User manual

Wide Bank 28 DS3 - Release 2.4 July 2004 7-35
Diagnostics & Troubleshooting
Testing DS3 Interfaces
Testing the DS3 Near-End with Loopback Tests
 DS3 Equipment Loopback ... 7-35
 DS3 Line Loopback with M23 Framing ... 7-35
 DS3 Line Loopback with C-bit Framing ... 7-36
 DS3 Payload Loopback with M23 Framing ... 7-36
 DS3 Payload Loopback with C-bit Framing ... 7-36
DS3 Equipment Loopback
1. Configure the DS3 for equipment loopback.
(A:Active)> ds3 equipment on
2. Apply PRBS from the test set on the low-speed circuit, and verify that the test set synchronizes
on the pattern without errors.
3. When complete, disable equipment loopback.
(A:Active)> ds3 equipment off
DS3 Line Loopback with M23 Framing
1. With a test set on the DS3, configure for M23 framing and apply a line loopback.
(A:Active)> ds3 framing M23
(A:Active)> ds3 clock line
(A:Active)> ds3 line on
2. At the test set apply a PRBS pattern, and verify that the test set synchronizes on the pattern
without errors.
3. When complete, disable line loopback.
(A:Active)> ds3 line off