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• MAINTENANCE ACCESS LINES
• 1 General
  • 1.1 Introduction
  • 1.2 Quiet termination test line
  • 1.3 Test and/or communications access line
  • 1.4 Echo suppressor test line
  • 1.5 Loopback test line
  • 1.6 Echo canceller test line
  • 1.7 ATME No. 2 test lines
  • 1.8 Busy flash signal test line
• 2 Method of access
• 3 Specifications for the test line apparatus
  • 3.1 Tone source characteristics (quiet termination and loopback test lines)
  • 3.2 Transmitted level and timing intervals (quiet termination and loopback test lines)
  • 3.3 Impedance
  • 3.4 Return loss
  • 3.5 Frequency response
  • 3.6 Loopback test line level adjustment
  • 3.7 Digital loopback test
• 4 Signalling system test line test sequence
  • 4.1 Circuit seizure
  • 4.2 Test line answer
  • 4.3 Test line not equipped