LAN WAN -- figures /performances see the difference
store-and-forward
virtual curcuit :Telephone system
datagram :Postal system
route is established;store-and-forward sheme;vc number need to be carried by a packet
intermediate nodes contain a table created during route establishment
independent entity, no garantee; route dynamically decide the next node
out of order; a node crashes queued packets lost; duplicate
faster,flexible,handle congestion/failed links
原文：http://www.cnblogs.com/yumanman/p/7582303.html