Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 18-44

Switched traffic between similar LANs across a non-trunked or native backbone will have 
translations performed at each egress point. In the figure below, for traffic originating from 
Station A destined to Station B, point 1 represents the ingress (input) port of Switch 1. Like-
wise, point 2 represents the egress (output) port of Switch 1, point 3 represents the ingress 
(input) port of Switch 2 and the point 4 represents the egress (output) port of Switch 2.   
Translations will occur at each egress port. For traffic from Station A to Station B, output 
translations will occur at points 2 and 4. For traffic from Station B to Station A, output transla-
tions will occur at points 3, and 1. 

In the above example, the backbone could be of any media type other than Ethernet. If all 
three media types were Ethernet, then no translations would occur, because the traffic is 
being switched from like media to like media.