Upp network Kings Lynn to Fakenham link down on Smartoptics DWDM

On this fault we got a report of a link between two sites, the report was to check connection from Kings Lynn North to Fakenham.

The link consisted of a Nokia 7750 aggregation core router in Fakenham feeding OLT HNST-X-UA NTB and from Downham Market another aggregation router feeding Hunstanton OLT HNST-X-UA NTA port via Kings Lynn.

The Upp NOC reported that they lost the uplink to Hunstanton OLT HNST-X-UA port NTB. This was a loss of redundancy only.

Upon arrival we engaged a teams call. I could see on the Smartoptics kit that we had no uplink on the DCP-404 similar Infinera FXP400G-E line card. This is the same as having a client port down on a Infinera FXP400G-E card.

With the NOC double checking that nothing in the software was causing the outage, I proceeded to test the cabling, this was determined to be the amplified line port from Fakenham towards Hunstanton OLTs.

I tested both legs of the cable with my OTDR and we found one of the legs testing shorter that the other one. Due to the location of the damage it was decided to use a spare port linking Fakenham to Hunstanton. I then proceeded to test a spare port with my OTDR and verified a good pair of fibers linking both sites. We then proceeded to move the cabling at Fakenham to the new ports and I then drove to Hunstanton and moved the fibers to the relevant equivalent port.

With this we were able to get the link back up and working and checking in the equipment and with the help of the NOC we got uplink between aggregation router and OLT up. There was some adjustment of attenuation values as the new pair of fiber ports where better than the damaged ones.

The call was then closed of and all records updated to reflect the new port that was used to link sites.

This then restored the redundant uplink so we would not have a full outage to customers and business.