Figure 58: Access Port Ingress Packet Format And Lookup - Alcatel-Lucent 7750 SR Manual

b. PE-Router-A learns the source MAC address in the packet and creates an entry in the FIB
c. The destination MAC address in the packet is looked up in the FIB table for the VPLS in-
d. If the destination MAC address has already been learned by PE-Router-A, an existing entry
e. PE-Router-A chooses a transport LSP to send the customer packets to PE-Router-C. The
f.
7750 SR OS Services Guide
Customer
Location A
Dest Src VLAN Customer
MAC MAC ID Packet

Figure 58: Access Port Ingress Packet Format and Lookup

table that associates the MAC address to the service access point (SAP) on which it was
received.
stance. There are two possibilities: either the destination MAC address has already been
learned (known MAC address) or the destination MAC address is not yet learned (unknown
MAC address).
For a Known MAC Address
in the FIB table identifies the far-end PE-router and the service VC-label (inner label) to
be used before sending the packet to far-end PE-Router-C.
customer packet is sent on this LSP once the IEEE 802.1Q tag is stripped and the service
VC-label (inner label) and the transport label (outer label) are added to the packet.
For an Unknown MAC Address
If the destination MAC address has not been learned, PE-Router-A will flood the packet to
both PE-Router-B and PE-Router-C that are participating in the service by using the VC-
labels that each PE-Router previously signaled for the VPLS instance. Note that the packet
is not sent to PE-Router-D since this VPLS service does not exist on that PE-router.
PE A
B
IP/MPLS Network
Ingress look-up based on
access port or port/VLAN-ID.
(Figure 59):
(Figure 59):
Virtual Private LAN Services
OSSG202
Page 421