EoMPLS on 7600 : PFC-based, SVI-based, Scalable

With the "recent" addition of the ES/ES+ cards (although some SIP cards might belong in the same category), 7600 can now support 3 types of EoMPLS configurations . Depending on your needs and the available hardware, you will find at least one between them that can help you implement your network design.

PFC-based EoMPLS
This is the most well-known EoMPLS that is configured under a physical interface or subinterface using the xconnect command. Label imposition/disposition is being done by either the SUP's PFC or the ingress module's DFC, so it's supported on all the usual LAN (i.e. 67xx) cards.

You can use it for point-to-point L2 services between single attachment circuits, where you do not require any local switching or mac-address learning. Each local attachment circuit uses a single EoMPLS pseudowire to connect to a single remote attachment circuit.

Local Router

int Gi1/1
 xconnect 1.1.1.2 10 encapsulation mpls

int Gi1/2.20
 encapsulation dot1q 20
 xconnect 2.2.2.2 20 encapsulation mpls

Remote Router

int Gi1/1
 xconnect 1.1.1.1 10 encapsulation mpls

int Gi1/2.20
 encapsulation dot1q 20
 xconnect 2.2.2.1 20 encapsulation mpls

SVI-based EoMPLS
This EoMPLS is configured under a vlan (SVI) interface using also the xconnect command. Label imposition/disposition is being done by the egress module (where the EoMPLS VC points to), so it must be either a SIP or an ES/ES+ based one. Also there is a limitation that you must have a L3 (sub)interface as the egress interface where the EoMPLS VC will pass through.

You can use it for point-to-point L2 services between multiple attachment circuits, where you also require local switching and mac-address learning. It's like a mini VPLS implementation, where multiple local attachment circuits use a single EoMPLS pseudowire to connect to multiple remote attachment circuits.

Local Router

int Gi1/1
 switchport
 switchport mode access
 switchport access vlan 10

int Gi1/2
 switchport
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport trunk allow vlan 10

int Vlan 10
 xconnect 1.1.1.2 10 encapsulation mpls

Remote Router

int Gi1/1
 switchport
 switchport mode access
 switchport access vlan 10

int Gi1/2
 switchport
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport trunk allow vlan 10

int Vlan 10
 xconnect 1.1.1.1 10 encapsulation mpls

Scalable EoMPLS
This new EoMPLS is configured under an EVC service instance using again the xconnect command. Label imposition/disposition is being done by the ingress module where the service instance is configured, so a module with EVC support (i.e. ES/ES+) is required.

You can use it for point-to-point L2 services between single attachment circuits, just like the PFC-based EoMPLS.

Besides that, when dealing with EVCs you can also configure the xconnect under a vlan (SVI) interface (when the service instance is mapped to a bridge-domain) for point-to-point L2 services between multiple attachment circuits, where you can also enable or disable local L2 connectivity using split-horizon.

Both EoMPLS configurations can be used concurrently on the same physical port, with less global resources (i.e. vlans) used in comparison to the first two EoMPLS types. Keep in mind that you still need a SIP or an ES/ES+ egress module for the SVI-based EoMPLS.

Local Router

int Gi1/1
 service instance 10 ethernet
  encapsulation dot1q 10
  xconnect 1.1.1.2 10 encapsulation mpls
 service instance 20 ethernet
  encapsulation dot1q 20
  rewrite ingress tag pop 1 symmetric
  bridge-domain 20

int Vlan 20
 xconnect 2.2.2.2 20 encapsulation mpls

Remote Router

int Gi1/1
 service instance 10 ethernet
  encapsulation dot1q 10
  xconnect 1.1.1.1 10 encapsulation mpls
 service instance 20 ethernet
  encapsulation dot1q 20
  rewrite ingress tag pop 1 symmetric
  bridge-domain 20

int Vlan 20
 xconnect 2.2.2.1 20 encapsulation mpls

Notes:
1) The vlan configured in "encapsulation vlan-id" under the service instance is local significant. The vlan configured in bridge-domain is a global vlan-id and can be different from the first one.

2) Scalable EoMPLS doesn't require global VLAN resources for the EoMPLS xconnect. In PFC-based EoMPLS each (sub)interface requires one global VLAN resource.

3) An attachment circuit (AC) is usually the customer connection to a service provider network (CE-PE). An AC may be a physical or virtual port/circuit and may be any transport technology, i.e. Frame Relay DLCI, ATM PVC, Ethernet VLAN.