Alcatel-Lucent 1643 AMS Applications And Planning Manual page 222

Ethernet Overview
Flexible port role assignment
In most cases physical LAN ports have the customer role and physical WAN ports
have the network role, but there may be exceptions in some applications. In the
following figure the WAN port connects an EPL link and is therefore at the edge of the
TransLAN
LAN
EPL link
In the example in the figure below the VLAN tags have to be forwarded to a router.
The router uses the tagging information for its switch decisions. Additionally the LAN
port must fulfil a network role. In this case it behaves like a node of the TransLAN
network. It could also participate in the STP in order to avoid loops, if there was
another link from a Router LAN interface to a second node within the TransLAN
network.
Router
A LAN port which operates in the "network role" behaves like a WAN port in terms of
VLAN tagging, STP and GVRP.
The default settings are shown in the following table
Customer role
Network role
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11-46
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network. Thus it has the customer role in this case.
TransLAN
LAN unit LAN unit
"Ethernet over SDH"
WAN port ("customer role")
LAN
LAN unit LAN unit
LAN port ("network role")
Port role
Alcatel-Lucent - Proprietary
TM
network
Forbidden acc. to STP
TM
TransLAN
"Ethernet over SDH"
LAN port
default
See notice on first page
LAN unit LAN unit
network
Physical ports
WAN port
default
Port provisioning
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365-312-801R7.2
Issue 3, May 2007