Hi Xiaohu, I agree that RFC5512 alone can't solve the problem because of the reason you pointed out. Using extcommunity is an option for an operator who owns multiple ASes to form Inter-AS softwire mesh inside its domain. However, you may also want to mention that two different operators may want to directly peer to each other for Inter-AS softwire because creating softwire requires resource, an operator may want to have explicit peering relationship to another operator to form the mesh.
Regards, Yiu On 7/30/10 5:30 AM, "xuxiaohu 41208" <[email protected]> wrote: > Hi all, > > The abstract of RFC5512 (The BGP Encapsulation Subsequent Address Family > Identifier (SAFI) and the BGP Tunnel Encapsulation Attribute) is as follows: > > Abstract > > In certain situations, transporting a packet from one Border Gateway > Protocol (BGP) speaker to another (the BGP next hop) requires that > the packet be encapsulated by the first BGP speaker and decapsulated > by the second. To support these situations, there needs to be some > agreement between the two BGP speakers with regard to the > "encapsulation information", i.e., the format of the encapsulation > header as well as the contents of various fields of the header. > > According to RFC5512, the tunnel is started from one BGP router and terminated > another (i.e. the BGP next hop), unless ensuring that an ASBR that is not an > AFBR does not change the next hop of the E-IP routes (i.e., option 3 for > inter-AS softwire described in Softwire Mesh Framework [RFC5565]), RFC5512 > alone can not be used to support inter-AS softwire mesh. > > As I mentioned during my presentation, the option 3 described in RFC5565 > requires all non-AFBR ASBRs to be upgraded in order to support this > capability. In contrast, our approach has not such limitation since we use a > transitive Extended Community attribute to carry the tunnel endpoint address. > > Best wishes, > Xiaohu > > > > > _______________________________________________ > Softwires mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/softwires _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
