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On low-speed FR links, large data packets cause excessive delay. FR fragmentation can fragment
large FR packets into several small packets which can be transmitted on low-speed links with low
delay.
When voice packets and data packets are transmitted simultaneously, large data packets occupy the
bandwidth for a long time. As a result, voice packets are delayed or even dropped, affecting voice
quality. The purpose of FR fragmentation configuration is to reduce delay for voice packets and
guarantee the real-time transmission of voice packets. With FR fragmentation configured, large data
packets are fragmented into small data fragments. Voice packets and the data fragments are sent
alternatively, so that voice packets can be timely and evenly processed and the delay for voice
packets is reduced.
Configuration restrictions and guidelines
•
The configured FR fragmentation function takes effect after you associate the FR PVCs
requiring FR fragmentation with the FR class and enable FRTS on the FR PVCs.
•
MFR interfaces do not support FRF.12 fragmentation. If the interfaces at both ends of a link are
MFR interfaces with FRF.12 fragmentation enabled, FRF.12 fragmentation does not take effect.
Packets are sent out from the local end without being fragmented and can be received by the
remote end. When pinging the remote end on the local end, you can get response from the
remote end. If the local MFR interface is connected to a normal FR interface (a serial interface
with FR encapsulation enabled), FRF.12 fragmentation does not work at the local end and
packets are sent out from the local end without being fragmented, however, FRF.12
fragmentation takes effect on the remote end.
Configuration procedure
To configure FR fragmentation:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter FR class view.
fr class
class-name
N/A
3.
Enable FR
fragmentation.
fragment
[
fragment-size
]
By default, FR fragmentation is
disabled.
Displaying and maintaining FR QoS
Task Command
Remarks
Display the mapping relationship
between FR classes and
interfaces (including the DLCIs of
an interface, subinterfaces of an
interface, and the DLCIs of
subinterfaces).
display
fr
class-map
{
fr-class
class-name
|
interface
interface-type interface-number
} [
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any
view.
Display the configuration and
statistics information about FR
QoS.
display fr pvc-info
[
interface
interface-type
interface-number
] [
dlci-number
] [
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any
view.
Display information about all the
configured FR switching PVCs.
display fr switch-table
{
all
|
name
switch-name
|
interface
interface-type interface-number
} [
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any
view.
