Filter
Top Products
21-8
Cisco 10000 Series Router Software Configuration Guide
OL-2226-23
Chapter 21 Configuring L2VPN Interworking
Ethernet/VLAN to ATM AAL5 Interworking
Figure 21-2 Protocol Stack for ATM to Ethernet AToM Bridged Interworking—With VLAN Header
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.
• 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.
Figure 21-3 shows the protocol stack for ATM to Ethernet local switching -bridged interworking. The
ATM side has an encapsulation type as aal5snap.
270309
ATM
CE
ATM
PE
Eth
PE
Eth
CE
ATM Ethernet VLANMPLS Emulated VC of
ATM Header
MAC Header
DA
SA
MAC Header
Control Word
Tunnel Label
VC Label
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
Remainder of
MAC Frame
CPCS - UU CPI
Length
CRC
LLC (AA-AA)
LLC(03) OUI (00)
OUI (80-C2)
PID (00-07)
PAD (00-00)
MAC Header
Control Word
Tunnel Label
VC Label
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
MAC Header
DA
SA
Ethertype 81-00
VLAN Tag
Type/Length
Remainder of
MAC Frame
LAN FCS