Does the "interface multilink x" have to be created in order for the traffic to be balanced across the two links? Because when I did it the following way (with a similar configuration for R2) by turning on "frame-relay traffic-shaping" at the physical interface level and "ppp multilink" on the virtual-interface it seems to work ok. The "show frame pvc x" down the bottom show the counters increasing on both PVC when an extended ping with 1500B packets was sent from R2 to R3. (?)
interface Serial0/0/0
no ip address
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 302 ppp Virtual-Template2
no frame-relay inverse-arp
frame-relay lmi-type cisco
interface Serial0/2/0
no ip address
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 312 ppp Virtual-Template2
no frame-relay inverse-arp
interface Virtual-Template2
ip address 174.17.23.3 255.255.255.0
ppp authentication chap
ppp chap hostname Rack17R3
ppp chap password 0 CISCO
ppp multilink
Rack17R3#sh ppp multilink
Virtual-Access4, bundle name is Rack17R2
Username is Rack17R2
Endpoint discriminator is Rack17R2
Bundle up for 00:14:31, total bandwidth 56, load 1/255
Receive buffer limit 24384 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 1075 reordered
0/0 discarded fragments/bytes, 0 lost received
0x3E82 received sequence, 0x3E82 sent sequence
Member links: 2 (max not set, min not set)
Vi1, since 00:14:31
Vi3, since 00:14:31
No inactive multilink interfaces
Rack17R3#sh frame-relay pvc 312
PVC Statistics for interface Serial0/2/0 (Frame Relay DTE)
DLCI = 312, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/2/0
input pkts 4172 output pkts 3992 in bytes 402162
out bytes 388201 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
5 minute input rate 5000 bits/sec, 7 packets/sec
5 minute output rate 5000 bits/sec, 7 packets/sec
pvc create time 03:20:30, last time pvc status changed 00:08:30
Bound to Virtual-Access3 (up, cloned from Virtual-Template2)
cir 56000 bc 7000 be 0 byte limit 875 interval 125
mincir 28000 byte increment 875 Adaptive Shaping none
pkts 3868 bytes 385861 pkts delayed 208 bytes delayed 21750
shaping active
traffic shaping drops 0
Queueing strategy: fifo
Output queue 0/40, 0 drop, 0 dequeued
Rack17R3#sh frame-relay pvc 302
PVC Statistics for interface Serial0/0/0 (Frame Relay DTE)
DLCI = 302, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0/0
input pkts 4529 output pkts 4561 in bytes 505959
out bytes 490640 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 203 out bcast bytes 67396
5 minute input rate 7000 bits/sec, 9 packets/sec
5 minute output rate 7000 bits/sec, 9 packets/sec
pvc create time 05:18:11, last time pvc status changed 00:08:35
Bound to Virtual-Access1 (up, cloned from Virtual-Template2)
cir 56000 bc 7000 be 0 byte limit 875 interval 125
mincir 28000 byte increment 875 Adaptive Shaping none
pkts 4191 bytes 420146 pkts delayed 307 bytes delayed 31533
shaping active
traffic shaping drops 0
Queueing strategy: fifo
Output queue 0/40, 0 drop, 0 dequeued