mishka75
2011-12-21, 06:39 PM
Greetings to all!
Useful document Pocket Guide for E1 and PDH Testing provides information on:
1.PDH and T-carrier hierarchies
2.The E1 frame is the first hierarchy level.
3.The A multiplexer calculates and writes the CRC code, and the multiplexer B reads and
checks the code.
4.The PDH hierarchy
5.The higher PDH hierarchies. A bit-oriented justification process is used to fit tributaries
created with clock impairments.
6.PDH hierarchies are not synchronous, and variations can be expected in the bit rate clock -
in this case a justification mechanism is implemented.
7.When a multiplexer detects an LOS or LOF, it sends an RAI to its partner multiplexer
and forwards an AIS to the next NE.
If the material was useful for you please add reputation.
Useful document Pocket Guide for E1 and PDH Testing provides information on:
1.PDH and T-carrier hierarchies
2.The E1 frame is the first hierarchy level.
3.The A multiplexer calculates and writes the CRC code, and the multiplexer B reads and
checks the code.
4.The PDH hierarchy
5.The higher PDH hierarchies. A bit-oriented justification process is used to fit tributaries
created with clock impairments.
6.PDH hierarchies are not synchronous, and variations can be expected in the bit rate clock -
in this case a justification mechanism is implemented.
7.When a multiplexer detects an LOS or LOF, it sends an RAI to its partner multiplexer
and forwards an AIS to the next NE.
If the material was useful for you please add reputation.