Simple two man show this week with Ethan & Greg talking through, oh, I don’t know ….. stuff like this
What “best path” means in SD-WAN.
- Traditional “best path” thinking is effective, insofar as it goes. It scales to a large number of devices and destinations. It is resilient. It is mature. However, it has its limitations.
- Routing protocols compute best path for a given destination, not a given application.
- Best path computations are not influenced by real-time events such as lossy links or link congestion.
- In general, lower bandwidth links are not used to carry traffic (i.e. are not computed as the best path and are therefore unused), EIGRP’s variance feature being a notable exception.
Software defined WAN brings a much more sophisticated metric to the computation of best path.
- Best path is computed on a per-application basis, not per-destination. The best path for a bulk traffic application might be different from the best path for a voice application, even if heading to the same destination.
- Real-time link capabilities can be factored into the decision.
- Any link, no matter the available bandwidth compared to other links, can be used in an active/active manner.
- Example: IP Telephony Subnets –
- But the real MAGIC is in the application recognition / selection
- routing by subnets is simplest possible classification
- path selection by application is most complex possible classification
- will we move
Where have all the good staff gone?
What tends to remain behind is the ‘residue’ — the least talented and effective IT engineers. They tend to be grateful they have a job and make fewer demands on management; even if they find the workplace unpleasant, they are the least likely to be able to find a job elsewhere.
Who Needs to Worry About Scale ?
- How many devices make a “large scale network” ? Can you define it ?
- Is it one hundred switches in a data centre ?
- What about one hundred ( or thousand) routers in a WAN ?
- A Corporate Perimeter DMZ that has just 10 devices that are complex to operate and preform deeply complex operations on traffic flows ?
- What about 1 terabit of bandwidth ?
- Is it a million concurrent connections or 10000 connections per second ?
- What about using MPLS to build an overlay network which uses many complex protocols ?
Industry thoughts in 30 seconds.
- Q. What can enterprises do to ensure that their infrastructure is ready for next-gen networking technology implementations emerging in the next decade?
- Q. What networking protocols do you see as growing in importance in 2015?
- Q. What role will cloud and virtualization play in the enterprise data center in the next few years? 1:07 another break
Why SDN in The Enterprise Data Centre Will Take Decades
- Enterprise Data centres are static and change occurs on decade long cycles.
- SDN creates disruptive change to budgets, technical operations, and highlights the failure of existing task frameworks based on ITIL & PRINCE2
- Over-investment in existing assets prevents incremental adoption creating more obstacles to adoption.