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. 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
