MPLS QoS Queues

This feature simplifies creating SD-WAN configurations when adding a Multiprotocol Layer Switching (MPLS) WAN Link. Previously, each MPLS queue required one WAN Link to be created. Each WAN Link required a unique Virtual IP Address (VIP) to create the WAN Link and a unique Differentiated Services Code Point (DSCP) tag corresponding to the provider’s queuing scheme. After defining a WAN Link for each MPLS queue, the Intranet Service to map to a specific queue is defined.

Currently, a new MPLS specific WAN Link definition (i.e., Access Type) is available. When a new Private MPLS Access Type is selected, you can define MPLS queues associated with the WAN Link. This allows a single VIP with multiple DSCP tags that correspond to the provider’s queuing implementation for the MPLS WAN Link. This maps the Intranet Service to multiple MPLS Queues on a single MPLS WAN Link.

Allows MPLS providers to identify traffic based on DSCP markings so that class of service can be applied by the provider.


If you have existing MPLS configurations and would like to implement the Private MPLS Access Type, please contact Citrix Support for assistance.

  1. Define the WAN Link Access Type as Private MPLS.
  2. Define the MPLS Queues corresponding to the Service Provider MPLS queues.
  3. Enable the WAN Link for virtual path service (enabled by default for Private MPLS WAN Links).
  4. From the virtual path on a WAN Link, assign an Autopath group.


If the Autopath Group is assigned from the WAN Link level, SD-WAN creates paths automatically between the MCN and Client MPLS Queues based on matching DSCP tags. If the Autopath Group is assigned from the MPLS Queue level, SD-WAN creates paths automatically regardless of whether or not the DSCP tags match.

  1. Ensure that the same Autopath Group is configured at the MCN and Client.

  2. Verify that the Paths for the WAN Link are built automatically.

  3. Assign Intranet Service to a specific queue, if needed.


The SD-WAN configuration may not have a one-to-one mapping for provider-based queues. This is based on specific deployment scenarios. You cannot create Autopath Groups between different Private Access Types. For instance, you cannot create Autopath Groups between a Private Internet Access Type and a Private MPLS Access Type.

To configure new WAN Link Access Type for Private MPLS:

  1. In the Configuration Editor, click + (Add) under Sites > [Site Name] > WAN Links, the Add WAN Link pop-up appears.

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  1. Under the Basic Settings, there is now a new MPLS Queues tab. Click + Add to add specific MPLS Queues. These should correspond with the queues defined by the Service Provider.

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Field Description
MPLS Queue Name The MPLS queue name
DSCP Tag Service Provider’s DSCP tag setting for the queue.
Unmatched When enabled, any frames arriving that do not match defined tags within the configuration file are mapped to this queue and the bandwidth defined for this queue.
LAN to WAN Permitted Rate (kbps) The amount of bandwidth that SD-WAN devices are permitted to use for upload, which cannot exceed the defined physical upload rate of the WAN Link.
WAN to WAN Permitted Rate (kbps) The amount of bandwidth that SD-WAN devices are permitted to use for download, which cannot exceed the defined physical download rate of the WAN Link.

Expand the MPLS Queue definition (by clicking the +), and additional options appear. These options include:

Field Description
Tracking IP Address WAN Link tracking address
Congestion Threshold The defined amount of time for congestion (in microseconds) after which the MPLS Queue will throttle packet transmission to avoid additional congestion. When congestion exceeds the set Threshold, SD-WAN backs off the sending rate.
Eligibility The MPLS Queue’s eligibility to process specific classes of traffic. When eligibility is disabled for a specific class of traffic, that class of traffic is unlikely to route through the MPLS Queue unless network conditions require it.

Configure the MPLS Queues that correspond to the existing Service Provider WAN Link queue definitions.


Any existing MPLS WAN Links that are configured prior to SD-WAN 9.1 are not impacted.

Once the Private MPLS WAN Link with its MPLS Queues is defined, you should assign an Autopath Group for the WAN Link under a specific Virtual Path definition.

To assign autopath group:

  1. Go to Connections > [Site Name] > WAN Links >[MPLS WAN Link Name] > Virtual Paths> [Virtual Path Name] > [Local Site] > WAN Links and click Edit ().

  2. Click the Autopath Group drop-down menu and choose from the available groups. By default, MPLS Queues inherit the Autopath Group assigned to the MPLS WAN Link. You may choose to set the individual MPLS Queues to Inherit the chosen Autopath Group or choose an alternate from the Autopath Group drop-down menu for each MPLS Queue.

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If there is no one-to-one mapping, based on DSCP tag, between queues at the local site and the remote site, you must map MPLS Queues to specific Autopath Groups. Inheriting an Autopath Group from the MPLS WAN Link will only automatically generate paths between queues with matching DSCP tags.

The Autopath Group defined is the same for the MCN and Client appliance. This allows the system to build the Paths automatically. At the MCN site you can also expand the WAN Link associated with the virtual path.

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The SD-WAN web interface now allows you to view the permitted rate for WAN Links and WAN Link Usages and whether a WAN Link, Path, or Virtual Path may be in a congested state. In the previous releases, this information was only available in SD-WAN log files and through the CLI. These options are now available in the web interface to assist in troubleshooting.

View Permitted Rate

Permitted Rate is the amount of bandwidth that a particular WAN Link, Virtual Path Service, Intranet Service, or Internet Service is permitted to use at a given point in time. The permitted rate for a WAN Link is static, and is defined explicitly in the SD-WAN configuration. The permitted rate for a Virtual Path Service, Intranet Service, or Internet Service will fluctuate over time, in response to congestion, user demand, and Fair Shares, but will always be greater than or equal to the Minimum Reserved Bandwidth for the Service.

Go to Monitor > Statistics, and select WAN Link from the Show drop-down menu.

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Monitor MPLS Queues

Go to Monitor > Statistics, and select MPLS Queues from the** Show **drop-down menu.

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