Hi Satoru, Thank you for reviewing the changes in 3.3, rev 18 and for the detailed comments.
The text in the draft should be revised. Broad outline of revision: - EP_Transport/.../ATTACHMENT_CIRCUIT with UDP source port number/range is provisioned (before PDU session setup) for each slice (S-NSSAI) that the 3GPP UP node supports. This uses data structures in 28.541 (details in response - email below). - During PDU session setup, N2/N4 signaling carries S-NSSAI for the PDU session and is provided to the 3GPP user plane nodes. N2/N4 signaling is in 23.502, 4.3.2 and 38.413 (NGAP - N2), 29.244 (PFCP - N4). The ATTACHMENT_CIRCUIT /UDP source port number can thus be associated and used when forwarding a GTP-U packet. Detailed responses and proposed text changes are inline below and tagged [-- Response --]. Regards, John > -----Original Message----- > From: Satoru Matsushima <[email protected]> > Sent: Tuesday, April 22, 2025 9:40 AM > To: Kaippallimalil John <[email protected]> > Cc: dmm <[email protected]>; dmm-chairs <[email protected]>; Charles Eckel > (eckelcu) <[email protected]>; Lionel Morand <[email protected]> > Subject: Re: draft-ietf-dmm-tn-aware-mobility-18 > > Hi John, thank you for the update. > > As you mentioned, I reviewed section 3.3 in terms of both the prior to PDU > session establishment, and during PDU session establishment. > > In section 3.3 para 2, the draft says below: > > > 3GPP user plane nodes (gNB, UPF) are provisioned with GTP transport > > interface information parameters in [TS.28.541-3GPP] for an S-NSSAI. > > > > But I couldn't find exact IOC or attribute defined in TS28.541 to bind GTP > transport interface info parameters for an S-NSSAI. > Can you please indicate where the IOC and/or the attribute defined in > TS28.541? [-- Response 1--]: Good point - 3GPP only configures S-NSSAI in N4/N2, and does not carry the S-NSSAI in GTP-U. The text "for an S-NSSAI" should be removed. The sentence could be revised to: "The 3GPP user plane nodes (gNB, UPF) are provisioned with GTP transport interface information parameters in [TS.28.541-3GPP]. Each EP_Transport is configured with ATTACHMENT_CIRCUIT containing UDP source port number/range for each of the slices (S-NSSAI) supported by the 3GPP user plane node. The "ATTACHMENT_CIRCUIT" is an enumerated value in connectionPointId (externalEndPointRefList) attribute in EP_Transport." > > Also in section 3.3 para 3, the draft says below: > > > During PDU session setup, the 5G control plane configures parameters > > to setup the user plane for the PDU session across F1-U, N3 and N9 > > interfaces. They include the S-NSSAI and corresponding EP_Transport > > information which contains the IP address interface of the GTP-U > > destination and the connectionPointID with attachment circuit > > information. The 3GPP user plane node can now associate the > > provisioned slice and EP_transport to that signaled for the PDU > > session. > > > > I suppose that the above text implies N2, or N4 interface procedures since it > describes PDU session establishment. > But I couldn't find neither EP_Transport nor connectionPointID parameters in > both the N2 (TS38.413) and N4 (TS29.244). > So can you please indicate where those parameters are included in the N2 and > N4? [-- Response 2 --]: Agree, EP_Transport and connectionPointID are not configured per PDU session, only the S-NSSAI is. Will revise the text to reflect this: " During PDU session setup, the 5G control plane configures parameters to setup the user plane for the PDU session across F1-U, N3 and N9 interfaces. They include the S-NSSAI which allows for the previously configured EP_Transport/ATTACHMENT_CIRCUIT (with UDP source port number/range) to be used when forwarding a GTP-U packet belonging to the PDU session." > > In addition, the Fig.3 in the draft depicts EP_Transport info model which > includes some attributes of the connectionPointIDType, and the > connectionPointID. > But I couldn't find those attributes in EP_Transport IOC in TS28.541. > So can you please indicate where those attributes are defined in EP_Transport > IOC? [-- Response --]: TS28.541, section 6.3.18 : EP_Transport Attributes ( 6.3.18.2) refers to externalEndPointRefList (defined in 6.4.1). 6.4.1 (externalendPointRefList identifies a list of ConnectionPointInfo (6.3.41) -> connectionPointIdType (6.4.1) - one of which is "ATTACHMENT_CIRCUIT". I did not add these pointers to sections in the specification since the slice mapping concepts in the draft/RFC should be possible to use even as 3GPP standards evolve. > > Best regards, > --satoru > > > > > 2025/04/22 4:26、Kaippallimalil John > <[email protected]>のメール: > > > > Hi All, > > I do appreciate all the detailed reviews and comments after rev 17, and > during IETF 122 dmm session. > > The following updates have been made to address comments: > > • Comment that slice types listed in section 1 should be exemplary > > (updated in first para, section 1) > > > > • Clarify relation between 5QI/slices. Updated in section 2 (snippet below): > > “The TN PE does not consider 5QI in the DSCP or GTP-U header for mapping > the 5G slice. 3GPP QoS with 5QI and corresponding DSCP mapping can be > applied to traffic flows in PDU sessions in the slice independently.” > > > > • Comment in IETF 122: “S-NSSAI and relation to EP_Transport is not clear” > > Revised section 3 as follows. > > Split the original section 3.2 into 2 sections (3.2 and 3.3) as that > > section was > getting too long. > > Aspects of 3GPP slice configuration are now in section 3.2 and no changes to > the text there were needed. > > Text in section 3.3 is revised to describe configuration related to S-NSSAI, > EP_Transport on 3GPP nodes and IP PE, both prior to PDU session > establishment, and during PDU session establishment. > > The changes can be found in paragraphs 2 and 3 of section 3.3. > > Also, a few changes in section 5.1 to link the changes in 3.3 to the ACaaS > extension for UDP tunnel. > > > > And thank you - Charles and Lionel - for volunteering to review this new > revision. > > Links to the new revision: > > Datatracker: > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdata > > tracker.ietf.org%2Fdoc%2Fdraft-ietf-dmm-tn-aware- > mobility%2F&data=05%7 > > > C02%7Cjohn.kaippallimalil%40futurewei.com%7C9ed77f1a895f42489f1b08 > dd81 > > > aba5f0%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C63880929 > 6418346929 > > > %7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAu > MDAwMCIsI > > > lAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sd > ata=XMK > > db911JCtX%2BpF%2BqhPc7L2nfXCj99DoIAE3SFSHo1Y%3D&reserved=0 > > Diff: > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fauth > > or-tools.ietf.org%2Fiddiff%3Furl2%3Ddraft-ietf-dmm-tn-aware-mobility- > 18&data=05%7C02%7Cjohn.kaippallimalil%40futurewei.com%7C9ed77f1a8 > 95f42489f1b08dd81aba5f0%7C0fee8ff2a3b240189c753a1d5591fedc%7C1 > %7C0%7C638809296418401661%7CUnknown%7CTWFpbGZsb3d8eyJFbXB > 0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFp > bCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=qKVv9i6izqujtZF7MKe76v > aeYujCyQk0c39pFp4DQ9s%3D&reserved=0 > > Best Regards, > > John > _______________________________________________ dmm mailing list -- [email protected] To unsubscribe send an email to [email protected]
