R2511-HP MSR Router Series ACL and QoS Configuration Guide(V5)

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Configuring FR fragmentation
The devices support end-to-end FRF.12 fragmentation.
On low-speed FR links, large data packets cause excessive delay. FR fragmentation can fragment large
FR packets into several small packets that 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, thus 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 of 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 (that is, a serial interface encapsulated with FR),
FRF.12 fragmentation does not work at the local end and packets are sent out of the local end
without being fragmented, however, FRF.12 fragmentation takes effect on the remote end.
Enabling FR fragmentation for an FR interface
To enable FR fragmentation function for an FR interface:
Step Command Remarks
1. Enter system view.
system-view
N/A
2. Enter FR interface view.
interface interface-type
interface-number
N/A
3. Enable FR fragmentation for
the FR interface.
fr fragment [ fragment-size ]
end-to-end
Disabled by default.
Enable FR fragmentation for FR PVCs
To configure FR fragmentation for FR PVCs:
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 ]
[ data-level | voice-level ]
Disabled by default.