| Exam 642-887 | Question id=3192 | QOS in a Service Provider IP NGN Environment |
When implementing MPLS DS-TE on Cisco IOS XR routers, all aggregate Cisco MPLS TE traffic is mapped to which class type by default?
| A. |
class-type 0 (bandwidth global pool) | |
| B. |
class-type 1 (bandwidth subpool) | |
| C. |
class-type 2 (bandwidth priority) | |
| D. |
class type class-default (bandwidth best-effort) |
Differentiated Services Traffic Engineering
MPLS Differentiated Services (Diff-Serv) Aware Traffic Engineering (DS-TE) is an extension of the regular MPLS-TE feature. Regular traffic engineering does not provide bandwidth guarantees to different traffic classes. A single bandwidth constraint is used in regular TE that is shared by all traffic. To support various classes of service (CoS), users can configure multiple bandwidth constraints. These bandwidth constraints can be treated differently based on the requirement for the traffic class using that constraint.
MPLS diff-serv traffic engineering provides the ability to configure multiple bandwidth constraints on an MPLSenabled interface. Available bandwidths from all configured bandwidth constraints are advertised using IGP.
TE tunnel is configured with bandwidth value and class-type requirements. Path calculation and admission control take the bandwidth and class-type into consideration. RSVP is used to signal the TE tunnel with bandwidth and class-type requirements.
Diff-Serv TE can be deployed with either Russian Doll Model (RDM) or Maximum Allocation Model (MAM) for bandwidth calculations.