Hi Aaron

Thanks for the comment.  There are no procedures defined that would allow a PCE 
to initiate a take-over of an LSP from a PCC.  Rather, the PCC must delegate 
the LSP to an appropriate PCE (if the LSP is initiated by a PCE then it must 
initially be delegated to that PCE).  The cases you mention would be resolved 
by the PCC making a local decision whether or not to re-delegate the LSP to an 
alternative PCE.

So, I am not sure that the "orphan" flag would be useful to the PCE, at least 
not for the purpose that you describe.

Best regards
Jon


-----Original Message-----
From: Pce [mailto:pce-boun...@ietf.org] On Behalf Of Aaron Itskovich
Sent: 04 January 2017 20:08
To: pce@ietf.org
Subject: Re: [Pce] draft-ietf-pce-pce-initiated-lsp


I suggest to add indication that PCE Initiated LSP is orphan to LSP object in 
PCReport message. This information will be useful in facilitating takeover of 
an orphan LSP by redundant PCE server.

Option 1) Adding bit to the LSP flags (L-bit "parentless/orphan") that will be 
set in the LSP object of the PCReport message sent when PCE Initiated LSP 
becomes orphan as result of connection loss to the PCE server that initiated 
this LSP or because such PCE server returns LSP delegation to the PCC to 
initiate transfer of LSP "ownership" to another PCE server.

Option 2) Adding bit to the LSP flags (D2-bit ) that is set when such LSP is 
delegated to any PCE server. In this option PCE receiving report will be able 
to derive when PCE Initiated LSP is in orphan state when C flag in the report 
is set and the new D2-bit is not set.


This proposal (regardless which option 1 or 2 is used ) alows PCC to propagate 
"orphan" state for the PCE initiated LSP to all PCE servers.  
It will help to trigger takeover of a PCE initiated LSP. The existing 
alternative is to rely on the PCE server to server communication for detection 
of such events which is prone to errors.

For example:

     - loss of communication between PCE-A and PCE-B may be interpreted as 
"takeover" trigger which is not necessarily true as PCE-A<->PCC connection may 
still be up.
     - In case where PCE-A <-> PCC connection is down and both PCC <-> PCE-B 
and  PCE-A <-> PCE-B connections are up we will need each PCE server to 
distribute information about connection with it's clients to all peers

The suggestion frees PCE server from the need to propagate it's client 
connection status to all other PCE servers.

Let me know what you think

Thanks
Aaron

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