5.2 PWE3 Features Supported by the S9300
This section describes the PWE3 features supported by the S9300.
You need to be familiar with the following terms defined in the RFC before you read this section:
l Ultimate PE (U-PE): a PE to which an AC is bound. An AC is directly connected to a U-
PE. The U-PE is the first or last PE of a multi-hop PW.
l Switching Point PE (S-PE): a PE in charge of switching PW labels on a backbone network.
PWs can be classified into the following types:
l Static PW and Dynamic PW in terms of implementation
l SH-PW and MH-PW in terms of networking
Static PW and Dynamic PW
l Static PW
The static PW negotiates parameters without using the signaling protocol. You must specify
the relevant information manually. Data is transmitted between PEs through a tunnel.
l Dynamic PW
The dynamic PW tunnels refer to the PW tunnels that are set up through a signaling protocol.
The U-PEs exchange VC labels through LDP and are bound to the corresponding CEs based
on the VC ID. If the tunnel between the two PEs is successfully set up and label switching
and binding are complete, a VC is set up.
The messages used on a dynamic PW are as follows:
– Request: a message used to request the peer to distribute labels.
– Mapping: a message used to distribute labels to the remote PE. The state bit can be
carried by this message to the remote PE. Whether to carry the state bit is up to
configuration. By default, the state bit is not carried in Martini mode.
– Notification: advertises and negotiates the PW status to reduce the number of messages
to be exchanged.
– Withdraw: a message used to request the peer to delete labels. (It carries labels and state
information.)
– Release: a message as a response for Withdraw. It is used to notify the remote end that
the label is deleted.
Dynamic PW labels are distributed in the outbound and inbound directions.
5 PWE3 Configuration
Quidway S9300 Terabit Routing Switch
Configuration Guide - VPN
5-4 Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Issue 03 (2009-08-20)
To Next Page
Loading...
