I checked from Feature Navigator

Following features seems to be NOT-SUPPORTED for 878 G.SHDSL

Class Based Weighted Fair Queuing (CBWFQ)

Routed Bridge Encapsulation with ATM Virtual Circuit Bundles

Is there any other way?

CBWFQ is not what you're doing (MQC)

You are not using VC bundles.

Configure a explicit traffic paramenters as indicated above and let us know.

I am using

(C870-ADVIPSERVICESK9-M), Version 12.4(15)T4, RELEASE SOFTWARE (fc2)

I apply following commands

Router(config)#interface ATM0.100 point-to-point

Router(config-subif)# ip address 1.1.2.2 255.255.255.252

Router(config-subif)# atm route-bridged ip

Router(config-subif)# pvc 0/35

Router(config-if-atm-vc)# encapsulation aal5snap

Router(config-if-atm-vc)# service-policy output WAN-EDGE

Router(config-if-atm-vc)#cbr 128

The commands does not output any error

But I cannot see "-policy output WAN-EDGE" command from running-config.

Router#sh running-config

!

class-map match-any Call-Signaling

match ip dscp cs3

match ip dscp af31

class-map match-all Voice

match ip dscp ef

!

!

policy-map WAN-EDGE

class Voice

priority percent 33

compress header ip rtp

class Call-Signaling

bandwidth percent 5

class class-default

fair-queue

policy-map SHAPE-WAN-EDGE-128

class class-default

shape average 128000

service-policy WAN-EDGE

!

!

bridge irb

!

!

interface BRI0

no ip address

encapsulation hdlc

shutdown

!

interface ATM0

mtu 1500

no ip address

no atm ilmi-keepalive

!

interface ATM0.100 point-to-point

ip address 1.1.2.2 255.255.255.252

atm route-bridged ip

pvc 0/35

cbr 128

encapsulation aal5snap

!

That is not normal, you can try another image otherwise I recommend you engage TAC on the matter. Anyway since it's a poin to point circuit, why don't you use regual aal5mux encap for maximum efficiency.

Also, ip rtp compress and bridge IRB are not doing anything for you.