Hi, Qilei, Ramon and all,
I think Ramon provides a straightforward solution to this requirement. But
I would like to step back and ask: whether we should specify the domain
diversity in PCEP for H-PCE or not? As we can see not all requirements
specified in H-PCE RFC are accommodated in draft-ietf-pce-hierarchy-extensions
(e.g., Setion 1.1.).
According to Section 1.3.2 in RFC6805, domain diversity can facilitate path
diversity. If this is the only reason, what currently defined in RFC5440
accommodates this need already, right? If the source node only wants path
diversity but specify domain diversity, it may end up with no path available,
assume there is one transit domain all paths will have to go through from the
source domain. On the other hand, if the source node only specifies path
diversity, it may or may not get a domain-diversified path, which can be
decided by the parent PCE.
Any thoughts?
Regards,
Xian
From: [email protected] [mailto:[email protected]] On Behalf Of
[email protected]
Sent: 2013年9月13日 15:27
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.
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