This variation is very similar to the Uniform mode, with the difference being that the ingress PE will automatically remark any traffic that falls outside of the predefined QoS policy the provider has in place. The customer is given a chart that details how the provider will handle different DSCP markings from the customer. The customer traffic, upon reception, will be either remarked or automatically placed into the appropriate class of forwarding if their DSCP markings fell in range of the providers QoS policy.
This is the most common QoS policy framework I have dealt with. The objective of our demo here is to take Telnet traffic and remark it to EXP3 on ingress to the MPLS backbone and deliver it to the remote end without modifying the DSCP markings of the IP traffic exiting the egress PE to the customer. We can do a number of other things, like set a Bandwidth priority or LLQ value, but we'll simply deliver the traffic back to the customer with CS6, which is the marking the traffic was received with.
CSR1
class-map match-any CM_IP_PRECEDENCE6
match ip precedence 6
!
policy-map PM_QOS_IN_FROM_CUSTOMER
class CM_IP_PRECEDENCE6
set mpls experimental imposition 3
CSR5
class-map match-all CM_EXP3
match mpls experimental topmost 3
!
class-map match-all CM_QOS_GROUP3
match qos-group 3
!
policy-map PM_QOS_TO_CUSTOMER
class CM_QOS_GROUP3
!
policy-map PM_QOS_FROM_CORE
class CM_EXP3
set qos-group 3
IOS17#telnet 10.101.18.18 /source-interface loopback 101
Trying 10.101.18.18 ... Open
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User Access Verification
Username: Rob
Password:
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
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* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************
IOS18#
This is the most common QoS policy framework I have dealt with. The objective of our demo here is to take Telnet traffic and remark it to EXP3 on ingress to the MPLS backbone and deliver it to the remote end without modifying the DSCP markings of the IP traffic exiting the egress PE to the customer. We can do a number of other things, like set a Bandwidth priority or LLQ value, but we'll simply deliver the traffic back to the customer with CS6, which is the marking the traffic was received with.
CSR1
class-map match-any CM_IP_PRECEDENCE6
match ip precedence 6
!
policy-map PM_QOS_IN_FROM_CUSTOMER
class CM_IP_PRECEDENCE6
set mpls experimental imposition 3
CSR5
class-map match-all CM_EXP3
match mpls experimental topmost 3
!
class-map match-all CM_QOS_GROUP3
match qos-group 3
!
policy-map PM_QOS_TO_CUSTOMER
class CM_QOS_GROUP3
!
policy-map PM_QOS_FROM_CORE
class CM_EXP3
set qos-group 3
IOS17#telnet 10.101.18.18 /source-interface loopback 101
Trying 10.101.18.18 ... Open
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************
User Access Verification
Username: Rob
Password:
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************
IOS18#
We can see traffic coming from the customer marked with CS6.
We can see that the MPLS EXP bit is set to 3 which is what the QoS policy was configured to do, set the label EXP to 3 on imposition or the push operation. Both labels received the treatment.
With the traffic leaving the SP network we can see that the CS6 marking is still in place. We don't keep the SP markings applied to the customer traffic, we remark it to meet our needs and the remove the markings on egress.
