|As far as I am aware, the following algorithms have been |officially proposed: | | a) Sequential method: port-set is a range of consecutive ports. (See | I-D.matsuhira-sa46t-spec-03.) | | b) Modulo method: port-set for 1st CPE is (0, N, 2*N, ...), |port-set for | 2nd CPE is (1, N+1, 2*N+1, ...) and so on, where N is the |number of CPEs | sharing the same IPv4 address. (See I-D.xli-behave-divi-03.) | | d) "New 4rd method" (interleaved port-pairs): port-set for |the 1st CPE is | (0, 1, 2*N, 2*N+1, 4*N, 4*N+1, ...), where N is the number of CPEs | sharing the same IPv4 address. (See |I-D.despres-softwire-4rd-addmapping-00.) | | d) "Old 4rd method" (interleaved port-ranges of different |sizes): port-set | for the 1st CPE is: | ([4k..4k/N], [8k..8k/N], [16k..16k/N], [32k..32k/N]), | for the 2nd CPE is: | ([4k+4k/N..4k+2*4k/N], ..., [32k+32k/N..32k+2*32k/N]), | where N is the number of CPEs sharing the same IPv4 address. (See | I-D.murakami-softwire-4rd-00.) | | e) Random method: port-set is a randomly chosen subset of all |available ports. | (See I-D.boucadair-pppext-portrange-option-07.) | | f) Port-range-mask method: port-set is a range of consecutive |ports or a | set of ranges of consecutive ports. (See | I-D.boucadair-pppext-portrange-option-07.) | |If I forgot something, please let me know. It would be also
One more port allocation method documented in separated documents, by which different deployment scenarios and possible provisioning means are elaborated : Deploy this method in DS-Lite context: draft-zhou-softwire-b4-nat-02 Deploy in A+P context: draft-deng-v6ops-aplusp-experiment-results-01 A possible provisioning means - PCP: draft-tsou-pcp-natcoord-03 Cheers, Xiaohong |nice to compare all these algorithms and to identify the |trade-offs. The mechanism drafts would then just pick one of |these algorithms (without the need to define it again) and |justify the decision for the specific algorithm. | |What do you think about this proposal? With my colleagues we |are preparing another port-selection algorithm, which would |enhance the security for stateless solutions. Something like a |stateless-ready counterpart to the Random method, specified in |I-D.boucadair-pppext-portrange-option-07. This way we could |just add such an algorithm to this "algorithms document" and the |IPv4 address sharing mechanism document authors could then |choose the one which suits them best. | |Thanks, |Nejc | _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
