On Mar 31, 2011, at 11:55 PM, Yong Cui wrote: > Ole, > > The IPv4/IPv6 address mapping is stateful, which is the almost same as > DS-Lite does on address/port mapping, but simpler (i.e. Without port > mapping). > > Although L3TP is an important tunneling method, do you think IP-IP tunnels > are still widely used, including softwire mesh, DS-Lite, 6RD...? In order > to keep the simplicity, we really hope to use IP-IP tunnels in the > networks.
L2TP tunnels are absolutely in use today. - Mark > > Yong > > -----Original Message----- > From: Ole Troan <[email protected]> > Date: Thu, 31 Mar 2011 10:44:36 +0200 > To: "Lee, Yiu" <[email protected]> > Cc: "[email protected] list" <[email protected]> > Subject: Re: [Softwires] Questions on: draft-cui-softwire-host-4over6 > >> Yiu, >> >>> Ok. I agree with your definition. How about I rephrase it that dslite >>> and >>> 4over6 don't require control channel. RFC5571 requires control channel. >>> Can we agree that control channel requires extra overhead? >> >> absolutely. both encapsulation and signalling overhead. >> >> that does come with some benefits though, e.g. you can do authentication >> and so on. >> >> cheers, >> Ole >> >>>> Yiu, >>>> >>>>> The way to set up the tunnel is similar to ds-lite. The CPE will learn >>>>> the >>>>> TC's v6 address, then encap v4 packets into v6 to the TC. To create >>>>> the >>>>> v4-v6 mapping in the TC's routing table. This could be done by the TC >>>>> to >>>>> look at the dhcp message or by keepalive packets from the cpe. We >>>>> haven't >>>>> decided which way is preferred. But the tunnel itself is stateless. >>>> >>>> since we have tended to classify mechanisms into 'stateless' and >>>> 'stateful'. I think we need a common understanding of what mean by >>>> these >>>> terms. >>>> >>>> simply stated, if the mechanism scales by the number of >>>> subscribers/tunnels then it is stateful. if it scales by the amount of >>>> packets/traffic then it is stateless. >>>> >>>> if you agree with that definition I would think 4over6 is stateful, >>>> since >>>> it suggests to integrate the tunnel state into the RIB. i.e. you >>>> allocate >>>> a piece of memory per subscriber and you have to snoop on DHCP messages >>>> to refresh this state. >>>> >>>> cheers, >>>> Ole >>> >> >> _______________________________________________ >> Softwires mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/softwires > > > _______________________________________________ > Softwires mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/softwires _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
