Framing
Framing format in use for the T1 or E1 line:
|
ESF |
Extended superframe---default for T1. |
|
D4 |
D4 framing, alternative format for T1. |
|
CRC4 |
Cyclic redundancy check 4---E1 default. |
|
FAS |
Frame Alignment Signal---alternative format for E1. |
|
NONE |
|