[c-nsp] Basic understanding of 6PE and 6VPE

[adam vitkovsky]

I'm sure there were a lot of factors that influenced the decision on whether
the support IPv6 natively or not 

Like how big was the network and how fast it needed to be up to speed with
regards to IPv6 services -as well as expenses associated with the migration

Merely by comparing the number of devices that needs to be touched, Tier 2
ISP configuring the whole backbone to support native IPv6 can take
comparable amount of time as Tier 1 ISP configuring their PEs and RRs for
6VPE (assuming Opt.C is in place thus no need for ASBRs to be touched) 

>Not all customers who run across your MPLS network are buying l3vpn
services.
Right but it's easier (though not perfect) to offer transit Internet
services as another L3VPN service if you are already running a huge MPLS
inter-networks than building up a separate infrastructure to support the
service 


adam