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Re: Please comment draft-kulmala-l3vpn-aggregation-pe-00

Marko,

Option B requires that there is a label switched path leading from a
packet's ingress PE to its egress PE as stated in RFC2547bis. There is
no IP layer forwarding at ASBR. In my mind that is then the same mpls
domain, but word "domain" may mean different things to us.

Nope ... LSP terminates when the next hop is being changed. In option B ASBRs change next hops on the vpnv4 routes so LSP terminates there. The LSP switching looks like:

PEing --- ASBR --- ASBR ---- PEegr

or

PEing --- ASBR --------------PEegr

depending on how you deal with next hop configuration on ASBRs.

In option C indeed there is no next hop change across domains and one could say that it requires inter-mpls LSP to work between ing & egr PEs.

Let me also point out that MPLS LSP is not a must requirement for any 2547 inter-as (or intra as) transport. You can easily substitute it with IP tunnels which therefor would not require any MPLS state in the domain chain of PE-PE path.

But anyways there is LSP connectivity between routers in different ASes.
As stated earlier I think that what we propose would give better
isolation than option B.

I think I still haven't seen why option A is not sufficient then if strong intra-domain isolation is a requirement ? It seems to me it is very close to what you are proposing ... especially when draft provides an example of the complete modifications to the RD & RTs.

Cheers,
R.