Hi Bruno, So you suppose the label used in an RG cannot be used again out of the RG. That is not correct. Please find my comments inline [Mingui].
<snip> >[Bruno2] Let's assume: >- 5 PE in the group, hence sharing the same range of labels (e.g., 1~1100). >- 5 VPNs in connect to this group of PE, 2 of which being dual-homed (VPN1 & >VPN2). > >With label sharing: >Label:1 2 3 4 5 > >PE1 VPN1 x x x x >PE2 VPN1 VPN2 x x x >PE3 x VPN2 x x x >PE4 x x VPN3 x x >PE5 x x x VPN4 VPN5 > >All labels marked as "x" are burned/lost because of the label sharing. [Mingui] Not true. Where we got this constraint? For an explicitly example, PE4 can well use label 1,2,4,5. [Mingui] I anticipate you assume PE1~PE5 are forming an RG, so that once a label is used it is used across the RG. I need to point out that the unit of "RG" is independent of PEs. It depends on the VPN connections. I saw Zhou Peng has already given examples on this point. <snip> >[Bruno2] not always. There is public/ietf example for this: >draft-l3vpn-legacy-rtc-00 [Mingui] It's designed to be incrementally deployable in the network. The trick is confined in the RG. Other P and PE routers are unaware of the change. [Mingui] I guess you may change to imagine the scenario that operator need a legacy PE and a label sharing PE form an RG. Let's consider the analogy that the operator interconnects two switches using LAG while one of them does not support LAG at all. :) [Mingui] Thanks for continuing the discussion. I think the discussion about label ranges reservation in another thread is related to our discussion. To my understanding, the conclusion is that it's not OK to require a label block to be supported across multiple PEs. A possible escape is to resort to a higher-layer authorized entity out of the RG to assign the label. Thanks, Mingui
