You can differentiate traffic within a private WAN link by defining multiple Classes of Service (CoS). The following example is a simple scenario in which a percentage of the bandwidth (10Mbps) is assigned to three Classes of Services.
Edge WAN Settings for MPLS Private Links Example
In this simple example, the user has 10Mbps bandwidth available. They want to send some traffic to voice, some traffic to PCI data, and all other data to be designated as default traffic. The types of traffic (CoS) will be defined by the user via Differentiated Services Code Point (DSCP) Tag(s), as shown in the table below.
Table: MPLS CoS Example
| Class of Service | Description | DSCP Tags | Policing | Static SLA | |||
| Bandwidth (Percentage) | Latency | Jitter | Loss | ||||
| CoS1 | Voice | CS5, EF | |
60 | 10ms | 4ms | 0.005% |
| CoS2 | Video | AF41, CS4 | 20 | 15ms | 4ms | 0.05% | |
| CoS3 | File Transfer | AF21, CS2 | 20 | 15ms | 4ms | 0.1% | |
| Link Characteristics | 15ms | 4ms | 0.1% | ||||
Therefore, according to the above table, the voice on a MPLS CoS would be identified as DSCP tag CS5, EF, Video on a MPLS CoS would be identified as AF41, CS4, and the file transfer on a MPLS CoS would be identified as DSCP tag AF21, CS2. See the Private Link Configuration image below for an example.
Policing MPLS CoS
For a private link that has CoS agreement with a MPLS provider, a Service Provider will guarantee a different SLA for each CoS on a MPLS Link. The DMPO can treat each CoS as a different link and can take granular application aware decisions for a private link with CoS agreements. A Policer can be defined for a MPLS CoS underlay to ensure that the Service Provider committed bandwidth SLAs are being honored by the customer.
