Appendix
E Encapsulation over PSN
Installation and Operation Manual
E-4
2BEncapsulation over Different PSN Types
ACE-3105, ACE-3205 Ver. 5.2
Table
E-3. MPLS over GRE Encapsulation 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 47 (GRE). 20 bytes long.
GRE header
The Protocol Type field of the GRE header is
set to 0x8847 (MPLS). 4 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. 4 bytes long.
Payload
The service data carried on the frame,
depending on the PW type.
MPLS Packet with/without PHP
The following figures illustrate the MPLS packet format with and without PHP (for
more information, refer to
Chapter 1
).
PHP Disabled – Control Packet
DA
SA
Type
8100
VLAN
tag
Type
8847
Tunnel
label
IP header
UDP
LDP
Figure
E-5. MPLS Control Packet when PHP is Disabled
Table
E-4. Encapsulation 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.
Optional
