TTB Loss of Service Thursday 8th April 2021 12:43:08 am

TTB have notified of a potential network issue affecting a small number of services, leading to no or limited service.

We will update as soon as we have further information.

This issue is now resolved and TTB confirm clear.

At 22:23, IOC identified a drop in light on the Huawei DWDM (Dense Wavelength Division Multiplexing) which impacted on Voice also.

All alarms had cleared shortly after on the Huawei DWDM, however we were still seeing impact on the Core Network at 22:45 where it was identified a disturbance on the DWDM Core Network (we were still getting reports of services still being down).

Core Networks had then been engaged and had identified an issue on p (Core Router) in Manchester science park who had raised this with Juniper.

As of 01:42, Core Networks had advised that circuits were then starting to come back up where IOC and Service Assurance teams had advised a number of "up" alerts had been seen however Core Networks advised we still had issues on one core, the rest of the nodes had then recovered (only that one box had issues).

As of 02:15 confirmation that last core was also back up. Core Networks had advised that in order to restore service, they carried out a switchover on the node to recover. Root cause was due to a flap on DWDM which caused issues on the nodes, however RCA will be with Juniper to investigate. The incident will now be resolved as all systems are available with no further issues reported. Monitoring will remain in place to ensure stability.

TTB have identified the issue due to a fibre disturbance in their network. This would be a physical disturbance such as a cable break.

At this time, we do not have any further information but will update as soon we know more.