DS-TE Application
Scenario 1: Different Services of a VPN Transmitted over an MPLS TE Tunnel
An MPLS TE tunnel may need to transmit expedited forwarding (EF), assured forwarding (AF), and best-effort (BE) services of the same VPN. These services have different QoS requirements.
Multiple VPNs and TE tunnels can be created to prevent interference among different services. However, a large number of TE tunnels are required if multiple VPNs transmit different services concurrently on the network, which is a waste of resources.
Another solution is to deploy DiffServ-aware Traffic Engineering (DS-TE). DS-TE uses an LSP with multiple class types (CTs) to transmit different services of a VPN. A multi-CT LSP supports a maximum of eight CTs, each of which maps a service on a VPN and isolates services from each other.
Scenario 2: Services of Different VPNs Transmitted over an MPLS TE Tunnel
An MPLS TE tunnel may need to transmit services of different VPNs. With different QoS requirements, these VPNs compete for resources, which cannot guarantee QoS.
Different solutions are provided to guarantee QoS, depending on the VPN service type:
Each VPN has its own totally different service types.
If the number of service types is smaller than or equal to 8, set up a TE tunnel to transmit these services.
For example, VPN1 and VPN2 connect to an MPLS network. VPN1 provides EF and BE services, while VPN2 provides only the AF service. You need to set up only one TE tunnel and configure a different CT for each service on the VPNs. In this example, you need to configure three CTs because there are a total of three service types on the two VPNs.
All VPNs have identical service types.
Set up a TE tunnel for each VPN and configure CTs on each TE tunnel according to the service type quantity corresponding to VPNs.
For example, VPN1 and VPN2 connect to an MPLS network. Both VPN1 and VPN2 provide EF and BE services. You need to set up two TE tunnels to transmit services of the two VPNs separately. Configure a CT for each service type on each tunnel.
Multiple VPNs have identical service types.
Set up a TE tunnel for each VPN and configure CTs on each TE tunnel with the same quantity as the VPN service type.
Scenario 3: VPN Traffic and Non-VPN Traffic Concurrently Transmitted over an MPLS TE Tunnel
VPN traffic and non-VPN traffic coexist on a VPN and have different QoS requirements. If transmitted over a TE tunnel, VPN traffic and non-VPN traffic may compete for resources, which cannot guarantee QoS.
VPN traffic and non-VPN traffic have totally different service types.
Set up one TE tunnel to transmit both VPN traffic and non-VPN traffic. Configure different CTs for the different service types of VPN traffic and non-VPN traffic. The quantity of CTs equals the total number of VPN traffic and non-VPN traffic service types.
VPN traffic and non-VPN traffic have identical service types.
Set up two TE tunnels, respectively, for VPN traffic and non-VPN traffic and configure different CTs on each TE tunnel.
VPN traffic and non-VPN traffic have some identical service types.
Set up two TE tunnels, respectively, for VPN traffic and non-VPN traffic and configure different CTs on each TE tunnel.