> - Downloads
> - Congestion Point Expressions
> - Related Topics
> - Overview of Congestion Point Classification
> - Classifying Congestion Points
> - Defining a Congestion Point Profile
> - Configuration Statements for Congestion Point Classification

> ## Congestion Point Expressions

> You can enter a congestion point expression by using the syntax listed in this topic. You can also embed Python scripting expressions within the congestion point expression.

> If you embed Python expressions within a congestion point expression, use the escape sequence <- then -> to enclose the Python expression. See Methods for Use with Scripting Expressions and Match Criteria for Congestion Point Classification .

> The syntax for a congestion point expression is:

> <NetworkDevice>/<NetworkInterface>[/<CongestionPoint>]

> - <NetworkDevice>—Network device listed in the directory.
> - <NetworkInterface>—Network interface listed in the directory.

>   For information about interfaces, see Overview of Classification Scripts .

> - <CongestionPoint>—(Optional) Name of an instance of a congestion point that is automatically created.

> If one of the elements with the path contains a slash (/), use a backslash (\) as an escape character for the slash. For example, \/.

> ## Expressions in Templates for Congestion Point Profiles

> You can create a congestion point profile to be used as a template for other profiles. Templates simplify management of congestion points. Rather than configuring each congestion point individually, you can create templates to define common parameters for a class of individual congestion points.

> For example, in an environment in which VLAN interfaces GigabitEthernet1/0.1 through GigabitEthernet1/0.1000 have the same available bandwidth, you can specify the characteristics of the VLAN interface once and have SRC ACP create the congestion points based on the template configuration.

> When a congestion point expression has the third element (<CongestionPoint>), SRC ACP uses the <NetworkDevice>/<NetworkInterface> part of the expression to load the congestion point from the directory, and uses it as a template to create a congestion point in memory for subscriber. The <CongestionPoint> part of the expression distinguishes each congestion point (available bandwidth) created from this template.

> ## Methods for Use with Scripting Expressions

> SRC ACP provides the following methods to use in scripting expressions:

> - slot(nasPortId)—Collects the slot number from the nasPortId or interfaceName

>   Example—slot(“ atm 4/5:0.32” ) == “ 4”

> - port(nasPortId)—Collects the port number from the nasPortId or interfaceName

>   Example—port(“ atm 4/5:0.32” ) == “ 5”

> - l2id(nasPortId)—Collects the layer 2 ID from the nasPortId (VLAN id or ATM vpi.vci)

>   Example—l2id(“ atm 4/5:0.32” ) == “ 0.32”

> - escape(string)—Replaces any slash with the escape sequence \/

>   Example—escape("atm 4/5") == "atm 4\/5"

> ## Match Criteria for Congestion Point Classification

> You can use the match criteria in Python scripting expressions for a congestion point expression. For more information about the match criteria, see Congestion Point Classification Criteria.

> #### Published: 2009-09-15

> Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice.