ATM PVC Bundle Enhancement MPLS EXP-Based PVC Selection

At the outset, this configuration defines a VC class called "bundle-class," which includes commands that set VC parameters. When the class bundle-class is applied at the bundle level, these parameters are applied to all VCs that belong to the bundle. Note that any commands applied directly to an individual VC of a bundle in bundle-vc mode take precedence over commands applied globally at the bundle level. Taking into account hierarchy precedence rules, VCs belonging to any bundle to which the class bundle-class is applied will be characterized by the following parameters: aal5snap encapsulation, broadcast on, use of Inverse ARP to resolve IP addresses, and OAM enabled.

router isis
 net 49.0000.0000.0000.1111.00
vc-class atm bundle-class
 encapsulation aal5snap
 broadcast
 protocol ip inarp
 oam-bundle manage 3
 oam 4 3 10

The following four sections of the configuration define specific VC classes. Each of these classes contains commands used to specify parameters that can then be applied to individual VCs in a bundle by assigning the class to that VC.

When the class called "control-class" is applied to a VC, the VC carries traffic whose MPLS EXP level is 7. When the VC to which this class is assigned goes down, it takes the bundle down with it because this class makes the VC a protected one. The QoS type of a VC using this class is vbr-nrt.

vc-class atm control-class
 mpls experimental 7
 protect vc
 vbr-nrt 1000 5000 32

When the class called "premium-class" is applied to a VC, the VC carries traffic whose MPLS EXP levels are 6 and 5. The VC does not allow other traffic to be bumped onto it. When the VC to which this class is applied goes down, its bumped traffic will be redirected to a VC whose MPLS EXP level is 7. This class makes a VC a member of the protected group of the bundle. When all members of a protected group go down, the bundle goes down. The QoS type of a VC using this class is vbr-nrt.

vc-class atm premium-class
 mpls experimental 6-5
 no bump traffic
 protect group
 bump explicitly 7
 vbr-nrt 20000 10000 32

When the class called "priority-class" is applied to a VC, the VC is configured to carry traffic with an MPLS EXP level in the 4 - 2 range. The VC uses the implicit bumping rule, it allows traffic to be bumped, and it belongs to the protected group of the bundle. The QoS type of a VC using this class is ubr+.

vc-class atm priority-class
 mpls experimental 4-2
 protect group
 ubr+ 10000 3000

When the class called "basic-class" is applied to a VC, the VC is configured through the mpls experimental other command to carry traffic with MPLS EXP levels not specified in the profile. The VC using this class belongs to the protected group of the bundle. The QoS type of a VC using this class is ubr.

vc-class atm basic-class
 mpls experimental other
 protect group
 ubr 10000
 

The following sets of commands configure three bundles that the router subinterface uses to connect to three of its neighbors. These bundles are called "new-york," "san-francisco," and "los-angeles." Bundle new-york has four VC members, bundle san-francisco has four VC members, and bundle los-angeles has three VC members.

The first part of this example specifies the IP address of the subinterface, the router protocol--the router uses IS-IS as an IP routing protocol--and it creates the first bundle called "new-york" and enters bundle configuration mode:

interface a1/0.1 multipoint
 ip address 10.0.0.1 255.255.255.0
 ip router isis
 bundle new-york

From within bundle configuration mode, the next portion of the configuration uses two protocol commands to enable IP and Open Systems Interconnect (OSI) traffic flows in the bundle. The OSI routing packets will use the highest MPLS EXP VC in the bundle. The OSI data packets, if any, will use the lowest MPLS EXP VC in the bundle. If configured, other protocols, such as Internet Packet Exchange (IPX) or AppleTalk, will always use the lowest MPLS EXP VC in the bundle.

As the indentation levels of the preceding and following commands suggest, subordinate to bundle new-york is a command that configures its protocol and a command that applies the class called "bundle-class" to it.

  protocol ip 1.1.1.2 broadcast
  protocol clns 49.0000.0000.2222.00 broadcast
  class-bundle bundle-class

The class called "bundle-class," which is applied to the bundle new-york, includes a protocol ip inarp command. According to inheritance rules, protocol ip, configured at the bundle level, takes precedence over protocol ip inarp specified in the class bundle-class.

The next set of commands beginning with pvc-bundle ny-control 207, which are further subordinate, add four VCs (called "ny-control," "ny-premium," "ny-priority," and "ny-basic") to the bundle new-york. A particular class--that is, one of the classes predefined in this configuration example--is applied to each VC to configure it with parameters specified by commands included in the class.

As is the case for this configuration, to configure individual VCs belonging to a bundle, the router must be in bundle mode for the mother bundle. For each VC belonging to the bundle, the subordinate mode is pvc-mode for the specific VC.

The following commands configure the individual VCs for the bundle new-york:

  pvc-bundle ny-control 207
   class-vc control-class
  pvc-bundle ny-premium 206
   class-vc premium-class
  pvc-bundle ny-priority 204
   class-vc priority-class
  pvc-bundle ny-basic 201
   class-vc basic-class

The following set of commands create and configure a bundle called "san-francisco." At the bundle configuration level, the configuration commands included in the class bundle-class are ascribed to the bundle san-francisco and to the individual VCs that belong to the bundle. Then, the pvc-bundle command is executed for each individual VC to add it to the bundle. After a VC is added and bundle-vc configuration mode is entered, a particular, preconfigured class is assigned to the VC. The configuration commands comprising that class are used to configure the VC. Rules of hierarchy apply at this point. Command parameters contained in the applied class are superseded by the same parameters applied at the bundle configuration level, which are superseded by the same parameters applied directly to a VC.

 bundle san-francisco
  protocol clns 49.0000.0000.0000.333.00 broadcast
  inarp 1
  class-bundle bundle-class
  pvc-bundle sf-control 307
   class-vc control-class
  pvc-bundle sf-premium 306
   class-vc premium-class
  pvc-bundle sf-priority 304
   class-vc priority-class
  pvc-bundle sf-basic 301
   class-vc basic-class

The following set of commands create and configure a bundle called "los-angeles." At the bundle configuration level, the configuration commands included in the class bundle-class are ascribed to the bundle los-angeles and to the individual VCs that belong to the bundle. Then, the pvc-bundle command is executed for each individual VC to add it to the bundle. After a VC is added and bundle-vc configuration mode is entered, the MPLS EXP level is set for the VC, and the VC is either configured as a member of a protected group (protect group) or as an individually protected VC. A particular class is then assigned to each VC to further characterize it. Rules of hierarchy apply. Parameters of commands applied directly and discretely to a VC take precedence over the same parameters applied within a class to the VC at the bundle-vc configuration level, which take precedence over the same parameters applied to the entire bundle at the bundle configuration level.

 bundle los-angeles
  protocol ip 1.1.1.4 broadcast
  protocol clns 49.0000.0000.4444.00 broadcast
  inarp 1
  class-bundle bundle-class
  pvc-bundle la-high 407
   mpls experimental 7-5
   protect vc
   class-vc premium-class
  pvc-bundle la-mid 404
   mpls experimental 4-2
   protect group
   class-vc priority-class
  pvc-bundle la-low 401
   mpls experimental other
   protect group
   class-vc basic-class