Our Network is :
UA5000 - to - Metro1000V3 - to - Metro3000 - to - MD5500
All METRO1000 are connected with Metro3000 in ring topology.
Our access network customer complaint to Huawei helpdesk that Frame fault, board fault & EMU fault alarms are observed at ONU 18 to 28. while no power issue exist at any ONU. On taking feedback from transmission NMS, we found out that all Metro1000V3 equipment are online.
TU_AIS alarm at all SP2D and PQ1 cards E1 interface pins.
BIP_EXEC alarm at SP2D pins.
- At first we observed the alarms at MD5500 end and found no clue.
- Check all loopbacks and found everything ok.
- We check the loopbacks from metro3000 to MD5500 and found OK.
- This clearly showed that there is some issue on Transmission equipment or media.
- We check the service configurations at METROO3000 & METRO1000, no error found at neither end but service is down.
- Create new service from PQ1 to different SP2Ds and check the loopbacks. No loopback was successful.
- Check the ring status and found that ring is broken between Metro3000 & ONU-28(Metro1000).
- Check the alarms during previous activities and Bit errors observed at service ports. so hard reseted the SD4 card as all SP2D service ports were observing BIP_EXEC alarm but no remedy.
- Change the SD4 card with Spare card, but still recieve BIP errors.
- Ask OSP/OFC team to measure optical power between Metro3000 and ONU-18(Metro1000) and also check for fiber losses.
- OSP team did OTDR testing and find out that pressure is being observed at some distance between Metro3000 and ONU-18(Metro1000) which causing loses in fiber and optical power between the equipments is also quite low.
- Resolution of optical fiber issues, service restored.
- Pressure on fiber and DB losses caused service breakdown.