Atm Aal5 To Ethernet Local Switching-Bridged Interworking - Cisco 10000-2P2-2DC Software Configuration Manual

Ethernet/VLAN to ATM AAL5 Interworking
Figure 21-2
ATM
CE
ATM AAL5 to Ethernet Local Switching—Bridged Interworking
This interworking type provides interoperability between Ethernet attachment VC and ATM attachment
VC connected to the same PE router. For this interworking type, Bridged encapsulation is used,
corresponding to the Bridged Interworking mechanism.
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•
Figure 21-3
ATM side has an encapsulation type as aal5snap.
Cisco 10000 Series Router Software Configuration Guide
21-8
Protocol Stack for ATM to Ethernet AToM Bridged Interworking—With VLAN Header
ATM
ATM
PE
ATM Header
LLC (AA-AA)
LLC(03) OUI (00)
OUI (80-C2)
PID (00-07)
PAD (00-00)
MAC Header
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
CPCS - UU CPI
Length
CRC
In Ethernet to ATM direction, the PE router forwards the Layer 2 packet without any change to the
egress interface, encapsulating the Layer 2 packet over AAL5 using Bridged encapsulation.
In ATM to Ethernet direction, the ATM header and bridged encapsulation get discarded and the
Layer 2 packet is sent out with Ethernet encapsulation.
shows the protocol stack for ATM to Ethernet local switching -bridged interworking. The
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
Chapter 21 Configuring L2VPN 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
OL-2226-23