Two Words: Controlled Convergence
If you have been in the networking world for any amount of time over the last decade you have heard of the converged network, traditionally this was thought of as Data, Voice, and Video running on the same network. Obviously each of these have different connectivity requirements and place different strains on the Network. No problem, thats where technology like QoS and traffic policing come in handy, we can help guarantee that real-time latency sensitive traffic like voice receives priority over best effort traffic like web browsing.
Now lets expand on the Data traffic, this was traditionally composed of web browsing, network shares, email, etc. all traffic types that can experience a couple seconds delay in the delievery of IP packets and be just fine, with very few users ever noticing their traffic was delayed. Now enters the Data Center, bringing with it a whole new set of requirements for connectivity, rock-solid performance, lossless delievery of data, high throughput, and low latency and best effort is just not going to cut it. Seems like a clear choice, Fibre channel has been offering this for sometime. Why entertain anything else … $$$$, specialized knowledge, seperate storage network, additionaly equipement to purchase, deploy and manage.
Ok, why can’t we run that traffic on the network we have in place already? Well that traditional ethernet network can not support the new requirements for Data Center traffic, thats where Data Center Bridging comes in. It is not a new form of networking, instead it is an extension to the current Ethernet standards and provides solid performance, lossless delievery, and most importantly seperation of traffic classes over high speed 10 GbE (40 and 100 GbE en-route) network connectivity.
How can it do this? Data Center Bridging is a set of IEEE Standards that is composed of the following.
- Priority Flow-Control (PFC)
- Enhanced Transmission Selection (ETS)
- Congestion Notification (CN)
- Data Center Bridging Exchange (DCBx)
For specifics on each of these check out this Ethernet Alliance White paper explaining the function of each of the standards.
The huge knowledge base, ease of management and wide adoption of Ethernet today combined with the lossless nature of DCB may just provide the justification to move away from a separate Fibre Channel SAN to a true (controlled) converged network. While it seems the first iteration of the DCB implementations are geared toward FCoE (Fibre Channel over Ethernet) many vendors are beginning to support DCB for iSCSI storage traffic.
Who out there has considered using Ethernet or DCB enabled Ethernet for storage deployment?
For more information checkout the following links
