I went on a personal “Tech Field Day” this evening and visited Gnodal to talk about their Ethernet switches.
Let me try and summarise my takeaways in bullet points.
1. When you connect their switches back to back they automatically recognise this and “fabric enable” the connection. This fabric connection means you can build Fat-Tree, or multistage Clos, or whatever fabric style suits your network requirements.
1.a Gnodal switches are really, really fast. The interface MAC is embedded in the core chip so there is very few components in the box. This leads to a practical pricing model.
1b. They are shipping three models. GS7200 with 72 x10GBE ports (that’s seventy two 10GbE ports in a TWO RU device.).
There is a GS4008 with is 40 x 10GbE and 8 x 40GBE>
There is a GS0018 with 18 x 40GBE which can be used as an Ethernet switch or as a fabric backbone.
2. This fabric connection uses up to 16 40Gb ports on the switches for multipathing into the fabric.
2a. The internal fabric is lossless and less than 120ns delay.
3. The multipathing algorithm scales linearly past 32 uplinks.
4. They have “frame fairness” concept that ensures all conversations are handled fairly at the Ethernet layer thus removing congestion.
5. They have their own, internally developed ASIC that makes all of the current merchant silicon look like technology from the 1990s.
6. They don’t buffer. Because the fabric is non-blocking, and frame fairness removes congestion points, the switch is much simpler, costs less, and uses less 150W per 1RU. Didn’t believe it until they took the lid off.
7. They do funky multicast handling for low latency forwarding i.e. less 250ns for arbitrarily large switch fabric with multipath and fabric enabled core. (As I understand it).
The EtherealMind View
These guys have built their own chips using design methods that are completely their own. By attacking the fabric problem from a different way ( not unlike, but still different to, Juniper’s QFabric ) they have created something quite unique. And, quite possibly, because they are not in Silicon Valley, have not followed in the same path as the other vendors.
Yes, I’m impressed.If you are a cloud provider, Internet exchange, or had to build a large data centre fabric it’s would be worth taking the time to learn and understand how Gnodal does their stuff and compare it to your current vendors. It’s a new approach that changed my perception of how switching works (and reinforces the QFabric approach that Juniper has taken).
I’m hoping they will come on the podcast in the future to talk in more detail.
You should check it out.