The MPLS WG Archive

["Nagabhushana Ramaswamy Nadig" <nagabhushana.ramaswamy@wipro.com>]

Hello Manoj,
	Please also note that it is made mandatory in the rfc that if a
mapping message is a response to a request message then the sender should
include the Label Request id TLV in the mapping message. By this request
id you will be able to map the mapping to a unique request message.

regards
Bhushana

> Hi,
>
> In RFC 3036 section A.1.2 ,LMp.18, Note 8, it is mentioned that if
> LSR is not merging, then it may have sent label mapping for LSP in
> question to at most one LSR.  Lets take the following scenario :
>
> LSR A is non merge capable and operating in DoD advertisement mode with
> independent control. Now, it may receive requests from multiple LSRs say
> LSR B, LSR C etc. Since, it is using independent control, it may send
> mapping (different labels) to LSRs B & C immediately without waiting for
> a mapping from its next hop (offcourse it will send requests to next hop
> for each such mapping). Also, it may so happen that LSR B is also non
> merge capable and it may send multiple requests to A (one for each of
> B's upstream peers). In this case, we might end up in a situation where
> A has send multiple uniquely distinct mappings to B and one (or
> more) uniquely distinct  mappings to C for the same FEC. Now, when
> A receives a mapping from its next hop for the FEC in question, we see
> that Note 8 as enumerated above is clearly violated as there is more
> than one LSR (in this case B & C) for which A has previously sent a
> mapping.
> Let me know if there is some inconsistency in the above mentioned line
> of reasoning.
>
> Thanks in advance
> manoj
>
>
>