Network requirements

For many years, data center networks have been built in layers that resemble a tree. As this hierarchy runs up against limitations, a new model is taking its place.

In the hierarchical tree data center, the bottom of the tree is the access layer, where hosts connect to the network.

The middle layer is the aggregation, or distribution, layer, to which the access layer is redundantly connected.

The core layer provides routing services to other parts of the data center, as well as to services outside of the data center such as the Internet.

This model scales somewhat well, but it is subject to bottlenecks. This can come from latency incurred as traffic flows through each layer and from blocking of redundant links.

In modern data centers, an alternative to the core/aggregation/access layer network topology has emerged known as leaf-spine. In a leaf-spine architecture, a series of leaf switches form the access layer. These switches are fully meshed to a series of spine switches.

Leaf-spine architectures can be layer 2 or layer 3, meaning that the links between the leaf and spine layer could be either switched or routed.

In a layer 2 leaf-spine architecture, spanning-tree is most often replaced with either a version of Transparent Interconnection of Lots of Links (Trill) or shortest path bridging (SPB).

We would choose the Switches from Juniper ‘QFabric System’. The QFabric System is composed of multiple components working together as a single switch. It flattens the network to a single tier to provide high-performance, any-to-any connectivity and management simplicity, making it the ideal network foundation for cloud-ready, virtualized data centers.

http://www.juniper.net/us/en/products-services/switching/qfabric-system/