sonusStChannelBindingChannel 1.3.6.1.4.1.2879.2.1.3.1.7.1.3

T1/E1 span or OC12 port number to provide the recovered clock source. T1 span range is 1-12(CNS10), 1-28(CNS30), E1 span range is 1-8(CNS20), OC12 port number(PNS20) is 1 only.