Chapter 5 Quality of Service and Bandwidth Management

H.248 Traffic Management Package Support

for either a media flow or signaling flow. Once tman/pol is specified as ON and both the tman/sdr and tman/mbs properties are present, the DBE polices traffic based on the values of the tman/sdr and tman/mbs parameters.

The supported tman properties have the following functions:

The tman/sdr property defines the sustainable data rate in bytes per second that is permitted for the stream. It has a numerical value.

The tman/mbs property defines maximum burst size in bytes for the stream. It has a numerical value.

The tman/pol (policing) property can be set to ON or OFF or Absent.

When the tman/pol property is set to ON, policing is applied at the point of entry for traffic entering the media gateway (MG).

When both the tman/sdr and tman/mbs properties are present (and the tm/pol property is ON), the DBE polices traffic based on the sdr and mbs Tman parameters.

However, the absence of both tman/sdr and tman/mbs properties is permissible. In this case, the DBE polices traffic based on the Session Description Protocol (SDP).

Note If either the tman/sdr or tman/mbs property is present, then the other property must be present; that is, both the tman/sdr and tman/mbs properties must be present. In this case, the DBE polices traffic based on the sdr and mbs parameters.

When the tman/pol property is set to OFF, no policing is applied to traffic entering the media gateway.

If the tman/pol property is Absent, policing is done based on the SDP for the stream for a media flow. No policing is done for a signaling flow.

Note Absent means that the property has not been defined. If no tman properties (tman/pol, tman/sdr, and tman/mbs) have been defined, then the behavior for a media flow is to calculate the required bandwidth from the Session Description Protocol (SDP) in the local descriptor. For a signaling flow, the behavior is to perform no policing.

The tman properties (tman/pol, tman/sdr, and tman/mbs) are defined using Add and Modify requests, and they are returned on subsequent responses to Audit requests.

The tman properties have the following caveat:

The DBE issues error 421 indicating “Unknown action or illegal combination of actions” for any programming containing other fields and programming that sets the tman/pol flag, but only specifies one of the tman/sdr or tman/mbs values.

Table 5-1describes the asymmetric flow policing behavior of the two sides of a gate based on whether the tman/pol property is specified as ON, OFF, or Absent. Each side of the gate behaves independently of the other side. The Access Side might be the subscriber side to the DBE, and the backbone side might be the network core to the DBE.

Cisco IOS XE Integrated Session Border Controller Configuration Guide for the Cisco ASR 1000 Series Aggregation Services Routers

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