Virtual Circuit Overview and Technical Specifications

A virtual circuit (VC) is a logical connection between two endpoints. You can provision a virtual circuit and begin passing traffic within minutes, adjust the capacity to fit your needs, and update VLAN tags as necessary.

PacketFabric virtual circuits typically Ethernet Virtual Private Lines (EVPL). We offer the following EVPL services:

  • Backbone virtual circuits - Connection between your equipment in two different locations
  • Marketplace virtual circuits - Use the marketplace to connect to a provider in the PacketFabric marketplace.
  • Internet Exchange (IX) virtual circuits - Connect to an Internet Exchange provider.
  • Hosted and dedicated cloud connections - Connect to a cloud service provider (CSP) such as AWS, Google, or Azure.

For information about marketplace and IX circuits, see Marketplace and IX Connections Overview.

For information about connecting to cloud service providers, see Cloud Connectivity.

Multi-point connections

Virtual circuits are multi-point to multi-point connections. This means that you can have multiple virtual circuits provisioned on a single access port.

Virtual circuits connecting

Note: How you manage virtual circuit capacity is entirely up to you. We do not restrict your ability to oversubscribe a port (for example, provisioning three 10 Gbps virtual circuits on a 10 Gbps port).

EPL connections

The exception to the multi-point model above is an Ethernet Private Line (EPL) virtual circuit. When you create a backbone virtual circuit, you have the option to make it an EPL connection.

EPL connections occupy the full port. This is why point-to-point connections (which are also EPL) bundle the EPL circuit with two ports.

However, EPL connections also provide more functionality and support. For more information about the differences between EPL and EVPL, see Virtual Circuit Ethernet Features and Ethernet Service Specifications.

Billing and terms

See Virtual Circuit Terms and Billing.

For a price list, see our pricing page.

Technical notes and constraints (EVPL)

  • Header row

    • Feature
    • Description
  • Row 1

    • Vendor restrictions
    • None. Virtual circuits are vendor-agnostic.
  • Row 2

    • Virtual circuits per port
    • Up to 4,000.
  • Row 2

    • Burst size
    • 6250000 bytes
  • Row 2

    • Supported protocols
      • BFD
      • GARP/GMRP
      • Jumbo frames (up to 9000)
      • LACP (not tunneled)
      • MPLS unicast
      • MacSec (only supported when the VLAN ID is not encrypted)
      • MPLS multicast
      • Multicast
      • Spanning trees
      • Q-in-Q
  • Row 2

    • Unsupported protocols
      • ELMI
      • Link OAM
      • LLDP
      • Pause frames
      • PNAC 802.1X
      • Provider bridge group access

Ethernet specifications

  • Header
    • Service
    • Service Features
  • Row
    • Ethernet Virtual Private Line (EVPL)
    • Ethernet and IP header support:
      Tag protocol IDs: 0x88a8, 0x8100, 0x9100
  • Row
    • Untagged VLAN support:
      • Not supported on Edge Fabric Router (EFR) devices.
      • Partially supported on Core Fabric Router (CFR) devices: one side can be untagged, but not both.
  • Row
    • Tagged VLAN support:
      VLANs 4-4094 are available for handoff at each port
  • Row
    • Quality of Service marking:
      • Support preservation of IP precedence/DSCP bits: Yes
  • Row
    • MAC addresses per endpoint:
  • Row
    • Broadcast, Unknown Unicast, Multicast (BUM) traffic support:
      All BUM traffic is transported end-to-end.
  • Row
    • Core/Backbone service resilience:
      EVPL service is protected with Node+Link Fast Reroute technology, ensuring sub-50ms service restoration.