Subject: Re: [Dyncast] Will Dyncast architecture consider a very simplified version for 5G Edge Computing?

From: Luigi IANNONE <[email-masked]>
Date: Tue, 25 May 2021 08:30:21 +0000

Hi Linda,

Sorry for taking this long, this email is long overdue.

I went over your drafts (the metrics one is now expired .... ;-) )..

>From my understanding  the 5G Edge Computing architecture is in the scope of Dyncast. There is some difference in the terminology but all in all Dyncast covers sticky services (and more).

So to answer your question: yes it is in the scope of Dyncast.

What need to be worked out is how 5G UPF and the router split the function, we need more discussion on these kind of details...

Ciao

L.

From: Dyncast [mailto:[email-masked]] On Behalf Of Linda Dunbar
Sent: Wednesday, March 31, 2021 23:31
To: [email-masked]
Subject: [Dyncast] Will Dyncast architecture consider a very simplified version for 5G Edge Computing?

YiZhou, Luigi, Dirk, and Peng,

The architecture described by draft-li-dyncast-architecture-00 is very comprehensive.

We have 4 drafts on 5G Edge Computing that describes routing protocols extensions to advertise differentiated costs to reach servers attached to different (egress) routers that have the same IP address (a.k.a. ANYCAST address).

https://datatracker.ietf.org/doc/draft-dunbar-idr-5g-edge-compute-app-meta-data/
https://datatracker.ietf.org/doc/draft-dunbar-lsr-5g-edge-compute-ospf-ext/
https://datatracker.ietf.org/doc/draft-dunbar-6man-5g-edge-compute-sticky-service/
https://datatracker.ietf.org/doc/draft-dunbar-ippm-5g-edge-compute-ip-layer-metrics/

The 5G Edge Computing drafts are based on the following architecture. Comparing with the Dyncast architecture, the egress routers of the 5G Edge computing can be mapped to the D-Node in the DYNCAST architecture. But there is no D-Node in front of "clients", i.e. the "UEs".
All the UEs have their unique addresses. Only a small number of services from UEs, usually the ultra-low latency services, need multiple servers instantiated in multiple edge DCs.  Among the multiple servers for one service, some servers can have the same IP address, some may not. It really depends on the services.
There is no D-Forwarder either. All the routers in the edge network are regular IP routers. Those routers will see multiple paths towards the packets' destination and would select the lowest cost path to forwarding the packets.

Question: Do you think the 5G Edge Computing architecture belong to the scope of DYNCAST?
If yes, can  draft-li-dyncast-architecture-00 add a section to merge the 5G Edge Computing simplified architecture?

+--+
|UE|---\+---------+                 +------------------+
+--+    |  5G     |     +--------+  |   S1: aa08::4450 |
+--+    | Site +--+-+---+        +----+                |
|UE|----|  A   |PSA1| Ra|        | R1 | S2: aa08::4460 |
+--+    |      +----+---+        +----+                |
  +---+    |         |  |           |  |   S3: aa08::4470 |
  |UE1|---/+---------+  |           |  +------------------+
  +---+                 |IP Network |       L-DN1
                     |(3GPP N6)  |
  |                  |           |  +------------------+
  | UE1              |           |  |  S1: aa08::4450  |
  | moves to         |          +----+                 |
  | Site B           |          | R3 | S2: aa08::4460  |
  v                  |          +----+                 |
                     |           |  |  S3: aa08::4470  |
                     |           |  +------------------+
                     |           |      L-DN3
+--+                 |           |
|UE|---\+---------+  |           |  +------------------+
+--+    |  5G     |  |           |  |  S1: aa08::4450  |
+--+    | Site +--+--+---+       +----+                |
|UE|----|  B   |PSA2| Rb |       | R2 | S2: aa08::4460 |
+--+    |      +--+-+----+       +----+                |
+--+    |         |  +-----------+  |  S3: aa08::4470  |
|UE|---/+---------+                 +------------------+
+--+                                     L-DN2
Figure 1: App Servers in different edge DCs

Thank you.
Linda Dunbar