From: "Joe Abley"
If that's right, then unless that tunnel switch is spectacularly transparent with respect to encapsulated frame (and maybe it is) then some explicit v6 support seems like it is required within Telecom's network for v6 customer access to work.
Telecom's UBS configuration is (AFAIK) Cisco's "vpnd multihop". Their LAC/LNS talks PPP with the DSL device up to the AUTH stage, pumps the AUTH data to a Radius server which looks at the physical stuff in the data (like DSLAM ID and port) to decide on the next hop LNS. You then get the hack/proxy LCP/PAP exchange between Telecom's LAC/LNS and the ISP's LNS to get up to the IPCP stage and from there on all PPP packets are exchanged between the DSL device and the ISP's LNS. So what ever PPP supports beyond the AUTH stage should be available, the limitation being that you have very little control over LCP parameters (e.g. MRU) unless you can force a restart of LCP with the DSL device. Protocols that rely on secure Auth (e.g. some PPP payload encryption schemes) won't work. No reason why IPv6 won't work tho, only issue I can see is MRU type stuff. Cheers BG