Transmit Processing; Receive Processing - Cisco 10000 Series Configuration Manual

Quality of service configuration guide

Hide thumbs Also See for 10000 Series:

Table of Contents

Fragmenting and Interleaving Real-Time and Nonreal-Time Packets

Transmit Processing

The purpose of MLP over ATM-based LFI transmit processing is to fragment large nonreal-time

delay-insensitive packets and interleave smaller real-time delay-sensitive packets between the

fragments. Each MLP bundle has multiple transmit packet queues. MLP does not interleave packet

fragments from different packet queues associated with a given MLP bundle. Instead, MLP transmits all

of the fragments associated with a nonreal-time packet in order before transmitting fragments from

another nonreal-time packet. MLP posts all of the packets from the various nonreal-time packet queues

to a single bundle first-in first-out (FIFO) queue. It is from this single bundle queue that MLP does the

Real-time traffic, such as voice, are queued intact to a priority (low-latency) queue. It is from this queue

that MLP transmits the real-time packets and interleaves them between the nonreal-time fragments.

Because real-time packets are not MLP encapsulated or fragmented, MLP can safely interleave these

packets as needed. Traffic transmitted from the priority queue takes precedence over the MLP

encapsulated traffic that is transmitted from the related bundle queue.

Delay Insensitive

Packet Queues

Delay Sensitive

Packet Queues

The purpose of MLP over ATM-based LFI receive processing is to reassemble MLP over ATM

encapsulated packet fragments into PPP over ATM packets. During receive processing, the fragments

that arrive out of order and the packets with missing fragments are discarded. Valid fragments are merged

in memory until the entire packet is reassembled.

Fragments nonreal-time traffic

Encapsulates the fragments with MLP

Transmits the fragments

shows an example of the packet flow of real-time and nonreal-time packets.

MLP Over ATM-Based LFI Packet Queue Flow

Multilink PPP-Based Link Fragmentation and Interleaving

Cisco 10000 Series Router Quality of Service Configuration Guide

Table of Contents