One of our third-party providers has advised that they need to perform an urgent at risk maintenance at Goswell Road (GOS) which could impact our Dark Fibre link from Goswell Road (GOS) to Telehouse North (THN).
During this maintenance, we will have periods of reduced resiliency.
The third party will be splicing new fibres in ducts, this is a part of a wider project to improve existing service between their datacentres.
Custodian’s networking team will be working closely with the third party at all times.
[Layer-3 IP Transit Services] Our core IP Transit network automatically re-routes all protected services when a fibre break is detected, and brings the failed fibre back into service only once it has been stable and error free for a period of time. As such, all Layer-3 services will have possible path switches at start and end of this work, depending on destination path selected, with potential changes in latency to some destinations, no significant disruption is expected to any IPT services at any location.
[Layer-2 MPLS/VPLS Services] Standard Ethernet Services which have a path between GOS<->THN may experience an outage.
Protected Ethernet Services which have a path between GOS<->THN may see a switch/re-route during this work; no significant disruption is expected.
Diverse Ethernet Services which include a path between GOS<->THN may see the loss of one member; no parallel outages of both feeds are expected.
[Wavelength Services] Services between GOS<->THN may experience an outage.
This maintenance has been scheduled under ticket: [CDC-ID: #236757]
Custodian engineers will be upgrading and replacing core DWDM optical transport equipment at one of our sites under ticket #237059.
This is to increase the performance of wavelength solutions between sites.
[Scope] This notification is for essential upgrade works which will impact services TRAVERSING our London PoPs listed below. Affected services will be offline during the window, for approximately 30 minutes while engineers remove and replace DWDM equipment on our dark fibre network. Any rollback requirement will extend this time.
Affected PoPs: GOS/SOV/MER/GS2/THN
[Impacted Services] Wavelength services traversing any of the affected PoPs listed above will be impacted. For Diverse wavelength services, only one service will be impacted at a time.
Unprotected Layer-2 Services traversing sites listed above will be impacted. Protected Layer-2 Services traversing sites listed above will see a brief sub-second loss whilst they reroute.
Diverse Layer-2 Services traversing sites listed above will see an impact only on one of the two interfaces.
IP Transit services are not directly impacted, but may see path/latency changes during core convergence events.
[Additional Clarifications] Direct services from CDC to THN and from CDC to GOS are not impacted by this maintenance. Services traversing the PoPs listed above, for example, going to 4D in Byfleet or Gatwick, will be impacted.