Re: [Roll] projected route or not?

Rahul Arvind Jadhav <rahul.jadhav@huawei.com> Mon, 27 May 2019 01:19 UTC

From: Rahul Arvind Jadhav <rahul.jadhav@huawei.com>
To: Routing Over Low power and Lossy networks <roll@ietf.org>
Thread-Topic: projected route or not?
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Date: Mon, 27 May 2019 01:19:32 +0000
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Subject: Re: [Roll] projected route or not?
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Hi Pascal,

Just for my understanding, the points mentioned below are on how to handle the projected routes failure during installation using PDAO and handle the partially projected route cleanup and notification to the root. As I understand, the partial cleanup currently is left to the root (possibly by using PDAO(lifetime=0)) once the root is notified of the failure.
Post-installation, the projected path may fail and also needs cleanup and notification to root. Is this also part of this discussion?

The way I see it, there are overall 4 scenarios and 4 requirements for projected route cleanup:

Scenarios:

1.       Network is in Storing MOP, and the PDAO could be storing or non-storing

2.       Network is in non-storing MOP, and PDAO could be storing or non-storing

Requirements for projected route cleanup:

1.       During Installation of routes

a.       Notification to the root

b.      Cleanup of partially installed routes. (Root cleans up once notified of the failure?)

2.       Post-installation failure of routes

a.       Notification to the root

b.      Cleanup of projected routes

Network base MOP

PDAO type

During installation

Post Installation

Notification

Partial-PDAO Cleanup

Notification

Cleanup

Storing

Storing-PDAO









Non-storing PDAO









Non-storing

Storing-PDAO









Non-storing PDAO










I am not proposing my views on the solution here, but just trying to layout the full picture for error handling and trying to check if the understanding is ok.

Regards,
Rahul

From: Roll [mailto:roll-bounces@ietf.org] On Behalf Of Pascal Thubert (pthubert)
Sent: 23 May 2019 16:21
To: Routing Over Low power and Lossy networks <roll@ietf.org>
Cc: Li Zhao (liz3) <liz3@cisco.com>
Subject: [Roll] projected route or not?

Dear all

In case of an error in a P-route, the node that discovers an error notifies the root with a new ICMP "Error in Projected Route".
In the case of a storing mode PDAO, this is determined by the type of the route with the highest precedence in the routing able.. But for non-storing, it is hard to fathom.

Possible solutions:
-          it could be  implicit for any source route that does not originate from the root. But then, this may create a confusion in a future specification.
-          update RFC 6550, RFC 6553 and RFC 8138 to add a flag in the RPI indicating projected route
-          update RFC 6550, RFC 6554 and RFC 8138 to add a flag in the SRH indicating projected route
-          encode that information implicitely in the instance ID by telling the nodes that a range of instance IDs are reserved for P DAO
-          do not use "Error in Projected Route" to the root for non-storing P DAO. RPL has an ICMPv6 "error in Source Routing Header" message that is sent to the source of the packet. But that means that the packet goes to the source which then can notify the root. This is quite inefficient when the network is non storing.
-          ?

What do you think?

Pascal

[Roll] projected route or not? Pascal Thubert (pthubert)
Re: [Roll] projected route or not? Rahul Arvind Jadhav
Re: [Roll] projected route or not? Pascal Thubert (pthubert)