RE: IP Traffic Engineering

[Linda Dunbar <[e-mail]>]

Robert,

Thanks for the quick reply.
Do you mean that P2 in Figure 1 can switch and swap labels carried by the IP header (for the T2 Path_A2)  based on the instruction from the controller ?
[cid:image001.png@01D57563.F92A51D0]

My question is only to check if it is possible utilizing existing features on routers.

If P2 can be upgraded to support swapping bits in IP header, then more new features can be enabled (in addition to yours).

Linda

From: Robert Raszuk <[e-mail]>
Sent: Friday, September 27, 2019 5:53 PM
To: Linda Dunbar <[e-mail]>
Cc: RTGWG <[e-mail]>; [e-mail]
Subject: Re: IP Traffic Engineering

Hi Linda,

Thank you for reading the proposal. Organizationally per recommendation from AD and chairs we will be moving this work to TEAS hence I am cc-ing that group.

As to your first question - P nodes are non participating nodes only running plain IP routing. Imagine those are ISPs between my anchor nodes - no PCE can talk to them. But this does not change the core of your question.

You are essentially asking - can I do the same using MPLS swapping + IP encap on SE nodes. Well technically you can - but the main motivation of this proposal is to minimize per packet overhead. And if you can simply do IP lookup why to throw away peeling the packet with nice bits which can contain more then needed information and get to next encapsulated here MPLS stack ?

Even if you look at processing chain of operations many more cycles in the data pipeline is needed to strip the header, process lookup on mpls label then apply new mapping then match new mapping to another encapsulation IP header, apply new IP header etc ... I do not see much rationale doing such maneuvers. I think while MPLS as service demux is great idea I would not invest too much in any solutions which relay on using MPLS as a transport.

For section 7 the answer is it depends. Some functions local to the midpoints for sure can be triggered by control plane. However some functions may be common to all packets (for example let's timestamp the packet at each TE midpoint) so it makes sense to have an architecture which allows to embed such function. On a similar note VPN demux values known on VPN ingress should be applied there and not carried in TE control plane if for nothing else then for avoiding TE control plane unnecessary grow.

Many thx for asking,
Robert.


On Sat, Sep 28, 2019 at 12:22 AM Linda Dunbar <[e-mail]<mailto:[e-mail]>> wrote:
Robert,

Interesting proposal, especially on the Active Path Probing allowing minimum path quality metrics to be specified for data plane.

Can I use MPLS over IP solution + PCE to achieve what you show in Figure 1?
e.g. for T2 Path: PCE can instruct the proper switching on P2 for the path, and instruct the PE1 for the proper MPLS label, then the PE1 encapsulate the MPLS packet in IP packet (which can traverse the plain IP network to P2); P2 does the MPLS label swapping and switching instructed by the controller, and encapsulate the MPLS packet in the new label assigned by P2 in another IP packet to PE2.

For Section 7 Network Programming, you propose adding the information about the selected function to packet. If intermediate nodes can get instruction from the controller, why not letting the controller inform the list of functions for the packets at the specific nodes instead carried by the packets?

Linda Dunbar

From: rtgwg <[e-mail]<mailto:[e-mail]>> On Behalf Of Robert Raszuk
Sent: Thursday, September 26, 2019 6:07 PM
To: RTGWG <[e-mail]<mailto:[e-mail]>>
Subject: IP Traffic Engineering

Dear RTGWG,

I just submitted a document where I present new perspective on traffic engineering for IP networks. As the scope of the new architecture and deployment target does not fit any other working group I decided to submit it to RTGWG.

Comments, opinions, contribution - very welcome !

Kind regards,
Robert.

- - -

A New Internet-Draft is available from the on-line Internet-Drafts directories.


        Title           : IP Traffic Engineering Architecture with Network Programming
        Author          : Robert Raszuk
        Filename        : draft-raszuk-rtgwg-ip-te-np-00.txt
        Pages           : 22
        Date            : 2019-09-26

Abstract:
   This document describes a control plane based IP Traffic Engineering
   Architecture where path information is kept in the control plane by
   selected nodes instead of being inserted into each packet on ingress
   of an administrative domain.  The described proposal is also fully
   compatible with the concept of network programming.

   It is positioned as a complimentary technique to native SRv6 and can
   be used when there are concerns with increased packet size due to
   depth of SID stack, possible concerns regarding exceeding MTU or more
   strict simplicity requirements typically seen in number of enterprise
   networks.  The proposed solution is applicable to both IPv4 or IPv6
   based networks.

   As an additional added value, detection of end to end path liveness
   as well as dynamic path selection based on real time path quality is
   integrated from day one in the design.


The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-raszuk-rtgwg-ip-te-np/<https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-raszuk-rtgwg-ip-te-np%2F&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C02ff3b0165bc4f7fdddd08d7439d6ae9%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637052215698214872&sdata=rVQaZc1YQFAmmrODfzEpraJToztMiI1vCu8%2B0aBnh%2BQ%3D&reserved=0>

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-raszuk-rtgwg-ip-te-np-00<https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftools.ietf.org%2Fhtml%2Fdraft-raszuk-rtgwg-ip-te-np-00&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C02ff3b0165bc4f7fdddd08d7439d6ae9%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637052215698224875&sdata=9VNG6OhnlJVQUuwz6JlfJek%2F5MDd3SAVVodLUIXagmg%3D&reserved=0>
https://datatracker.ietf.org/doc/html/draft-raszuk-rtgwg-ip-te-np-00<https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-raszuk-rtgwg-ip-te-np-00&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C02ff3b0165bc4f7fdddd08d7439d6ae9%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637052215698234871&sdata=KsxSjEST0DHGRBvV2fDIgxa5s3euuEzf7kXnkpP%2FYD0%3D&reserved=0>