If you have two frame relay line between two location and you need these lines to balance the load, then this article will guide you. We need two techniques to do it. First one is multilink PPP, which can be used to bundle leased lines. The second one is PPP over Frame Relay, which lets frame relay lines used like leased lines.

In my example, I will show how I bundle two 2 Mbps frame relay line to act as one 4 Mbps line.

We have to do below configuration on both sides.

1)We will make an ordinary frame relay configuration on serial interfaces except “frame-relay interface-dlci 16 ppp Virtual-Template1” line. Here we are adding Virtual-Template1. frame-relay traffic-shaping command is a MUST.
2)Under “interface Virtual-Template1“, we describe that it is a part of multilink interface
3)Under “interface Multilink1” we will configure IP settings.

interface Serial0/0
description Physical Interface 1
bandwidth 2000
no ip address
encapsulation frame-relay
frame-relay fragmentation voice-adaptive deactivation 15
frame-relay traffic-shaping
frame-relay interface-dlci 16 ppp Virtual-Template1
frame-relay lmi-type ansi

interface Serial0/1
description Physical Interface 2
bandwidth 2000
no ip address
encapsulation frame-relay
frame-relay fragmentation voice-adaptive deactivation 15
frame-relay traffic-shaping
frame-relay interface-dlci 16 ppp Virtual-Template1
frame-relay lmi-type ansi

interface Virtual-Template1
no ip address
ppp multilink
ppp multilink group 1

interface Multilink1
description Bundled Interface
bandwidth 4000
ip address 10.87.1.1 255.255.255.248
ppp multilink
ppp multilink group 1