Re: [DMM] Presentation of https://datatracker.ietf.org/doc/draft-zzhang-bess-ipvpn-payload-only/

Hi Uma,

Indeed, the two drafts use GTP-U as an example use case but the mechanism can be used for general use cases and it is already stated as such.

If transit routers use UDP ports for ECMP hashing, I assume they'd expect full IP header before the UDP header. Therefore, the entire idea is out. Supposedly, MPLS has its own entropy label mechanism for transit routers to do hashing (vs. relying on deep packet inspection of 5-tuple), and that would be used in this case.

I will look into tn-aware-mobility draft.

Thanks.
Jeffrey

Juniper Business Use Only
From: Uma Chunduri <umac.ietf@gmail.com>
Sent: Saturday, November 5, 2022 6:39 AM
To: Jeffrey (Zhaohui) Zhang <zzhang@juniper.net>
Cc: dmm@ietf.org
Subject: Re: [DMM] Presentation of https://datatracker.ietf.org/doc/draft-zzhang-bess-ipvpn-payload-only/

[External Email. Be cautious of content]

"For example, PE1 can advertise a label for a (source, destination,

   IP/UDP payload type) tuple with the local semantics being that

   incoming traffic will be encapsulated in an IP or IP+UDP header and

   then routed out.  When PE2 receives IP or IP+UDP traffic from the

   UPF, if there is a label for the corresponding (source, destination,

   IP/UDP payload type) tuple, it removes the IP or IP/UDP headers and

   simply transport the remaining payload.  In this 5G scenario, it is

   still GTP - just that the IP/UDP headers are not present between PE1

   and PE2.
"

Very useful.

And this doesn't have to be tied to GTP overlays.  I would recommend generalizing this (just keep the overlay header intact) - though you can point to GTP as an example.
UDP might be needed for load balancing the traffic in the transport network. So better to keep this intact.
UDP Src port (is one way) to encode the slicing information as specified in https://datatracker.ietf.org/doc/html/draft-ietf-dmm-tn-aware-mobility<https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/html/draft-ietf-dmm-tn-aware-mobility__;!!NEt6yMaO-gk!CSwhjBTAYMIQ02dHF2im54429BYJPJxi2WL3ZBD83TW8BIsfRK4aPURuJ_AjjDNsCu_kXskYlnYM61KIYt0$>

Thx!
--
Uma C.

On Thu, Jul 28, 2022 at 6:08 PM Jeffrey (Zhaohui) Zhang <zzhang=40juniper.net@dmarc.ietf.org<mailto:40juniper.net@dmarc.ietf.org>> wrote:
Hi,

Due to a glitch the slides for the above draft were not available so it was not presented as planned in the DMM session in IETF114.
However, it was presented in the BESS session and the following are the video recording and slides:

https://youtu.be/V2r68JhrQag?t=660<https://urldefense.com/v3/__https:/youtu.be/V2r68JhrQag?t=660__;!!NEt6yMaO-gk!CSwhjBTAYMIQ02dHF2im54429BYJPJxi2WL3ZBD83TW8BIsfRK4aPURuJ_AjjDNsCu_kXskYlnYMcrOZrpg$>
https://datatracker.ietf.org/meeting/114/materials/slides-114-bess-draft-zzhang-bess-ipvpn-payload-only-00<https://urldefense.com/v3/__https:/datatracker.ietf.org/meeting/114/materials/slides-114-bess-draft-zzhang-bess-ipvpn-payload-only-00__;!!NEt6yMaO-gk!CSwhjBTAYMIQ02dHF2im54429BYJPJxi2WL3ZBD83TW8BIsfRK4aPURuJ_AjjDNsCu_kXskYlnYMzQopaUM$>

The direct use case that triggered the draft is GTP-U transportation, so I hope it is of interest to this group. Appreciate your comments.

Thanks.
Jeffrey

Juniper Business Use Only

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