Re: IP Traffic Engineering

[Robert Raszuk <[e-mail]>]

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]>
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]> *On Behalf Of * Robert Raszuk
> *Sent:* Thursday, September 26, 2019 6:07 PM
> *To:* RTGWG <[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%7C256e22588531436f98c208d742d63f1c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637051360284126163&sdata=4iFawd0kmgkI%2BNSfbIBWQfxfeSRyp8o6%2BFsEH5RnvtU%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%7C256e22588531436f98c208d742d63f1c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637051360284126163&sdata=pt%2FDC6LOEWdUojw7xtL18ssLslnPi9RMf7MGbr5gm7E%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%7C256e22588531436f98c208d742d63f1c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637051360284136155&sdata=yne9u0y4hiOIsDrjiuPusmEUMBg8d9ICp7HozovzXFA%3D&reserved=0>
>
>