The invention may be used in many different types of applications including {HEAD ~ communication interface devices} that convert DS3 to STS 1, and {TAIL ~ STS} 1 to DS3 
The invention may be used in many different types of applications including { HEAD ~ communication interface devices } that convert DS3 to STS 1 , and { TAIL ~ STS } 1 to DS3
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH