay matrix cards. Digit absorption can be 
strapped for fairly complex schemes if required.
Connector shelf, up to 10, an optional test connector card and optional 
pbx hunting card, with a shelf of relay matrix cards round out the EMS-1 
system.  Connectors had several options for frequency ringing and code 
ringing party lines, and reverting call by directory number.
AFAIK ITEC never made any tone or interrupter circuits. They did have a 
large selection of trunks, Loop and E&M,  and filter fuse panels.
A complete 96 line switch can easily fit into a 7 foot 23 inch rack, 
with space to spare for power and tone.
Most of the inter shelf connections are made with plug ended 25 pair 
cables, commonly used with 1A2 key systems. Pin out follows a scheme 
seen in some later WE equipment that has pair one as T&R, pair two is 
Sleeve for circuit one and circuit two, pair three is T&R for circuit 
two. This keeps noise and crosstalk to a minimum, and allows one to use 
66 style blocks for a distribution frame. Mine has the lines on one side 
of a split 66 block, connector outputs on the other side, and bridging 
clips joining the two, which keeps cross connects to a minimum at least 
for single party lines. Power and tone were individual wire wrap. Though 
the EMS-1 doesn't make a lot of the nice EM sounds of the older SXS, 
each section can be used with EM switches if desired. Circuit cards have 
lots of jumpers to adapt any part of the system to the various SXS 
schemes in use at the time.
I am finishing up a CD of all the ITEC documents I have been able to 
find, which I will make available to anyone that needs or wants the 
information.
Also Rickey Jennings, Phil McCarter and Bob Dickerson all still have 
some pieces available for sale that would allow interested parties to 
make their own switch or add to an existing one. Costs are minimal, and 
up to the individuals selling what they have.  Not a large amount left 
around though, so I would not wait too much longer if you want to get 
into ITEC. 
Probably much more than you wanted to know about ITEC.

As to Asterisk and CNET - you will probably discover that most of the 
prepackaged Asterisks can be more difficult to configure than a plain 
vanilla system
I have had good success with AstLinux though, and have configured a few 
for CNET users on HP thin clients for a minimal system that is easy to 
get up and running
Documentation on AstLinux isn't great, but it will run in either a 64 or 
128Meg Flash memory, and a "keydisk" flash memory plugged into a USB port.
It can also be installed on a hard drive.

Best of luck with all your efforts.

John Novack
CNET 666-9900


Frank Hansche wrote:
> Can anyone give me any information on the Itec switches?  What do they cost and are they available?
>
> After a long battle (against my lack of knowledge), I have my Asterisk
> system running.  For now, I am having to run Trixbox, but I have just
> rebuilt a computer to run straight Asterisk.  I'll be turning that into my
> tandem.
>
> Also, a big thank you to everyone who responded to my last set of
> questions.  I learned a lot, but have a long way to go.
>
>   

-- 
Dog is my co-pilot