Installation and Operation Manual
Appendix
E Encapsulation over PSN
ACE-3105, ACE-3205 Ver. 5.2
2BEncapsulation over Different PSN Types
E-3
Control Word
Contains the sequence number and control
bits. 4 bytes long.
Payload
The service data carried on the frame,
depending on the PW type.
MPLS over IP Packet Format
The following figure illustrates the MPLS over IP encapsulation format:
DA
SA
Type
8100
VLAN
tag
Type
800
IP
header
PW
label
Control Word
Payload
Figure
E-3. MPLS over IP Encapsulation Format
Table
E-2. MPLS over IP Parameters
Parameter Name
Purpose
DA
Destination MAC address of the remote
peer or next hop unit. 6 bytes long.
SA
MAC address of the device. 6 bytes long.
Type 8100
If VLAN support is enabled, the Ethernet
packet type is set to 0x8100. 2 bytes long.
VLAN tag
If VLAN support is enabled, this tag includes
the VLAN ID and its priority; configured per
PW. 2 bytes long.
Type 800
IP packet type – 0x800. 2 bytes long.
IP header
The protocol field of the IPv4 header is set
to 137 (MPLS in IP). 20 bytes long.
PW label
Label of the Pseudowire; manually defined
per PW and per direction, or dynamically
learned using LDP. 4 bytes long.
Control Word
Contains the sequence number and control
bits. Optional for some PW types. 4 bytes
long.
Payload
The service data carried on the frame,
depending on the PW type.
MPLS over GRE Packet Format
The following figure illustrates the MPLS over GRE encapsulation format:
DA
SA
Type
8100
VLAN
tag
Type
800
IP
header
GRE
header
PW
label
Control
Word
Payload
Figure
E-4. MPLS over GRE Encapsulation Format
Optional