Network design, architecture, thinking, working. Tech.
A couple of weeks back I posted this article comparing pricing and features on Cisco Fabric Ethernet Transceivers as a low cost option compared to 10GbaseSR SFP+ optics in when building 10GbE networks – Cisco Nexus 5000 / 2000 Pricing Bundles and Fabric Extension Transceivers (FETs) vs 10GbaseSR SFPs.
I was reading a white paper by Panduit that claims that 10GBaseT is suitable for use. I’ve been critical of Cat6A cable and believe that it’s not suitable for data centre use.
With all the talk about Layer 2 Multipath (L2MP) designs going on, I just want to point out a fundamental change in the way many people approach network design. It’s seems that this point has been lost somewhere in the discussion of protocols.
The Spanning Tree Protocol blocks looped paths, and in a typical networks this means that bandwidth is unevenly distributed. Of course, we might use PVST or MST to provide a rough sharing of load by splitting the spanning tree preferences for different VLANs, but the design still doesn’t change overall. The basic point is that there is a LOT of bandwidth that is never evenly utilised – and that means wasted power, space and cooling (which costs more than the equipment itself).
I was doing a Data Centre Design recently and did some numbers around the numbers of 10 Gigabit Ethernet ports that need to be deployed. I got a bit of a realisation shock.
I tweeted “an I haz a “I ♥ OpenFlow” sticker pleez” – just got a call….
Someone made a comment that Packet Pushers hasn’t discussed SPB as alternative to TRILL or other Fabric solutions. Here’s why.
Kurt Bales has a customer who wants to buy a new Data Centre Network and the three main networking vendors (Juniper, Cisco & Brocade) have pitched at him and the customer. Kurt then contacted the Pushers and said “This would make a great podcast to talk about how it looks, works and the reality of the so-called “Data Centre Fabric networks, plus I’ve got some questions that I’d like to get some second opinions.”
So we rounded up Ivan from IOS Hints and Greg from EtherealMind to record a fast, furious and focussed look at the state of play with the three data centre fabrics today. Lots of speculation, wild guesses and deep diving followed. I learned heaps.
Breaking down the definition of North/South and East/West Bandwidth with some nice pictures and examining Layer 2 Multipath and why it fits virtualisation so well.
I was intrigued and excited about the Junipers announcement last week of QFabric. I was vaguely aware of TRILL and Cisco implementation (Fabric Path), but came to the table (so to speak) with no pre-conceptions of what I might expect. SCI-FI ñ Is this just me? Is the ëQí in †QFabric taken from sci-fi [...]
The current technologies of data centre networks don’t address the fundamental scaling issues. You can’t scale to hundreds of independent switches, we need to have less control planes for more coherent functions. Here is my take on next wave of networking in the data centre beyond DCB and TRILL.
