2.3.3. P-Charging-Vector

This page preserves the RFC text for the section and adds navigation metadata for the documentation site.

RFC Text

2.3.3. P-Charging-Vector

[RFC7315] defines an Inter Operator Identifier (IOI) to enable different operators involved in a SIP dialog or a transaction outside a dialog to identify each other by exchanging operator identification information within the P-Charging-Vector header field.

In the interconnection scenarios in multi-operator environments, where one or more transit operators are between the originating and terminating operator, the identities of the involved transit operators are represented by a transit-ioi parameter of the P-Charging-Vector header field.

Transit operators can be selected independently for each SIP method and direction of request. A transit network will only have knowledge of an individual SIP request, and transit network selection will be an independent decision for each request and could be made based on load, cost, percentage, time of day, and other factors. For this reason, it is necessary that the P-Charging-Vector header field, which carries the transit IOI information, is included in each SIP request and response. However, [RFC7315] does not allow the usage of the P-Charging-Vector header field in the SIP ACK request.

A SIP proxy that supports this extension and receives the SIP ACK request may include a P-Charging-Vector header field in the SIP ACK request.

The P-Charging-Vector header field shall not be included in SIP ACK requests triggered by non-2xx responses.