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Dial 1-800 plug Holes: Page 9 of 11

  • We configured one ETM Communication Appliance (Model 3200) to support 16 North American ISDN-PRI spans, and a second ETM appliance (Model 1010) to support four analog circuit ports. The appliances run customized versions of Linux.

    Counting on Abacus

    We would not have been able to thoroughly test the ETM without the generous loan from Spirent of an Abacus Test System. After sorting out our initial configuration and settings (somewhat challenging as we were setting up a closed-loop test environment), we hammered the ETM with hundreds of thousands of simulated calls from the Abacus in the course of a month.

    We configured two ISDN PRI cards (mapping 23 "extensions" each) in the Abacus, one to receive "incoming" calls and one to generate our "outbound" calls, yielding 10-digit source and destination numbers for testing. We used a staggered test-dialing cycle (Extension 1 direct-dials Extension 24, makes connection, keeps line open as a voice call for 35 seconds, then disconnects. Keep going through Extension 23 dialing Extension 46, repeat ad infinitum).

    Note that we did not connect the Abacus to our production PBX; this was a standalone test environment that placed the ETM equipment in-line between the two Abacus cards.