Sometimes, marketing buzz is really good at creating confusion in people's mind - One may even wonder if it is not its main goal...
I was recently invited to meet the IT infrastructure team of a semi-public organization in a central European country. Let's call it Syldavia (http://en.wikipedia.org/wiki/Syldavia). It is a two or three hundred miles wide country with a few million inhabitants. It is a well organized country, with handsome, friendly and highly educated people. The organization that invited us is in contact with the public. In a nutshell, it runs a network of two datacenters and a few hundreds of branch offices located in Klow (Syldavia's capital) as well as in cities and villages all across the country. The purpose of the meeting was to discuss the various solutions to provide good and sustainable performance to their business applications running at branch offices and hosted in the datacenter.
The first question that raised was: "how could we solve our delay problem?". I must recognize I remained puzzled for a while: Syldavia is a really great country, but certainly not a large one. The maximum distance between datacenters and offices is about 300 kilometers: 1 millisecond at speed of light. Okay, networks are much slower than light (approximately half speed), and we need to add access modems (SDSL in this case); but I doubted the total delay could be much larger than 10ms.
Fortunately, I remembered that Bordurian spies (http://en.wikipedia.org/wiki/Borduria) made a recent attempt to brainwash our Sylvanian friends, using the old good FUD (fear, uncertainty, doubt) tactic: delay here, delay there, everything is about delay, solve this delay problem or you are a stupid manager, etc...
A more objective discussion demonstrated easily that delays, if any, would be caused not by distance but by congestion: saturated device buffers would easily store a few seconds of traffic, leading to poor user experience at branches. Congestion avoidance technologies (like traffic priorization, redundancy elimination or bandwidth upgrades) are then better suited than brute-force acceleration boxes.
To solve this situation, it is clear that a few well-located devices (in data centers and possibly some main offices) would guarantee good and stable performance for all business applications at a much lower cost than deploying Bordurian devices at every branches, with all its associated complexity and cost: it is then possible to satisfy both users and CFO at the same time.
Could I urge you to resist to Bordurian's intelligence services?
Delays are not the root cause of performance, they are symptoms. Real root causes of poor user experience over networks are:
- Geography: distance of long haul networks --> Delays (in the core network) --> Impact chatty applications only --> Protocol acceleration
- Lack of bandwidth (or excess of traffic) --> Congestions --> Delays (in network devices) --> Impact all applications --> QoS, compression, bandwidth upgrades
Viva Syldavia!