E1 MFR2 abcd signaling bits

Condition/Direction Forward
abcd		Backward
abcd
Idle
1001
1001
Seize ->
0001
1001
Seize Acknowledge <-
0001
1101
E1 MFR2 dial    
Answer <-
0001
0101
Clear Back <-
0001
1101
Clear Forward ->
1001
0101
Release <-
1001
1001