{TAIL ~ Each STS3 C link} carries {HEAD ~ 640 DS0 channels} per 125 microsecond frame 
{ TAIL ~ Each STS3 C link } carries { HEAD ~ 640 DS0 channels } per 125 microsecond frame
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH