In last one year we faced fluctuation in DWDM DCN Network and different cause and different solution found;

Friends I am now sharing with you case by case in different posts in this forum.

Case-1: 20 out of 40 NE goes offline and after sometimes it comes again online

NE Type: OSN6800

Alarms: NE_NOT_LOGIN alarms in U2000

Analysis: At first NMS design docment analysed. It is found that there are two GEN for this 20 NE; one is primary

another is secondary; and GNE connection mode is revertive;

Findings: Primary GNE is disconnected in regular intervals and secondary becomes active at that time; during this switching time these 20 NEs goes offline. When primary GNE become active again and since connection mode again switch back to primary and during switching it goes offline for short period.

Solution: Ethernet connectivity between AUX board of GNE and router was found loosely connected; Then ethernet cable changed and problem solved.

Good post! One question y friend? in this case you mention that there are three GNEs in the network, so why didn?t configure the third GNE as the third option to avoid the NEs goes offline?

Just as a comment, it?s a best practice to avoid one GNE manage more that 50 NEs because a big amount of NEs controlled only by one GNE can produce a hang up of the SCC boards in GNE.

Thanks for this useful post.

We have to cross-check Ethernet connectivity to avert same scenarios.