Table 11: Sap Bpdu Encapsulation States - Alcatel-Lucent 7210 Sas-x Service Manual

Configuring a VPLS Service with CLI
Operationally Forwarding
Configuration BPDUs are sent out a SAP in the forwarding state. Layer 2 frames received on the
SAP are source learned and destination forwarded according to the FIB. Layer 2 frames received
on other forwarding interfaces and destined for the SAP are also forwarded.
SAP BPDU Encapsulation State
IEEE 802.1d (referred as dot1d) and Cisco's per VLAN Spanning Tree (PVST) BPDU
encapsulations are supported on a per SAP basis. The STP is associated with a VPLS service like
PVST is per VLAN. The difference between the two encapsulations is in the Ethernet and LLC
framing and a type-length-value (TLV) field trailing the BPDU.The encapsulation format cannot
be configured by the user,the system automatically determines the encapsulation format based on
the BPDUs received on the port.
The following table shows differences between Dot1d and PVST Ethernet BPDU encapsulations
based on the interface encap-type field:

Table 11: SAP BPDU Encapsulation States

Field
Destination MAC
Source MAC
EtherType
Dot1p and CFI
Dot1q
Length
LLC DSAP SSAP
LLC CNTL
SNAP OUI
SNAP PID
CONFIG
TLV: Type & Len
Page 310
dot1d
encap-type null
01:80:c2:00:00:00 01:80:c2:00:00:00
Sending Port MAC Sending Port MAC
N/A 0x81 00
N/A 0xe
N/A VPLS SAP ID
LLC Length LLC Length
0x4242 0x4242
0x03 0x03
N/A N/A
N/A N/A
Standard 802.1d Standard 802.1d
N/A N/A
dot1d
encap-type dot1q
7210 SAS-X, R6 OS Services Guide
PVST
encap-type encap-type dot1q
null
N/A 01:00:0c:cc:cc:cd
N/A Sending Port MAC
N/A 0x81 00
N/A 0xe
N/A VPLS SAP encap value
N/A LLC Length
N/A 0xaaaa (SNAP)
N/A 0x03
N/A 00 00 0c (Cisco OUI)
N/A 01 0b
N/A Standard 802.1d
N/A 58 00 00 00 02
PVST