A red service frame is also out-of-bandwidth profile and is immediately
discarded.
The Color Mode (CM) parameter specifies whether the UNI is operating in a coloraware
or color-blind mode. When in a color-aware mode, the color associated with an
incoming service frame is employed; in the color-blind mode, the color indication is
ignored.
Bandwidth Profile Rate Enforcement The Bandwidth profile is enforced through
a two??“rate (committed or excess), three-color marker (green, yellow, or red) algorithm,
referred to as the trTCM algorithm; this algorithm is usually implemented using a
token bucket concept and is shown in Figure 2.7.
Two buckets, one referred to as the ???committed??? or C-bucket and the other referred
to as the ???excess??? or E-bucket, are used. Initially, each of these buckets is full of tokens;
the C-bucket has green tokens and the E-bucket has yellow tokens. As service frames
enter the Service Provider network UNI, the same number of tokens in the C-bucket
are removed (decreased). If, after this, there are green tokens in the C-bucket, then the
service frame is CIR-conformant, colored green, and allowed in the network.
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