You missed my point. I asked about a single label. You answered a label block question.
-- Jakob Heitz. On Nov 24, 2013, at 11:41 PM, "Mingui Zhang" <[email protected]> wrote: > Hi Jim & Jakob, > > I think you proposed a valid point. If we continue this proposal, we should > include an operational section. I believe this point applies to all such kind > of "fast egress PE node protection" schemes. > >> What if the primary PE comes online after the backup? >> What label should the backup use if it can not reach the primary? >> >> You need to think about partitioned networks too. > > If two PEs can reserved a label space to be used as the label range for > sharing, the proposal is workable. However, we can slightly relax this > constraint, i.e., PEs in an RG MUST reserve one label space for sharing. The > PEs in an RG just need a common available label range, right? There are > various ways to achieve this. For example, we can divide the label spaces > into several blocks beforehand. Give them priorities. When PEs locally > allocate labels, blocks with the higher priority will be used earlier. Then > PEs in an RG can agree on those common blocks with lower priorities. This > relaxation introduces flexibility. Imagine the case that an operator may be > not sure about the size of the label space to be reserved at the beginning. > In this way, even the primary come online after the backup, it can negotiate > a label range for sharing with the backup. > > At last but not least, even if PEs cannot find a common label range in the > worst case or the network is partitioned, the ICCP connection will not be > established. In this case, the PEs just fall back to the non redundant mode. > So the two scenarios proposed by Jakob can be handled. > > Anyway, I don't think there is no way to achieve such proposal. > > Thanks, > Mingui > >> -----Original Message----- >> From: L3VPN [mailto:[email protected]] On Behalf Of UTTARO, JAMES >> Sent: Friday, November 22, 2013 4:17 AM >> To: Jakob Heitz; Lizhenbin >> Cc: [email protected]; Stewart Bryant (stbryant) >> Subject: RE: Why we consider the method of "label sharing for fast PE >> protection" >> >> As I stated before an operational section that anticipates running the >> network >> would be useful in this discussion. I would like to see various scenarios, >> restrictions, failure modes etc.. >> >> Jim Uttaro >> >> -----Original Message----- >> From: Jakob Heitz [mailto:[email protected]] >> Sent: Thursday, November 21, 2013 3:09 PM >> To: Lizhenbin; UTTARO, JAMES >> Cc: [email protected]; Stewart Bryant (stbryant) >> Subject: RE: Why we consider the method of "label sharing for fast PE >> protection" >> >> What if the primary PE comes online after the backup? >> What label should the backup use if it can not reach the primary? >> >> You need to think about partitioned networks too. >> It's not as simple as you think. >> >> -- Jakob. >> >> -----Original Message----- >> From: Lizhenbin [mailto:[email protected]] >> >> It is not like this way. For the ICCP-based label allocation method, the >> primary PE >> is allocate the label for VPN by its own label allocation algorithm. The >> backup PE >> is just to allocate the label specified by the primary PE. The process is >> just like >> label backup. They need not use the same label allocation algorithm.
