On R2 s1/2 fragment the frames to 240 bytes.  Make sure to interleave the frame. Assume that the link is 128k.



R2#sh run int mu 1
Building configuration...

Current configuration : 164 bytes
!
interface Multilink1
 ip address 180.40.7.2 255.255.255.224
 ppp multilink
 ppp multilink fragment delay 15
 ppp multilink interleave
 ppp multilink group 1
end

R2#sh run int s1/2
Building configuration...

Current configuration : 117 bytes
!
interface Serial1/2
 no ip address
 encapsulation ppp
 clock rate 64000
 ppp multilink
 ppp multilink group 1
end


R3#sh run int mu 1
Building configuration...

Current configuration : 222 bytes
!
interface Multilink1
 ip address 180.40.7.1 255.255.255.224
 ppp multilink
 ppp multilink fragment delay 15
 ppp multilink interleave
 ppp multilink group 1
 max-reserved-bandwidth 100
 service-policy output Prob11
end

R3#sh run int s1/2
Building configuration...

Current configuration : 99 bytes
!
interface Serial1/2
 no ip address
 encapsulation ppp
 ppp multilink
 ppp multilink group 1
end


R3#debug ppp multilink