• Supported Platforms
• MX Series

• Related Topics
• Configuring PTSP
• Configuring Static PTSP Rules

Packet-Triggered Subscribers Services Overview

The packet-triggered subscribers and policy control (PTSP) feature allows the application of policies to dynamic subscribers that are controlled by a subscriber termination device. You can associate specific subscriber contexts based on IPv4 addresses and provide dynamic service activation and deactivation for these subscribers. Once the subscribers are present in the subscriber database on the router, PSTP can report the subscribers to the SAE using the PTSP application so that the SRC software can manage the subscribers and services.

PTSP policies can be downloaded dynamically from the external policy manager (such as SRC) or configured statically on the router. The PTSP policies can be configured for each distinct IPv4 source address for a given interface on which the service is configured. Each distinct IPv4 address is considered a subscriber and all PTSP policies are applied on a per-subscriber basis. Dynamic policies, which are always specific to a subscriber, take precedence over static policies.

You can set up PTSP policies to:

• Manage traffic by configuring filtering, rate-limiting, and QoS enforcement in the rules.
• Steer traffic by specifying the forwarding instance in the forward rule.
• Collect accounting information by service rule or by application.

When you configure PTSP policies, you must specify the type of statistics collection (count) and the IP address used to identify the packet-triggered subscriber (demux) in the service rule. All service rules attached to a given service set must have the same settings for these options.

For the statistics collection type, terms and rules also cannot mix and match the following styles:

• rule—Statistics are aggregated in one bucket for the service rule and Diameter is used to report the statistics.
• application—Statistics are aggregated by application for a specific application, for a specific application group, or in one bucket. The statistics are reported in a flat file.

Subscriber instantiation is triggered for ingress packets by the IP address. When source address is specified, the source IP address of the ingress packets is used to establish the subscriber context. When destination address is specified, the destination IP address of the ingress packets is used to establish the subscriber context. If the IP address does not correspond to a known subscriber, then a new subscriber context is created to log in the packet-triggered subscriber.

The match conditions include local address, local port, remote address, and remote port. The following table describes how the demux value changes the IP address or port used for these terms.