Subject: Re: [5gangip] [E] Re: MINUTES of side meeting in Singapore

From: "Bogineni, Kalyani" <[email-masked]>
Date: Sun, 10 Dec 2017 13:36:28 +0000

David:

Response inline [KB]

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Sunday, December 10, 2017 4:49 AM
To: Bogineni, Kalyani <[email-masked]>; [email-masked]
Subject: RE: [5gangip] [E] Re: MINUTES of side meeting in Singapore

Kalyani

So just to be 100% sure here we would be considering UPF <-> UPF traffic internal to the core and not N3/N6 protocols which are already fixed by 3GPP?

[KB] yes UPF to UPF internal to the core. N6 is SGi interface which is regular IP. N3 is GTP-U from gNB to UPF

And for reference "translating" from 4G EPC to 5G C:

S1-U = N3 = GTP over UDP

S1-C = N2 = SCTP over UDP

SGi  = N6 = IP

[KB] For now that would be the basis since CT is still working on the N interfaces for 5G.

In other words, for now, gNB will be identical to current eNB except it will have support for 5GNR and/or LTE?

[KB] gNB is only 5G NR. It can talk to eNB via Xn interface. Just for reference, here are the various architecture options being

considered in 3GPP.

Looking at just the data-plane traffic and considering 3 UPFs just as an example (minimum is 1 UPF), we get to:

----- N3 (GTP) ----- UPF(1) ----- N9 ----- UPF(2) ----- N9 ----- UPF(3) ----N6

[KB] The above is for UE to Internet or application server. Another use case is UE to UE.

UE1 ----- gNB ----- N3 (GTP) ----- UPF(1) ----- N9 ----- UPF(2) ----- N3 (GTP) ----- gNB ----UE2

Use case with traffic to another UE and also to Internet

UE1 ----- gNB1 ----- N3 (GTP) ----- UPF(1) ----- N9 ----- UPF(2) ----- N9 ----- UPF(3) ----N6

                                                                    |

                                                                   N9

                                                                    |

UE2 ----- gNB2 ----- N3 (GTP) ----- UPF(2)

David

-----Original Message-----

From: 5gangip [mailto:[email-masked]] On Behalf Of Bogineni, Kalyani

Sent: 09 December 2017 21:32

To: [email-masked]<mailto:[email-masked]>

Cc: Bogineni, Kalyani <[email-masked]<mailto:[email-masked]>>

Subject: Re: [5gangip] [E] Re: MINUTES of side meeting in Singapore

All:

3GPP CT4 has agreed to study possible candidates for user plane protocol for N9 (UPF - UPF) interface based on stage 2 requirements from TS 23.501 which specifies system architecture for the 5G system. TS 23.502 specifies procedures for the 5G system.

You can refer to TS 23.401 and TS 23.402 to  understand how IP session management and mobility management work in LTE and with non-3GPP accesses.

Some references for GTP:

TS 29.281: Protocol details of GTPv1-U

TS 29.274: Protocol details of GTPv2-C

TS 29.244: Interface between control and user plane of EPC nodes

Kalyani Bogineni

Verizon