Fr Dlci To Ethernet Local Switching-Bridged Interworking - Cisco 10000-2P2-2DC Software Configuration Manual

Chapter 21 Configuring L2VPN Interworking
Figure 21-11
FR
CE
FR DLCI to Ethernet Local Switching—Bridged Interworking
This interworking type provides interoperability between Frame Relay attachment VC and Ethernet
attachment VC connected to the same PE router. For this interworking type, Bridged encapsulation is
used, corresponding to Bridged (Ethernet) Interworking mechanism.
•
•
Figure 21-12
Figure 21-12
FR
CE
The PE router automatically supports translation of both Cisco and IETF FR encapsulation types
traveling from the CE, but translates only to IETF when sending to the CE router. This is not a problem
for the Cisco CE router, because it can manage IETF encapsulation on receipt even if it is configured to
send a Cisco encapsulation.
OL-2226-23
Protocol Stack for FR to Ethernet AToM Bridged Interworking—With VLAN Header
FR Link
FR
PE
Q.922 Address
Ctrl (03) Pad (00)
NLPD (80) OUI (00)
OUI (80-C2)
PID (00-07)
MAC Header
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
FCS
In the Ethernet to FR direction, the PE router forwards the Layer 2 packet without any change to the
egress interface, encapsulating the L2 packet over FR using Bridged encapsulation.
In the FR to Ethernet direction, the FR header and bridged encapsulation are discarded and the
L2 packet is sent out with Ethernet encapsulation.
shows the protocol stack for FR to Ethernet local switching (bridged interworking).
Protocol Stack for FR to Ethernet Local Switching Bridged Interworking
FR
PE
Q.922 Address
Ctrl (03) Pad (00)
NLPD (80) OUI (00)
OUI (80-C2)
PID (00-07)
MAC Header
DA
SA
Type/Length
Remainder of
MAC Frame
FCS
MPLS Emulated VC of
Tunnel Label
VC Label
Control Word
MAC Header
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
Ethernet
Eth
CE
MAC Header
DA
SA
Ethertype (81-00)
VLAN Tag
Type/Length
Remainder of
MAC Frame
LAN FCS
Cisco 10000 Series Router Software Configuration Guide
Ethernet/VLAN to Frame Relay Interworking
Ethernet VLAN
Eth
PE
Tunnel Label
VC Label
Control Word
MAC Header MAC Header
DA DA
SA SA
Ethertype 81-00 Ethertype 81-00
VLAN Tag VLAN Tag
Type/Length Type/Length
Remainder of Remainder of
MAC Frame MAC Frame
LAN FCS
Eth
CE
21-19