Classify Traffic Based on MPLS

Multiprotocol Label Switching (MPLS) is a method of forwarding packets at a high rate of speed. PacketWise is able to classify traffic based on MPLS labels. Packeteer's implementation of MPLS support is based on RFC 3031 and 3032 (that is, the relevant subset that is applicable to Packeteer products; some of the sections in these RFCs apply to routers and switches only). For details related to this standard, go to ietf.org.

You can create an MPLS matching rule that is based on the top MPLS label that identifies the path through the core, and/or additional labels (2-5) in the MPLS stack that identify the organization or client for which the traffic is carried. You can also create classes based on the experimental bits (EXP) field in the MPLS label.

Classifying by the First MPLS Label

To set up a matching rule based on the first (top) MPLS label:

1. When creating a class or adding a matching rule, click MPLS. The Matching Rule: MPLS window opens.  show screen

2. In the MPLS First Label field, enter one of the following:

• To specify a single MPLS label, enter a number between 0 and 1048575.
• To specify a range of MPLS labels, enter the first and last numbers, separated by a dash (for example, 250-350)
• To match any traffic flow that has an MPLS label, type any.

3. Click OK.

4. Click add class or add rule.

Classifying by Other MPLS Labels

By default, PacketWise classifies traffic by the first MPLS label only, but you can also classify packets based on MPLS stacked labels 2 to 5. However, in order to do this, you need to specify which label position you want to classify. For example, to classify the second label in the stack, change the MPLS Additional Label system variable to 2.

To set up a matching rule based on other labels in the MPLS stack:

1. Set the MPLS Additional Label system variable to correspond to the stack position of the MPLS label you want to classify. See Adjust System Variables.

2. When creating a class or adding a matching rule, click MPLS. The Matching Rule: MPLS window opens.  show screen

3. In the MPLS Additional Label field, enter a number between 0 and 1048575.

4. Click OK.

5. Click add class or add rule.

Notes:

• Until you specify the stack position by adjusting the system variable, the MPLS Additional Label field will be ignored.
• You can create a single class that classifies both a top label and an additional label.
• You can create a parent class that classifies by top label and then create child classes that classify by additional labels, and vice versa.

Classifying by the MPLS Experimental Bits Field

The experimental bits field of the MPLS label on a packet can be used in different ways — for example, some routers use the EXP field to set class of service.

To set up a matching rule based on the MPLS experimental bits field:

1. When creating a class or adding a matching rule, click MPLS. The Matching Rule: MPLS window opens.  show screen

2. In the MPLS Experimental Field box, enter one of the following:

• To specify a single value, enter a number between 0–7.
• To specify a range of values, enter the first and last numbers, separated by a dash (for example, 1-3).
• To match any traffic flow that has a value in the experimental bits field, type any.

3. Click OK.

4. Click add class or add rule.

See also:

Create MPLS Policies

Enhance MPLS QoS