| Costs
				The simplicity of the telephone exchange protocol comes at a price:
				 
					If a switch in the core crashes, the routing protocol 
					doesn't know how to find an alternative path. 
					Therefore, to make the system as a whole reliable,
					every switch must be reliable.
					
					Requiring every pair of switches to be connected by a one-hop logical trunk makes for 
					a network that is expensive to create and to maintain.
					
 
				An alternative would be to develop a network where sophisticated
				routing algorithms lower the requirements for connectivity by allowing
				the removal of some of the direct links.
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