Figure 66 PHB Decision on Label Push

As it turns out, the case of label imposition is an easy one. The router doing the imposition always treats the packet according to the new outgoing PHB indicator. In Figure 6-6, this means that the packet is given PHB treatment for EXP 0.

The mpls2mpls and mpls2ip pop cases are not as straightforward. Figure 6-7 illustrates these cases.

Figure 6-7. PHB Decision on Label Pop

Figure 6-7. PHB Decision on Label Pop

In some cases, you will want the resulting packet to receive treatment according to the label that was removed, and in other cases, you will want the resulting packet to receive treatment according to the outermost indicator in whatever remains after the POP (MPLS EXP in the case of mpls2mpls and IP DSCP in the case of mpls2ip).

All these label operations can be confusing. The next section aims to unify them and make things easier to understand.

Was this article helpful?

0 0

Post a comment