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A7 Proving period T4

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A7 Proving period T4


I'm in the process of running MTP2 tests between two A7 signaling terminals (SSP as the DUT and an SS7 tester). the links are transported over SCTP with delay of around 300ms RTT between the terminals.

When I initiate an emergency alignment on the DUT by sending SIE, the tester will receive it after 150ms, send SIE back and start T4e measurement. the SSP will receive the SIE response after 150ms and start the proving period and T4e.
At this stage we already have the tester T4e measurement longer in 150ms than the DUT.
At the end of T4e, DUT will send FISU which again will be received by the tester in 150ms delay. so now the tester T4e measurement is 300ms longer than DUT.
T4e is 600ms and the ANSI spec allows 10% deviation = 660ms. but with 600ms + network delay of 300ms the test can never pass.

Is there something wrong with the test? is it possible to establish A7 link with more than 60ms delay?

Edited by: admin on 05/16/2010 - 04:32