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QinAny Mode

First of all the thing which is to be noted is that the QinAny mode is only supported by the Cisco XR 12000 Series Router.

Actually the QinAny mode is just like the or maybe you can call that it is similar to the QinQ mode using Type 5 virtual connection (VC), instead of that the customer edge VLAN (inner) tag will be carried into the packet while it is sent over the psedowire. This is just because the customer edge VLAN (inner) tag is not known by the configuration.

Basically in the QinAny mode, the service provider VLAN (outer) tag is configured on both the ingress as well as the egress nodes of the provider edge VLAN. [click to continue…]

Ethernet Port Mode

Ethernet Port Mode:

In this mode both the ends of the pseudo wire (PW) are connected to the Ethernet ports. The port is tunneled pseudo wire (PW) or using local switching. This is also known as AC-to-AC cross connect) switches packets or frames from one AC to another AC are attached to the same PE node.

The pseudo wire is always a type 5 virtual connection (VC).

On the Ingress Provider Edge, the network service provider passes the packets to the pseudo wire termination point, and adds the MPLS (learn MPLS basics) labels to the packets, and sends the packets over the pseudo wire. [click to continue…]

Layer 2 VPN

L2VPN Concepts:

Layer 2  VPN emulates the behavior of a local area network (LAN) across an internet protocol (IP) or MPLS-enabled IP network allowing Ethernet devices to communicate with each other as if they were connected to a common LAN segment.

Internet service providers (ISPs) would like to replace their Frame Relay (FR) or Asynchronous Transfer Mode (ATM) infrastructures with an IP infrastructure. Accordingly, there is a need for to provide standard ways of using an IP infrastructure to provide a serviceable L2 interface to customers, specifically, to provide standard ways of using an IP infrastructure to provide virtual circuits between pairs of customer sites. [click to continue…]



In the past the old days we have layer 2 virtual circuits provided courtesy of our service provider
A virtual circuit would be an overlay normally from side A to side B. may be a frame lay link or ATM or SMDS, X.25 whatever it is. It is the overlay of the provider network.
If you have multiple sites you have full mesh, partial mesh, multilevel topology etc.
We also have overlay methods of IP Tunneling in which we have IPsec, GRE, and PPTP.
IPsec and PPTP has the benefit over GRE is the security but they doesn’t have the encryption.
So the GRE benefit is that of encryption. [click to continue…]