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Communication Tower
Edging in on the Core
What is the "edge" vs. "core" of a network?

It might be helpful to give the reader some definition of the word “core” of the network, the internal infrastructure, versus the “edge”. Simplistically, the edge network refers to the end-points and the first hop from the end-points into the “center” or core of the network. In enterprise, the end-points are PCs, including their associated adapters, and modems for connecting to carriers, and various connected devices.  The edge network today also includes WiFi access points, and desktop and wiring closet switches. Datacenters have the edge networks in racks that aggregate server traffic. The core of the network is often in the data centers. The edge resides in the wiring closets.


The backbone or core network then connects the various zones within the datacenter and to other datacenters, with switches and routers. Networking in the ‘90s had grown from the edge to the center or core. This explains how Cisco dominated with the big chassis, heavy metal approach commonly seen with their core routers and switches, which permits more dense connectivity – more connected and networked devices. The complexity of the core network comes from all the controls needed to steer the packets from the IP routing all the way up to the user, including key aspects like security.


In 3Com’s case – NetBuilder II was closer to a core device, while boundary routing software would assist with edge.  Synernetics switches were in the core as well, relying on an FDDI backbone technology, which lost out later to Fast Ethernet as it developed and was standardized and supersized more rapidly by Cisco.  NiceCom was developing an ATM switch for the backplane/ core and Chipcom, a hub company, was acquired with the idea that they were privately developing a backplane, which turned out to be false after the deal closed (Chipcom was a public company – not all was divulged in the due diligence). 


As Fast Ethernet took off when the standard was approved, Cisco’s switches from its Crescendo acquisition, running on Fast Ethernet standardized by Grand Junction and others, began capturing the core, along with Grand Junction’s desktop switching, capturing more the edge, and flew by 3Com. 3Com had gone all in with Synernetics, an FDDI based ethernet switch (before the Fast Ethernet standard emerged), and moved then onto ATM (via the Nicecom acquisition) for the "backbone", which turned out the wrong bet.  3Com’s success in the edge, with smaller form factor hubs, switches and routers, left Cisco, and earlier Wellfleet/ Bay Networks, to capture the big chassis, core devices, which ended up being first and foremost front and "center" to CIOs and their enterprises. Ironically, Grand Junction’s (founded by a 3Com founder Charney and 3Com alumn) earlier development of Fast Ethernet contributed to their rapid acceleration.

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