PppStats signal equivalent in NM-0.9

[Daniel Drake <dsd laptop org>]

Hi,

NetworkManager-0.8 had a PppStats signal on the
org.freedesktop.NetworkManager.Device.Serial interface to show total
TX/RX bytes. Sugar used this to show bandwidth usage counters - quite
useful in the kinds of environments where modems might be used on OLPC
laptops (expensive bandwidth costs).

I can't see an equivalent in NetworkManager-0.9. Is there one, or an
alternative way of getting such info?

Thanks
Daniel