Hi, Qin: I guess the sentences in section 1.3.2.2 of RFC6805 can answer you question, I cite them here,
" A pair of paths are domain-diverse if they do not transit any of the same domains. A pair of paths that share a common ingress and egress are domain-diverse if they only share the same domains at the ingress and egress (the ingress and egress domains). Domain diversity may be maximized for a pair of paths by selecting paths that have the smallest number of shared domains. " Thanks Qilei Wang Qin Wu <[email protected]> 2013-09-13 15:46 收件人 "[email protected]" <[email protected]>, Ramon Casellas <[email protected]>, 抄送 "[email protected]" <[email protected]> 主题 RE: [Pce] A comment regarding domain diversity in draft-ietf-pce-hierarchy-extensions Hi, Qilei: For domain diversity, when path computation traverses multiple domains including one ingress domain, multiple transit domains, one egress domain, there are several cases: a. Computation path share none of these domains. b. Computation path only shares both ingress domain and egress domain but not share any transit domains. c. Computation path only shares ingress domain but not share any transit domain and egress domain. d. Computation path only shares egress domain but not share any transit domain and ingress domain. I am wondering which case you are referred to ? Regards! -Qin From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Friday, September 13, 2013 3:27 PM To: Ramon Casellas Cc: [email protected] Subject: Re: [Pce] A comment regarding domain diversity in draft-ietf-pce-hierarchy-extensions Hi, Ramon, Thank you for pointing the RFC6007 to me. I almost forgot this draft. Yeah, you are right. This requirement can be satisfied by two approaches. One is the 2-step approach which can be addressed by IRO/XRO, and the other is the "D flag" in SVEC object in the H-PCE scenario according to your mail. Just from my opinion, the new flag indicating "domain diverse" in SVEC object is needed in PCEP protocol. Thanks Qilei Wang Ramon Casellas <[email protected]> 发件人: [email protected] 2013-09-13 12:48 收件人 [email protected], 抄送 主题 Re: [Pce] A comment regarding domain diversity in draft-ietf-pce-hierarchy-extensions Just from my understanding, maybe this requirement can be resolved by extending the PCEP object to indicate "domain-diverse" requirement when PCE computes a pair of dependent path at the same time. When PCC sends path request to child PCE, this requirement can be indicated in the path request message, and child PCE can forward this requirement indication to the parent PCE. Parent PCE has the topology information of domains, so it is able to compute two domain-diverse paths. Hi Qilei, all Would, for example, a new bit in the SVEC saying "domain diverse" fulfill such requirement? I was reading http://tools.ietf.org/html/rfc6007 sect 5.3 that discusses this. The two step can be addressed by IRO/XRO and the common H-PCE case could use a D flag. Domain sub-objects are not domain-specific 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Flags |D|S|N|L| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Request-ID-number #1 | // // | Request-ID-number #M | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Thoughts? thanks, R. _______________________________________________ Pce mailing list [email protected] https://www.ietf.org/mailman/listinfo/pce
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