Tom, et, al, thanks for the suggestion. I would lean towards pushing back on rewriting section 5, on the grounds that this is a set of generic tools and that specific use cases rather could go in a deployment document.
does anyone else have strong opinions on current text versus Tom's proposed changes? cheers, Ole On Feb 21, 2013, at 16:43 , Tom Taylor <[email protected]> wrote: > The two bullets below were actually a "Trojan Horse" of sorts. They set the > agenda for Sections 5.2 and 5.3 respectively. I think those two sections > should have different titles to start with: > > 5.2 Provisioning the MAP IPv4 Address, MAP IPv6 Address, and Port Set > Identifier (PSID) At a CE > > 5.2.1 Deriving the IPv4 Address and PSID From the End-User IPv6 Prefix and > the Basic Mapping Rule > > 5.2.2 Deriving the IPv6 Address To Use On the MAP Interface > > 5.3 Deriving the MAP IPv6 Address From the IPv4 Address and Port and the > Matching Forwarding Mapping Rule (Mesh Mode Only) > > The procedure described in each section should then match the title. I'll > sketch the flow here, but I can supply detailed text if desired. > > > 5.2.1 Deriving the IPv4 Address and PSID From the End-User IPv6 Prefix and > the Basic Mapping Rule > > - distinguishing the Basic Mapping Rule (BMR) from other mapping rules that > are provisioned > > - locating the Extended Address (EA) bits in the End-User IPv6 Prefix > > - Case 1: Port set identifier (PSID) is explicitly provisioned separately > from the BMR > -- IPv4 address is shared > -- IPv4 address is the concatenation of the IPv4 prefix provided in the BMR > and the IPv4 suffix provided by the EA bits > -- if the result is not a /32, error > > - Case 2: PSID is embedded in the EA bits > -- true if the sum (o + r) is greater than 32, where o is the number of EA > bits as indicated by the BMR, and r is the length of the IPv4 prefix supplied > by the BMR > -- shared IPv4 address is the concatenation of the IPv4 prefix supplied by > the BMR and as many of the high-order bits within the EA bit field as > required to make up a /32 > -- PSID is given by the remaining lower-order bits in the EA bit field > > - Case 3: non-shared IPv4 address or prefix > -- true if the sum (o + r) as defined above is less than or equal to 32 > -- IPv4 address or prefix is equal to the concatenation of the IPv4 prefix as > supplied by the BMR with the entire contents of the EA bit field. > > 5.2.2 Deriving the IPv6 Address To Use On the MAP Interface > > - MAP IPv6 address is given by the concatenation of the provisioned End-User > IPv6 Prefix with an interface identifier derived as described in Section 6. > > - this applies for both hub-and-spoke and mesh mode > > 5.3 Deriving the MAP IPv6 Address From the Destination IPv4 Address and Port > and the Matching Forwarding Mapping Rule (Mesh Mode Only) > > - locate the applicable Mapping Rule by longest match on rule IPv4 > address/prefix > > - Derive the target End-User IPv6 prefix less the subnet identifier as > follows: > > -- Case 1: length of the EA field as given by the selected Mapping Rule is 0 > --- target End-User IPv6 prefix (less the subnet identifier) is equal to the > IPv6 prefix provided by the selected Mapping Rule > > -- Case 2: sum (o + r) is less than or equal to 32, where o and r are as > defined in Section 5.2 > --- implies destination IPv4 address/prefix is dedicated to destination CE > --- EA bit field is equal to the highest-order o bits of the destination IPv4 > address not contained in the IPv4 address/prefix provided by the selected > Mapping Rule > --- target End-User IPv6 prefix (less the subnet identifier) is equal to the > IPv6 prefix provided by the selected Mapping Rule followed in concatenation > with the derived EA bit field > > -- Case 3: sum (o + r) as defined above is greater than 32 > --- implies destination IPv4 address/prefix is shared > --- set the high-order portion of the EA bit field equal to the low-order (32 > - r) bits of the destination IPv4 address > --- the remaining o - (32 - r) bits of the EA bit field are equal to the > high-order bits of the destination port number, beginning with the bit after > the offset given by the selected Mapping Rule (default = 6) > --- target End-User IPv6 prefix (less the subnet identifier) is equal to the > IPv6 prefix provided by the selected Mapping Rule followed in concatenation > with the derived EA bit field > > - subnet identifier portion of the End-User IPv6 prefix is all zeroes > > - End-User MAP Address is equal to the End-User IPv6 prefix concatenated with > an interface identifier (IID) derived as described in Section 6. > > Tom Taylor > > > On 13/02/2013 3:07 AM, Ole Troan wrote: >> I agree with Tom's proposed changes. >> I'll put them in a upcoming revision 05, if no-one objects. >> (I still think we can do a WGLC on revision 04). >> >> cheers, >> Ole >> >> >>> Remark: I'm not sure the two bullets (quoted further down) tell the full >>> story as they stand. I propose to modify them as follows: >>> >>> 1. Basic Mapping Rule (BMR) - mandatory. There can only be one >>> Basic Mapping Rule per End-user IPv6 prefix. In combination >>> with the End-user IPv6 prefix, the Basic Mapping Rule is used >>> to derive the IPv4 prefix, address, or shared address and >>> the PSID assigned to the CE. >>> >>> 2. Forwarding Mapping Rule (FMR) - optional, used for forwarding. >>> The Basic Mapping Rule is also a Forwarding Mapping Rule. Each >>> Forwarding Mapping Rule will result in an entry in the Rules >>> table for the Rule IPv4 prefix. Given a destination IPv4 address >>> and port within the MAP domain, a MAP node can use the matching >>> FMR to derive the End-user IPv6 address of the interface through >>> which that destination address-port combination can be reached. >>> >>> >>> On 12/02/2013 9:22 AM, Ole Troan wrote: >>>> Tom, >>>> >>>>> Thanks. What about the assertions in the bullets? >>>> >>>> sorry, may be my short term memory... what do you mean? >>>> >>>> cheers, >>>> Ole >>>> >>>> >>>>> >>>>> On 12/02/2013 3:27 AM, Ole Troan wrote: >>>>>> Tom, >>>>>> >>>>>>> I'm still hoping to see a response to this. >>>>>>> >>>>>>> On 06/02/2013 8:42 AM, Tom Taylor wrote: >>>>>>>> Section 5 of the latest version of MAP has the following: >>>>>>>> >>>>>>>> 1. Basic Mapping Rule (BMR) - mandatory, used for IPv4 prefix, >>>>>>>> address or port set assignment. There can only be one Basic >>>>>>>> Mapping Rule per End-user IPv6 prefix. The Basic Mapping Rule >>>>>>>> is >>>>>>>> used to configure the MAP IPv6 address or prefix. >>>>>>>> >>>>>>>> 2. Forwarding Mapping Rule (FMR) - optional, used for forwarding. >>>>>>>> The Basic Mapping Rule is also a Forwarding Mapping Rule. Each >>>>>>>> Forwarding Mapping Rule will result in an entry in the Rules >>>>>>>> table for the Rule IPv4 prefix. >>>>>>>> >>>>>>>> Question: there will always be a BMR. In the absence of additional >>>>>>>> rules, how does a CE know whether it can use the BMR for forwarding or >>>>>>>> must always use the default rule? >>>>>> >>>>>> the answer to that is in section 7, last bullet. >>>>>> >>>>>> that is, the MAP CE must be configured to be in hub and spoke mode or >>>>>> mesh mode. >>>>>> which mode it is in decided if the BMR is used for forwarding or not. >>>>>> >>>>>> 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
