Definition Series: Data center network topology with leaf-spine architecture

Today the information age is coming back to the definition series with tech target website WhatIs.com. This time with a post on the important and currently hot subject of data centers. Data centers had become a very important business topic, for obvious reasons. The current relevance of Big Data, Data engineering/management and related topics does not show signs of abating anytime soon; so everything to with these topics is worth our attention.

Data centers are even a commercial real estate hot topic. Add to this the advanced science and engineering jobs and tasks around this and the picture is one of bright spots for the global economy. What current economic sector blend capital-intensive activities with high value creating highly skilled jobs and tasks ? Difficult to find , really…

 

508px-networktopologies-svg
Diagram of different network topologies (Wikipedia).

The post at WhatIs.com is a further stretch of our imaginative minds by combining the topic of data centers issues with the important scientific topic of network topology. We read through the post and are reminded of other scientific topics such as complexity theory, decision trees or concepts in neuroscience. But behind the concepts is not an empty bucket, no. This is really related to how data center network topology really works. Exciting blend of all-encompassing engineering and economic topics for a business consultant near you to think about… Enjoy:

leaf-spine (leaf-spine architecture)

 

Leaf-spine is a two-layer data center network topology that’s useful for data centers that experience more east-west network traffic than north-south traffic. The topology is composed of leaf switches (to which servers and storage connect) and spine switches (to which leaf switches connect). Leaf switches mesh into the spine, forming the access layer that delivers network connection points for servers.

 

Every leaf switch in a leaf-spine architecture connects to every switch in the network fabric. No matter which leaf switch a server is connected to, it has to cross the same number of devices every time it connects to another server. (The only exception is when the other server is on the same leaf.) This minimizes latency and bottlenecks because each payload only has to travel to a spine switch and another leaf switch to reach its endpoint. Spine switches have high port density and form the core of the architecture.

 

A leaf-spine topology can be layer 2 or layer 3 depending upon whether the links between the leaf and spine layer will be switched or routed. In a layer 2 leaf-spine design, Transparent Interconnection of Lots of Links or shortest path bridging takes the place of spanning-tree. All hosts are linked to the fabric and offer a loop-free route to their Ethernet MAC address through a shortest-path-first computation. In a layer 3 design, each link is routed. This approach is most efficient when virtual local area networks are sequestered to individual leaf switches or when a network overlay, like VXLAN, is working.

 

Body text image: Network Topology Wikipedia page

featured image: leaf-spine (leaf-spine architecture)

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