Link Fragmentation And Interleaving - Cisco 10000 Series Configuration Manual

Fragmenting and Interleaving Real-Time and
Nonreal-Time Packets
Integrating delay-sensitive real-time traffic with nonreal-time data packets on low-speed links can cause
the real-time packets to experience long queuing delays while waiting for the larger nonreal-time packets
to transmit. Real-time traffic, however, cannot tolerate delay. The challenge becomes how to integrate
real-time and nonreal-time packets while reducing latency for the real-time packets. The Cisco 10000
series router addresses this by breaking larger data packets into fragments and interleaving the smaller
real-time packets between the fragments. In this way, time-sensitive real-time traffic remains intact and
does not experience excessive delay.
This chapter describes fragmentation and interleaving on the Cisco 10000 series router. It includes the
following topics:
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Link Fragmentation and Interleaving

Link fragmentation and interleaving (LFI) is a method that allows long nonreal-time data packets to be
fragmented into smaller frames and shorter real-time packets to be interleaved between the fragments.
In this way, real-time delay-sensitive packets, such as voice over IP (VoIP), and nonreal-time
delay-insensitive packets, such as data transfer, can be carried together on low-speed links without
causing excessive delay to the real-time traffic.
Real-time delay-sensitive traffic becomes susceptible to increased latency when the network processes
nonreal-time delay-insensitive packets. Long queuing delays can occur while real-time traffic waits for
the nonreal-time packet to be transmitted. Therefore, controlling the maximum one-way end-to-end
delay for time-sensitive traffic becomes challenging when integrating voice and data traffic.
OL-7433-09
Link Fragmentation and Interleaving, page 16-1
Multilink PPP-Based Link Fragmentation and Interleaving, page 16-11
FRF.12 Fragmentation, page 16-37
Configuration Examples for Link Fragmentation and Interleaving, page 16-59
Verifying and Monitoring Link Fragmentation and Interleaving, page 16-65
Related Documentation, page 16-69
C H A P T E R
Cisco 10000 Series Router Quality of Service Configuration Guide
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