Juniper ACX2000 Configuration Guide

Guidelines for Configuring MLPPP With LSQ Interfaces on ACX Series Routers
You can configure MLPPP bundle interfaces with T1/E1 member links. The traffic that is
transmitted over the MLPPP bundle interface is spread over the member links in a
round-robin manner. If the packet size is higher than the fragmentation size configured
on the MLPPP interface, the packet are fragmented. The fragments are also sent over
member links in a round-robin pattern. The PPP control packets received on the interface
are terminated on the router. The fragmentation size is configured at the MLPPP
bundle-level. This fragmentation size is applied to all the packets on the bundle, regardless
of the multilink class.
Multiclass MLPPP segregates the multilink protocol packets in to multiple classes. ACX
routers support up to a maximum of four classes. One queue is associated with each of
the four classes of multiclass MLPPP (MCML). The packets can be classified to be part
of one of the classes. These packets take the queue associated with the class. The
packets inside a queue are served in first-in first-out (FIFO) sequence.
Multiclass MLPPP is required to provide preferential treatment to high-priority,
delay-sensitive traffic. The delay-sensitive smaller real-time frames are classified such
that they end up in higher priority queue. While a lower priority packet is being fragmented,
if a higher priority packet is enqueued, the lower priority fragmentation is suspended, the
higher priority packet is fragmented and enqueued for transmission, and then the lower
priority packet fragmentation is resumed.
Traditional LSQ interfaces (anchored on PICs) are supported to combine T1/E1 interfaces
in an MLPPP bundle interface. Inline services (si-) interfaces and inline LSQ interfaces
are not supported in MLPPP bundles. On ACX routers, MLPPP bundling is performed on
the TDM MICs and traditional LSQ model is most effective mechanism. You can configure
channelized OC interfaces (t1-x/y/z:n:m, e1-x/y/z:n) as members of an MLPPP bundle
interface. A maximum of 16 member links per bundle is supported. The MPLS, ISO, and
inet address families are supported. The ISO address family is supported only for IS-IS.
You can configure MLPPP bundles on network-to-network interface (NNI) direction of
an Ethernet pseudowire. Interleaving using multiclass MLPPP is supported.
Keep the following points in mind when you configure MLPPP bundles on ACX routers:
•
The physical links must be of the same type and bandwidth.
•
Round-robin packet distribution is performed over the member links.
•
To add a T1 or E1 member link to the MLPPP bundle as link services LSQ interfaces,
include the bundle statement at the [edit interfaces t1-fpc/pic/port unit
logical-unit-number family mlppp] hierarchy level:
[edit interfaces t1-fpc/pic/port unit logical-unit-number family mlppp]
bundle lsq-fpc/pic/port.logical-unit-number;
•
To configure the link services LSQ interface properties, include the following statements
at the [edit interfaces lsq-fpc/pic/port unit logical-unit-number] hierarchy level:
[edit interfaces lsq-fpc/pic/port unit logical-unit-number]
encapsulation multilink-ppp;
509Copyright © 2017, Juniper Networks, Inc.
Chapter 17: Configuring MLPPP

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English