News

Route-redundant direct connection via dark fiber

Just over four years ago, our second cloud site in Lupfig (Canton Aargau) became operational in order to enable geo-redundant setups for our customers. So that virtual servers would be able to communicate directly between the two sites without the data traffic leaving our network, we connected the sites using dark fiber. This means that instead of simply purchasing transmission capacities from a third-party provider, we rent unused "dark" glass fiber lines and use our own transceivers to "illuminate" them ourselves at the endpoints.

To achieve greater total capacity, we use coarse wavelength division multiplexing (CWDM) where laser light with different wavelengths (also known as "colors" in everyday parlance) is transmitted over one and the same glass fiber line. On one of these channels, we connected the core routers of our two sites with 10 Gbps, while two others, bundled together to 20 Gbps, used to connect the locations at switching fabric level.

For maximum availability, we duplicated the physical connection. The sites in Rümlang and Lupfig are connected by separate dark fiber lines on different, non-intersecting routes. This means that the connection remains available even if one of the fiber lines is damaged, e.g. during roadworks. Even within the data centers, we paid attention to detail with our cables entering the buildings via separate entrances, not intersecting after this point either and terminating in different racks. This redundancy allowed us to double the normally available capacity to 2x 10 Gbps between the core routers and to 4x 10 Gbps between the switching fabrics.

Upgrade to 2x 100 Gbps

We recently significantly extended the connection between the switching fabrics: instead of 2x 10 Gbps there are now 100 Gbps available on each of the separate routes. By adapting the data rate to the one used inside the sites, less buffering is required, which further reduces latency of data transmission.

The connections between the sites at switching fabric level are used, among other things, for data traffic between your virtual servers. This means that you automatically benefit from this upgrade if you, for example, periodically save an archive copy of your data off-site.

Outlook

The upgrade of the connections to a total of 2x 100 Gbps will generally benefit all those applications where relatively large quantities of data are exchanged between our cloud sites. In addition to increased "breathing space" for existing setups, the extended capacity also creates a foundation for future features such as off-site back-up of our customers' data.

At cloudscale.ch, we use redundancy at every level to avoid failures whenever possible. However, we nonetheless recommend that our customers make the most of the full potential of both our sites and create their setups in a geo-redundant manner. The recently significantly extended direct connection between our sites has also created a basis for rapid and reliable replication of your data.

A common definition states that the "cloud" is based on the three pillars of compute, storage and network. Although it is often the most inconspicuous of the three, the network is decisive – not only for standard operations, but in particular with regard to geo-redundancy. With our upgrade to 2x 100 Gbps between the two cloud regions Rümlang and Lupfig, you can build on a solid foundation, today as well as tomorrow.

Looking ahead,
Your cloudscale.ch team