ATM routing/switching
Cell switching is based on routing tables with VPI and VCI entries.
End user
End user
In  
VPI a
VCI d
Out  
VPI b
VCI d
VPI a
VCI d
VPI b
VCI d
VPI c
VCI e
In  
VPI b
VCI d
Out  
VPI c
VCI e
ATM network
switching at virtual path level     ... virtual channel level