Re: [Pce] Whither Stateless PCE?

[Olivier Dugeon <[e-mail]>]

Hello Robert,

Le 08/09/2016 11:38, Robert Varga a écrit :
> On 09/07/2016 05:57 PM, Ina Minei wrote:
>> I think if we replace MUST with SHOULD in the text you provided that
>> would work for the transition. Can implementors comment on the impact?
> The change in PCRpt format is incompatible with fielded installations.
>
> OpenDaylight will refuse a PCRpt consisting of (LSP, NO-PATH) and will
> raise an Mandatory Object Missing PCErr, leading to failure to perform
> initial state synchronization. The requirement has been there since
> revision 05 (at least) and has been clarified in revision 16.
Agree. But, as we face to some interoperability issues between various implementation, whatever the solution we choose, we need new release, so new version of firmware in the routers and new software for the PCE. So, I prefer to have a clear fix without any ambiguity instead of patch what wil continue to be subject to misinterpretation.

Regarding OpenDayLight, I think that the modification is not too huge:

Add NO-PATH object in 'path-definition' group in pcep-types.yang (line 1027 - 1031)

    grouping path-definition {
        uses explicit-route-object;
+      uses no-path-object;
        uses lsp-attributes;
    }

Or if you prefer

    grouping path-definition {
+        choice report-path {
+            mandatory true;
+
+        case ero {       
            uses explicit-route-object;
+        }
+
+        case no-path {
+           uses no-path-object;
+        }
        uses lsp-attributes;
    }

I also look at the Stateful07TopologySessionListener() class where the PCRpt is handle. At any moment the code check that there is a valid ERO (i.e. method buildPath() line 389 and following). I also made some tests with Juniper router with RSVP-TE tunnel setup and delegated, but without an explicit route set in the config. The Juniper router report the tunnel through a PCRpt message without ERO. Just an RRO. And this is correctly handle by OpenDayLight.

So, for me there is no much issue in OpenDayLight no manage NO-PATH Object.

Regards

Olivier
> Bye,
> Robert
>