[spring] How Encoded SID should be placed in SL (SRv6-mobile-uplane)

["Kentaro Ebisawa" <[e-mail]>]

Hi,

I have a few questions about how Encoded SID should be placed in Segment 
List and IPv6 Dst Address in Mobile User-Plane use case.

# Refering to draft-matsushima-spring-dmm-srv6-mobile-uplane-01.
# I tried to check Slides from IETF 99 but link seems to be missing.
# 
https://datatracker.ietf.org/doc/slides-99-dmm-srv6-for-mobile-user-plane/


Q1) Up Link packet (existing network to SRv6)

 > outer IPv4 and tunnel header. And then the endpoint does T.Insert
 > process with the SID which consists of the allocated domain-wise SID
 > prefix, source and destination addresses, and tunnel identifier as
 > described in Figure 3. Then the endpoint send out the packet to the
 > SRv6 network along with its routing policy.

How would IPv6 src/dst addr and Segment List look like for this Up Link 
packet? (existing network to SRv6)
My understanding is usually source address of the T.Insert node is not 
included in Segment List.
But from above description, it looks like you intend to require Encoded 
SID (Fig 3) to be included in the Segment List of UL packet.

For example, is below packet structure what you intended in case you 
have n segments to traverse in SRv6 nework?

IPv6 Src: Encoded SID or T.Insert node ??
IPv6 Dst: SL[n]
Segment Left = n
SL[0] = Segment 0
SL[n] = Segment n
SL[n+1] = Encoded SID


Q2) Down Link packet (SRv6 to existing network)

 > When the endpoint receives packet and the active segment of the
 > packet indicates the SID, the endpoint pop the SRH of the SID, and

On the other hand, are there any reason that description in page 7 does 
not mandate m to be zero while requiring to pop the SRH?
My understanding of DL packet (SRv6 to existing network) is as below.

IPv6 Src: Origin Host
IPv6 Dst: SL[n]
Segment Left = n
SL[m] = Encoded SID
SL[m+1] = Segment m+1
SL[n] = Segment n


Regards,
--
Ponto Networks, Inc.
Kentaro Ebisawa <[e-mail]>