80/20 rule

datchcha

Can someone explain the 80/20 rule in a network model? I can not seem to grasp this rule or concept.

thank you

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Comments

Netstudent

80% of single woman are gold-diggers, and the other 20% are lying.

but really, 80% of traffic should stay local while 20% should cross the core switches. Thats the way I have read it anyways. This can vary in the real world I'm sure. Who goes by the rules?

ITdude

Except for the first one you mentioned!

Only kidding ladies!

Darthn3ss

ITdude wrote:

Ecept for the first one you mentioned!

no thats true too!

dtlokee

Yeah, Netstudent has it right. Today's models are slightly different because many companies are now consolidating their servers into farms that are centralized and connected somewhere to the distribution layer and usually requires crossing the core, as opposed to the old model where servers were workgroup oriented and connected to the access layer or locally to the distribution layer. The new model requires much higher speed WAN connections than the previous designs.

jediknight

Netstudent wrote:

80% of single woman are gold-diggers, and the other 20% are lying.

Wish I'd known this a long time ago... I'd have more money for Cisco Hardware.

Netstudent

Ya for any ladies around, that was a joke, no disrespect intended.

Rearden

In reality, it doesn't happen much. For example, I work at a college campus and most traffic is Internet bound.

mikej412

The old 80/20 rule is that 80% of the traffic was local and only 20% of the network traffic went over the backbone. This goes all the way back to 2Mb Arcnet, 10Mb Ethernet hubs, 16Mb Token Ring... etc -- back to the dark ages of networking.

With the advent of the Internet, WANs, enterprise servers, switched networks, etc -- that's swapped. You can look at it as the 20/80 rule or the new 80/20 rule - with the 20% being local (same subnet or VLAN) and the other 80% going through a router (or layer 3 switch).

Netstudent wrote:

that was a joke

If you want to hear something really funny -- there was a time when the 80/20 rule was applied to VLANs as switched networks were being developed. The networks were supposed to be engineered so that 80% of the traffic would stay in the VLAN.

The funny part of that -- some people took that to mean global layer 2 switched networks -- with broadcasts from a salesman's PC in Tokyo going over the ATM links between switches to every other location in the world that had salespeople. Toss in STP and traffic "going backwards" around the world from the UK (through the US, Tokyo, Sydney, etc) to reach Germany -- now that was hilarious (winter of '98/'99 if I recall correctly).

Then came the deployment of layer 3 switching (wire speed routing) -- and it was good.

datchcha

thanks guys...understand now.