e1-prbs-test - Utility to test for bit errors on E1 lines
=========================================================

e1-prbs-test can be used to test for bit errors in E1 transmission
lines. It consists of a sender and a receiver, which should be used
on either end of the E1 line.

Transmitter and receiver can be on the same machine, or on different
machines.

The code currently works directly on DAHDI or via osmo-e1d, so both
DAHDI-supported E1 interfaces as well as osmo-e1d supported ones
are supported at this point.

The test works by sending timeslot-specific PRBS sequences of 512 bit
(64byte) length on the transmit side, and by correlating to those PRBS
sequences on the receiver side.

The use is relatively simple:

For the A-side, assuming you would want to use DAHDI span 1:
  e1-prbs-test /dev/dahdi/chan/001

For the B-side, assuming you would want to use DAHDI span 2:
  e1-prbs-test /dev/dahdi/chan/002

The test will run indefinitely.

For using osmo-e1d, use "e1d:0:0" and "e1d:0:1" for interface 0 line 0 + 1
instead of the /dev/dahdi/chan/xxx notation.

If you'd like to get an interim report, send a SIGHUP to
e1-prbs-test.

If you'd like to stop, simply press Ctrl+C.
There is a two-stage shut-down process.  When you press Ctrl+C for
the first time, the report is printed, but transmission continues. At
the second Ctrl+C, the process terminates.   You must press Ctrl+C for
the first time on both A and B side, before pressing it the second time
on the A-side in order to get correct results.