Cisco ASR 920 series

Scenario 2 - 2:1 VLAN Translation
Figure 6: 2:1 VLAN Translation
The above scenario depicts an instance of a local E-Line service, with one AC (AC1) with double VLAN ID
(inner 100 andouter 10) and the other AC (AC2) with VLAN ID (30). The frame with CoS=3 from the inner
VLAN 100 in AC1 has to be delivered in AC2 with VLAN 30 and CoS=3. Similarly, for remote instance, we
have AC (AC3) with VLAN 50 and same inner CoS 3 should be transparently carried over MPLS cloud to
AC3 from AC1. The way we can achieve this behavior on ASR903 is with 2:1 VLAN translation command
on service instance connected to AC1.
In this particular scenario, since there is a inner Tag present, inner CoS will be propagated in the newly added
Tag to both CPE2 and CPE3 ACs.
Limitations for VLAN Translation with QoS
•
Only 1:1 and 2:1 translate rewrites are supported in Cisco IOS XE 3.17 release. 1:2 and 2:2 translations
are not supported.
•
Translate operation can only be applied to a unique tag matching service instance.
•
VLAN Translation is not supported on TEFP, encapsulation untagged, and BDI interfaces.
•
Any VLAN Translation with rewrite pop2 is not supported.
•
Translation is only supported for 802.1Q (0x8100) encapsulation.
•
Translation is not supported for 802.1AD (0x88A8) and Customer Ethertype (0x9100 and 0x9200).
•
Egress QoS policy is not supported on Trans 2:1 and 1:1 VLAN Translation, if ingress Translation or
push EFPs do not have policy.
•
For 1:1 to 1:1 scenario, marking is not supported.
•
Ingress POP 0 or 1:1 CoS marking is not supported.
Carrier Ethernet Configuration Guide (Cisco ASR 920 Series)
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VLAN Translation with QoS
Limitations for VLAN Translation with QoS