Re: [j-nsp] Questions on QoS commands

From: Sean Capshaw (capshaw@juniper.net)
Date: Thu Mar 14 2002 - 07:59:48 EST


Arun,

Here is a description of classification functionality within CoS. Hope
it helps. I just describe IPV4 - haven't included mpls - hope thats ok:

All M-series routers provide four outbound transmission queues for each
physical link and up to 64 per FPC. You can assign IPV4 traffic to
different queues for different service levels. You can assign traffic to a
FC and then assign the FC to a specific outbound transmission queue. The
aggregation of different traffic types into a single FC to receive the
same forwarding precedence is referred to as a BA. There are three basic
mechanisms for assigning traffic to a FC.

1. Default Classifier - By default all IPV4 traffic with the
exception of IP routing protocol control traffic will be assigned to queue
0, IP routing protocol control traffic will be assigned to queue 3. IP
routing protocol control traffic is identified by the fact that the first
three bits if it's DSCP are set to '110 or 111'. An example of this is to
enter the following configuration under the <edit class-of-service>
hierarchy:

        classifiers {
            dscp dscp-classifier {
                import default;
                }
        }

        forwarding-classes {
           queue 0 FC-name;
            queue 3 FC-name;
        }

2. Multi Field Classifier - You can also assign traffic to a FC
through firewall filter configuration, in which case you can select the FC
based on any of the criteria on which you can match a packet in a firewall
filter. An example of this would be to enter the following
configuration. First under the <edit firewall-filter> hierarchy:

        filter filter-name {
            term a {
                from {
                    source-portport-number;
                        }
                then forwarding-class FC -name;
            }

        NOTE: Don't forget to apply the filter to the appropriate
interfaces

        Then under the <edit class-of-service> hierarchy:

        classifiers {
            dscp dscp-classifier {
                import default;
                forwarding-class FC-name {
                    loss-priority high code-points 001000;
                   }
              }
        }
        forwarding-classes {
            queue 0 FC-name;
            queue 1 FC-name;
          queue 2 FC-name;
         queue 3 FC-name;
        }

3. Classification Override - You can override the configured or
default settings and assign IPV4 traffic to a FC based on the destination
prefix. An example of this is to define a policy class at the <edit
class-of-service policy>

forwarding-policy {
        class class-name {
                classification-override {
                        forwarding-class class-name {
                                }
                        }
                }
        }
and under the <edit policy options policy-name> hierarchy associate a
destination prefix with the class:

                policy-statement policy-name {
            term term-name {
                from {
                    route-filter destination-prefix match-type <class
class-name >;
                }
                then class class-name ;
            }
                }

Thanks
Sean

On Thu, 14 Mar 2002, Arun wrote:

> Hi,
>
> I have few questions on DiffServ Based QoS configuration on Juniper
> routers,
>
> In Juniper's "Class of Service" document i could not find commands
> to classify the IP traffics, there are commands to give actions(like,
> RED, rate limiting, policer etc...).
> Whereas Cisco QOS CLI provides commands for IP traffic
> classification (conditions, like src/dest IP address, port number,
> TOS/DSCP values) and actions (RED, rate limiting, policer,
> bandwitdth etc...)on an interface.
>
> The Juniper's "Policy Framework" document provides commands for conditions
> (classifying) and actions for firewall filter(IPSec) configuration.
> I think it does not classifying IP traffic for non-IPSec configurations(to
> configure
> bandwitdth, priority , policing etc in interface mode as done by Cisco QoS
> CLI ).
>
> In Cisco QoS CLI it is possible to configure conditions(classification) and
> actions for
> a router using the class-map and policy-map commands and this policies
> can be serviced for a particular interface within a Cisco router.
>
> Is similar thing possible in Juniper router? An example would help.
>
> Please let me know.
>
> Regards,
> Arun
>
>
>



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