Fragment - 3Com 3C13618 Command Reference Manual

3Com Router Command Reference Guide — V1.00

6.1.44 fragment

Syntax
fragment fragment-size { data-level | voice-level }
undo fragment [ fragment-size { data-level | voice-level } ]
View
Frame Relay class view
Parameter
fragment-size: Fragment size, in the range of 16 to 1600 bytes.
data-level: Configures the fragment if voice is not enabled.
voice-level: The fragment size if voice is enabled.
Description
Using the fragment command, you can configure fragment for Frame Relay. Using the
undo fragment command, you can disable the fragment setting.
By default, no Frame Relay compression is enabled.
When voice and data are transmitted concurrently, transmission of a large data packet
will occupy the bandwidth for a relatively long time. This will cause delay and even drop
of voice packets behind it, and hence degrade the voice quality. To ensure the voice
quality, the large data packet is fragmented into small packets. These smaller data
fragments and the voice packets are interspersed for transmission to ensure an even
flow of voice packets into the networks. However, there is the time that no voice is
waiting for transmission. Regardless of whether there is voice transmission demands,
however, fragmenting the large packets into the small packets of the same size will
waste the bandwidth resources. To efficiently use the bandwidth, the fragment size
should be dynamically adjusted. In the case of concurrent transmission of voice and
data but no voice is waiting for transmission, or in the case of transmission of only voice,
use the fragment size configured by the argument data-level. In the case that voice
and data are transmitted concurrently and there is voice waiting for transmission, use
the fragment size configured by the argument voice-level. However, if only data-level
fragment size is configured, it will be adopted in all cases, regardless of whether there
is voice. If only voice-level fragment size is configured, it will be adopted in the case that
there is voice. But fragmentation will not be implemented if there is no voice. In the
undo form of this command, if no parameter is input, fragmentation will not be
implemented, regardless of whether there is voice. If parameters have been input, it
should be the same parameter defined when making configuration, so that
non-fragmentation can be set for either statuses. For example, data-level and
voice-level fragment sizes have been respectively set to 160 and 100. The undo
fragment command will set non-fragmentation for both cases. The undo fragment
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