Configuring Multilink Frame Relay; Overview; T1/E1 Connections - Juniper JUNOSE SOFTWARE 11.0.X - LINK LAYER CONFIGURATION GUIDE 4-1-2010 Configuration Manual

Chapter 3

Configuring Multilink Frame Relay

Overview

T1/E1 Connections

This chapter describes how to configure Multilink Frame Relay (MLFR) interfaces on
E Series routers.
This chapter contains the following sections:
Overview on page 133
Platform Considerations on page 135
References on page 136
Supported MLFR Features on page 136
Unsupported MLFR Features on page 137
Before You Configure MLFR on page 138
Configuration Tasks on page 138
Monitoring MLFR on page 140
MLFR aggregates multiple physical links into a single logical bundle. More specifically,
MLFR bundles multiple link-layer channels into a single network layer channel.
The routers joined by the multilink each assign the same unique name to the bundle.
A bundle can consist of multiple physical links of the same type such as multiple
asynchronous lines or can consist of physical links of different types such as leased
synchronous lines and dial-up asynchronous lines.
The router treats MLFR like nonmultilink Frame Relay. Packets received with an
MLFR header are subject to sequencing. Packets received without the MLFR header
cannot be sequenced and can be delivered only on a first-come, first-served basis.
Some users need more bandwidth than a T1 or an E1 channel can provide, but cannot
afford the expense or do not need the bandwidth of T3 or E3. Equal-cost multipath
(ECMP) is one way to achieve a bandwidth greater than DS1 service without going
to the expense and infrastructure required for DS3 service. MLFR is commonly used
as an alternative to ECMP to deliver NxT1 service. Cost-analysis of NxT1 versus DS3
service typically imposes a practical limit of 8xT1 service; that is, aggregation of no
more than eight T1 or E1 connections into an MLFR bundle.
133
Overview