Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

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remove the S-VLAN tags from all packets entering the circuit. A device or network is said
to be S-VLAN-aware, if the packets passed through it contain the S-VLAN tag configured
on the subinterface. Similarly, if the S-VLAN tag is not configured on the subinterface,
the device is said to be S-VLAN-unaware of the packet reaching it because the S-VLAN
tag is not passed to it.
A particular S-VLAN tag that is identified as the service-delimiting tag is removed from
the incoming Ethernet frame from the CE device before it is sent on the pseudowires. In
this release, only raw mode operation is supported on the S-VLAN subinterfaces of PE
routers. Therefore, scenarios in which the S-VLAN tag is made available to the MPLS
network and the S-VLAN tag is not advertised to the the CE device are not supported.
Depending on how Ethernet raw mode is configured on PE devices and the configuration
of the S-VLAN subinterface on CE-facing devices, a device in the Maritni circuit can be
either S-VLAN-aware or S-VLAN-unaware.
Figure 124 on page 554 shows a Martini circuit deployment in which the CE-side devices
on either side of the network send and receive Ethernet frames. The packets reaching
the CE-side devices can be S-VLAN-aware or not. The MPLS network might also be
S-VLAN-aware or not, which means that S-VLAN tags might or might not be sent over
the MPLS cloud.
Figure 124: MPLS L2VPN Tunnel over LAG Configuration Example
PE1 CE1 CE2 PE2
MPLS network
Ethernet traffic
g016510
Ethernet traffic
Martini tunneling
Pseudowire
The cases in which the MPLS network is S-VLAN-aware, but the CE-side device is not
S-VLAN-aware, are supported because the Ethernet pseudowire operates in tagged
mode. When the pseudowire is configured for raw mode, only two cases are supported:
whether the CE-side device is S-VLAN-aware or not aware.
Table 101 on page 554 describes the different scenarios in which the Martini circuit shown
in Figure 124 on page 554 can be deployed depending on whether the various network
segments are S-VLAN-aware or not.
Table 101: Martini Circuit Scenarios Without Ethernet Raw Mode
Whether scenario is
supported, when raw
mode is not
configured on the
S-VLAN interface
Receiving CE
Device (CE2)
MPLS network
between local and
remote routers, PE1
and PE2
Sending CE device
(CE1) Case
number
Supported S-VLAN-Aware S-VLAN-Aware S-VLAN-Aware 1
Unsupported S-VLAN-Aware S-VLAN-Unaware S-VLAN-Aware 2
Copyright © 2010, Juniper Networks, Inc. 554
JunosE 11.2.x BGP and MPLS Configuration Guide