Rx Session Additional AVPs

Rx Sessions can include the following AVPs.

Flow-Description

The Flow-Description AVP appears in the Rx AAR to identify an IP data flow to or from a device and in a Gx CCA/RAR when installing PCC rules governing that flow. It has a string encoded in the IPFilterRule format from the Diameter base protocol (RFC3588/6733) describing traffic from the device to the network or from the network to the device. Traffic flows out from APN to the device and in from the device to the APN. For example, if UserA from device IP 10.1.2.3 port 111 is calling UserB at IP 192.168.9.10 port 222:
  • UserB using APN out to UserA: permit out 17 from 192.168.9.10 222 to 10.1.2.3 111
  • UserA into APN en route to UserB: permit in 17 from 10.1.2.3 111 to 192.168.9.10 222

This string is not parsed by MATRIXX Engine. It is treated as an opaque BLOB that is stored in the database and copied from Rx to Gx.

Flow-Status

Each flow must indicate a Flow-Status. This can be per component or per sub-component or flow. Available values are:
  • ENABLED-UPLINK (0)
  • ENABLED-DOWNLINK (1)
  • ENABLED (2)
  • DISABLED (3)
  • REMOVED (4)
Often, the media RTP Flow-Status is on the component while signaling Flow-Status is on the sub-component. Media RTCP sub-components are always ENABLED (2) until their component is removed. REMOVED removes the component or sub-component from the Rx session. Gx policy is not computed for DISABLED or REMOVED flows. Flows can change status over the course of a session. In general:
  • Signaling always stays ENABLED.
  • Signaling and audio are not REMOVED.
  • Audio components often start as UPLINK before transitioning to ENABLED.
  • Video components often change between ENABLED and REMOVED.

You can normalize on component and sub-component Flow-Status to differentiate them.

Rx QoS AVPs

Quality of Service (QoS) AVPs can include the following:
  • Media-Component-Description
    • Max-Requested-Bandwidth-DL
    • Max-Requested-Bandwidth-UL
    • Max-Supported-Bandwidth-DL
    • Max-Supported-Bandwidth-UL
    • Min-Desired-Bandwidth-DL
    • Min-Desired-Bandwidth-UL
    • Min-Requested-Bandwidth-DL
    • Min-Requested-Bandwidth-UL
    • RR-Bandwidth
    • RS-Bandwidth
  • Media-Sub-Component
    • Max-Requested-Bandwidth-DL
    • Max-Requested-Bandwidth-UL
Note: Usually, only these AVPs are supplied, and only on the component:
  • Max-Requested-Bandwidth-DL/DL
  • RR/RS-Bandwidth

Service-URN

The Service-URN AVP is used to identify emergency calls (such as US 911/UK 999). It is automatically copied into the MtxApplicationSessionExtension ServiceUrn field for use by normalizers. Example values include sos, sos.fire, sos.police, and sos.ambulance. If present, it can be used to give higher QoS to these calls.