MPLS QoS
Table 1
Tunneling
Mode
Uniform
Pipe
Short Pipe
MPLS Uniform Mode
In uniform mode (shown in
when traversing the MPLS network. If the DiffServ marking of the packet is modified within the MPLS
network, the updates information is the one considered meaningful at the egress of the LSP. Any changes
to the packet marking within the MPLS network are permanent and get propagated when the packet
leaves the MPLS network.
Figure 3
MPLS Pipe Mode
In pipe mode (shown in
network. First, the marking used by intermediate nodes along the LSP span including the egress LSR.
Second, the original marking carried by the packet before entering the MPLS network that will continue
to be used once the packet leaves the MPLS network. Any changes to the packet marking within the
MPLS network are not permanent and do not get propagated when the packet leaves the MPLS network.
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide
QC-176
Overview of MPLS Tunneling Modes
IP-to-Label
Copy IP precedence
/DiffServ to MPLS EXP
MPLS EXP set according to
service provider policy
MPLS EXP set according to
service provider policy
Figure
Uniform Mode
EXP = 5
EXP = 5
DSCP = 5
DSCP = 5
Ingress
PE
Figure
4), two markings are relevant for a packet when traversing the MPLS
Modular QoS Deployment Scenarios on Cisco ASR 9000 Series Routers
Label-to-Label
MPLS EXP copied
MPLS EXP copied
MPLS EXP copied
3), there is only one DiffServ marking that is relevant for a packet
EXP = 5
EXP = 5
DSCP = 5
LSP
P
P
Label-to-IP
Copy MPLS EXP to IP
precedence/DiffServ
Preserve IP precedence
/DiffServ
Forwarding treatment based
on MPLS EXP
Preserve IP precedence
/DiffServ
Forwarding treatment based
on IP precedence/DiffServ
EXP = 5
DSCP = 5
DSCP = 5
Egress
PE
OL-23108-02