A. ordinary clock
C.transparent transmission clock
D.transparent transmission clock
E1 service clock in STM-1 board of 9000 32R1 version works in()clock mode by default. But it needs to be configured into()clock mode to ensure clock sync when the existing network runs MSC main boards and clock sync is not configured for the whole network.
C.nE2E transparent transmission clock
D.nP2P transparent transmission clock
B. clock event and clock="1"
D. clock event and clocke'
B.nservice recovery timing (customer)
A.The line clock tracing should follow the minimum path requirement.
B.The clock compensation should be given if there are many nodes on the link and each of them extracts the clock from a distance to the near.
C.It is suggested that SSM protocol is used in the whole network (user-defined mode II) to provide clock protection and avoid clock looping.
D.For the clock synchronization scheme of CES service, the PE synchronization mode is the first choice and the adaptive mode is the second choice.
B.support GPS interface function; provide 1PPS+TOD signal
C.support sync Ethernet interface function; support sync Ethernet clock source
D.support network clock sync via E1 interface; provide clock signal as required by ITU-T G.813