CCIE RS – Describe WAN Rate-based Ethernet Circuits – Metro and WAN Ethernet Topologies


  • Enables carriers to bring various WAN connections (IP or MPLS) together in a single logical ethernet network
  • Allows MPLS networks to provide multipoint ethernet services
  • Allow CE nodes to communicate directly with other CE nodes
  • Ethernet Bridges – Pseudo-Wires (PW)
  • Forwards frames at L2
  • Self-learn source MAC address to port and frames are forwarded based on destination MAC address
    • If MAC is unknown, broadcast or multicast is flooded out all ports associated with virtual bridge
  • Architecture must perform
    • Auto discover other PE’s associated with the VPLS instance
    • Signaling of PWs to interconnect VPLS virtual Switch Instance (VSI)
    • Loop avoidance
    • MAC address withdrawal


  • • Separated into different subsections
    • Port-based
    • Per-vlan
    • Per-class per-vlan



Ethernet private line (EPL) (for example, Ethernet mapped to SONET/SDH frames) or Ethernet Internet access with IPsec encryption (no split tunnel)


Ethernet Virtual Private Line (EVPL), also called Ethernet Relay Service (ERS)




Ethernet Internet access with multipoint DMVPN or MPLS Ethernet access to group encrypted transport (GET)


Ethernet Relay Multipoint Service (ERMS) or Ethernet Multipoint Service (EMS)



Carrier Ethernet Services

  • Ethernet Virtual Private Line – E-LINE

    • Connect 2 customer ethernet ports over a WAN
    • Ethernet Private Line (EPL)
      • Provide p2p ethernet virtual connection (EVC) between a pair of user network interfaces (UNIs)
      • High degree of transparency
    • ○ Ethernet Virtual Private Line (EVPL)
      • Provide p2p or p2m between a pair of UNIs
  • Ethernet Virtual Private LAN – E-LAN

    • Multipoint service connecting sets of customer endpoints
    • Appearance of a bridged ethernet connecting the sites
  • Ethernet Virtual Private Tree – E-TREE

    • Multipoint service connecting one or more root to a set of leaves

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