Proposed text is good to me. Thanks, Lucy -----Original Message----- From: Thomas Narten [mailto:[email protected]] Sent: Friday, October 18, 2013 4:53 PM To: Lucy yong Cc: [email protected] Subject: Distributed Gateways [was Re: [nvo3] NVO3 Architecture document]
Hi Lucy. Lucy yong <[email protected]> writes: > Section 5.3 describes gateways. IMO: it misses an important use case. > A Gateway, say overlay gateway, may be used to interconnect two or > more overlay VNs. In this case, the traffic traversing between two > overlay VNs must go through the gateway where the policy can be > enforced. Furthermore, it is possible to implement centralized or > distributed overlay gateway. The latter has overlay gateway function > implemented on NVEs. Thus, it requests the cross-VN policies to be > distributed to NVEs. > Current section seems very focus on overlay VN interconnect a > non-overlay network, which centralized gateway architecture is > practical. But in overlay networks, both centralized or distributed > are possible and depend on the applications. Agreed. I propose adding a new section after 5.3 that says: <section title="Distributed Gateways"> <t> The relaying of traffic from one VN to another deserves special consideration. The previous section described gateways performing this function. If such gateways are centralized, traffic between TSes on different VNs can take suboptimal paths, i.e., triangular routing results in paths that always traverse the gateway. As an optimization, individual NVEs can be part of a distributed gateway that performs such relaying, reducing or completely eliminating triangular routing. In a distributed gateway, each ingress NVE can perform such relaying activity directly, so long as it has access to the policy information needed to determine whether cross-VN communication is allowed. Having individual NVEs be part of a distributed gateway allows them to tunnel traffic directly to the destination NVE without the need to take suboptimal paths. </t> <t> The NVO3 architecture should [must? or just say it does?] support distributed gateways. Such support requires that NVO3 control protocols include mechanisms for the maintenance and distribution of policy information about what type of cross-VN communication is allowed so that NVEs acting as distributed gateways can tunnel traffic from one VN to another as appropriate. </t> </section> Thoughts? Thomas _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
