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MPLS for EX Series Switches Overview


You can configure Junos OS MPLS on Juniper Networks EX Series Ethernet Switches to increase transport efficiency in the network. MPLS services can be used to connect various sites to a backbone network and to ensure better performance for low-latency applications such as voice over IP (VoIP) and other business-critical functions.


MPLS configurations on EX Series switches are compatible with configurations on other Juniper Networks devices that support MPLS and MPLS-based circuit cross-connect (CCC). MPLS features available on the switches depend upon which switch you are using. For information about the software features on the EX Series switches, see Feature Explorer.


MPLS configurations on the switches do not support:

  • Q-in-Q tunneling

This topic describes:

Benefits of MPLS

MPLS has the following advantages over conventional packet forwarding:

  • Packets arriving on different ports can be assigned different labels.

  • A packet arriving at a particular provider edge (PE) switch can be assigned a label that is different from that of the same packet entering the network at a different PE switch. As a result, forwarding decisions that depend on the ingress PE switch can be easily made.

  • Sometimes it is desirable to force a packet to follow a particular route that is explicitly chosen at or before the time the packet enters the network, rather than letting it follow the route chosen by the normal dynamic routing algorithm as the packet travels through the network. In MPLS, a label can be used to represent the route so that the packet need not carry the identity of the explicit route.

Additional Benefits of MPLS and Traffic Engineering

MPLS is the packet-forwarding component of the Junos OS traffic engineering architecture. Traffic engineering provides the capabilities to do the following:

  • Route primary paths around known bottlenecks or points of congestion in the network.

  • Provide precise control over how traffic is rerouted when the primary path is faced with single or multiple failures.

  • Provide efficient use of available aggregate bandwidth and long-haul fiber by ensuring that certain subsets of the network are not overutilized while other subsets of the network along potential alternate paths are underutilized.

  • Maximize operational efficiency.

  • Enhance the traffic-oriented performance characteristics of the network by minimizing packet loss, minimizing prolonged periods of congestion, and maximizing throughput.

  • Enhance statistically bound performance characteristics of the network (such as loss ratio, delay variation, and transfer delay) required to support a multiservice Internet.

Related Documentation