Has anyone use rtp header compression?

tcp header compression or ip rtp header compression?
im using g.711 for my remotes offices that only have 1 ip phone, im getting an average of 110 to 120kb per call i know g.729 take about 30-40k but they want the best posible voice quality, would the compression compress the voice packet a good amount of size of it really stays the same?
im using g.711 for my remotes offices that only have 1 ip phone, im getting an average of 110 to 120kb per call i know g.729 take about 30-40k but they want the best posible voice quality, would the compression compress the voice packet a good amount of size of it really stays the same?
Comments
You will need to have cRTP configured on both sides of the link and I believe it is only supported over PPP, HDLC and Frame Relay serial links so that would rule out your connections.
class-map VOICE
match protocol rtp
Policy-map VOICE
class VOICE
Compression header ip rtp
inter s1/0
service-policy output VOICE
you can even prioritize voice traffice by using the priority command under the policy-map