Support for processing of packets received with more than 2 tags on a QinQ SAP in Epipe service (only 
Page 138 7210 SAS M Services Guide
Support for processing of packets received with more than 
2 tags on a QinQ SAP in Epipe service (only on 7210 SAS-M 
network mode)
NOTE: 7210 SAS-M access-uplink mode processes and forwards packets with more than 2 tags. 
Please see the configuration notes in the Services Chapter for restrictions and use of SAPs in 
access-uplink mode. This section is applicable only to 7210 SAS-M in network mode.
To forward packets with 2 or more tags using a QinQ SAP, a new Epipe service type is available 
for use when 7210 SAS-M is operating in ‘network’ mode. This new service will allow for 
configuration of a QinQ SAP as one endpoint and the following service entities as the other 
endpoint:
• MPLS spoke-SDP with vc-type set to vc-vlan.
→ The vc-vlan-tag to be must match the inner-tag VLAN ID value specified in the QinQ 
SAP.
•dot1q SAP
→ The VLAN value configured for the dot1q SAP must match the inner-tag VLAN ID 
value of the QinQ SAP.
The device will process the packet as given below in the forward direction:
• If the packet is received on a QinQ SAP, assign an incoming packet to this service based 
on matching the outermost two tags in the packet header (i.e. in other words the first two 
tags in the packet header). It will strip only the outermost tag (only a single tag) on ingress 
and forward the rest on to the other endpoint in the service (see below). 
• If the other endpoint the packet is sent out of is a MPLS SDP, then MPLS encapsulation is 
added. 
• If the other endpoint the packet is sent out of is a dot1q SAP packet is forwarded as is, 
without any egress VLAN checks. It is expected that operator will ensure that the inner tag 
of the packet matches the dot1q VLAN value.
In the reverse direction, the device will process the packet as given below:
• When traffic is received on the MPLS SDP, the vc-vlan tag is retained as is and the VLAN 
tag corresponding to the outermost tag configured for the QinQ SAP (i.e. the other 
endpoint) is added to the packet. The system does not match the vc-vlan tag received in 
the packet with the configured value (i.e. the inner tag of the QinQ SAP). It is expected 
that operator will configure both end of the service appropriately to ensure only 
appropriate packets enter the service. 
• When traffic is received on the dot1q SAP, the outermost tag is not stripped and the VLAN 
tag corresponding to the outermost tag configured for the QinQ SAP is added to the 
packet.