1. Bala’zs, Norm, Jouni DetNet WG London, 23rd March, 2018
DetNet Discussions
Bala’zs, Norm, Jouni
DetNet WG
London, 23rd March, 2018
3/23/2018

2. DetNet Service Networking characteristicsX
Service types
L2/TSN IP
DetNet Encapsulation:
MPLS X L2 L2 L2 L2 X X IP L3 L3 IP

3. DetNet functions & nodes (as per draft-ietf-detnet-architecture)
Congestion protection (Queuing) need: flow identification
Explicit routes (TE) need: flow identification
Service protection (PREF, IOD) need: flow id + sequence number
Note: These three techniques can be applied independently …
Note: Svc Proxy = DN-Inter-Working Function (DN-IWF)
TSN Edge Transit Relay DetNet
End System Node Node Node End System
| Appl. |<---:Svc Proxy:-- End to End Service >| Appl. |
| TSN | |TSN| |Svc|<-- DetNet flow ---: Service :-->| Service |
|Transport| |Trp| |Trp| |Transport| |Trp| |Trp| |Transport|
: Link : / , \ : Link : / , \
[ Sub ] [ Sub ]-+
[Network] [Network]
`-----' `-----'
DetNet nodes
Edge node req.functions: 1, 2, 3
Relay node req.functions: 1, 2, 3
Transit node req.functions: 1, 2
2/14/2018

4. Agenda MPLS DetNet IPv{4|6} DetNet Edge behaviors Other topics
3/23/2018

5. MPLS DetNet
3/23/2018

6. MPLS encapsulation with PREF
*Note: end-system without IP stack
MUST include d-CW (for PREF)
DetNet MPLS-based encapsulation
| |
| DetNet Flow |
| Payload Packet |
| (e.g., IP, Eth) |
<--\
| DetNet Control Word | |
> DetNet data plane
| S-Label | | MPLS encapsulation
<--/
| T-Label(s) |
| Data-Link |
| Physical |
+----+
| | X X IP X IP L2 L2
MPLS
MPLS
MPLS
DetNet IP over MPLS
DetNet Ethernet L2VPN
DetNet MPLS examples
DetNet control word (d-CW) provides sequencing number for packet replication and duplicate elimination purposes.
DetNet S-Label that identifies a DetNet flow within a DetNet Edge or a Relay node.
3/23/2018

7. MPLS encapsulation without PREF
Should we include d-CW (no PREF) ?
DetNet MPLS-based encapsulation
| |
| DetNet Flow |
| Payload Packet |
| (e.g., IP, Eth) |
<--\
| DetNet Control Word | |
> DetNet data plane
| S-Label | | MPLS encapsulation
<--/
| T-Label(s) |
| Data-Link |
| Physical | X
+----+
| | X X IP IP L2 L2
MPLS
MPLS
MPLS
DetNet IP over MPLS
DetNet Ethernet L2VPN
DetNet control word (d-CW) provides sequencing number for packet replication and duplicate elimination purposes.
DetNet S-Label that identifies a DetNet flow within a DetNet Edge or a Relay node.
3/23/2018

8. IPv{4|6} DetNet
3/23/2018

9. DetNet IP Simplified IP
Using appl. native encap. format, limited or no DetNet encap. headers
DetNet Encapsulation: unmodified IP stack
6-tuple (5+DSCP) to identify flows (may include wildcards …)
No sequence number included
No end-to-end PREF
______
_____ / \__
____ / \__/ \___ ______
__/ +====== == \
|src |__/ Seg1 ) | | \ Seg3 \____| dst|
\_______ \ Segment | \+_____/
\======+__ _+===/
\ __ __/
\_______/ \___/
Simplified IP scenario
DetNet Functions Coverage
IP packet 6-tuple is matched and mapped to DetNet capable link/sub network
3/23/2018

10. Simplified IP encapsulation
| |
| Payload Packet |
|IP Transport header e.g., UDP |
| IP Header |
| Data-Link |
| Physical |
6-tuple = {src-IP, dst-IP, Proto, src-Port, dst-Port, DSCP} any field can be wildcarded/masked X
src/dst IP
IP PSN scenario
Flow identification per hop
Standard router IP header processing (only TTL/Checksum modified)
Implementing DetNet functions with simplified IP
Congestion protection (Queuing) need: flow-identification
6-tuple match based queue selection, latency control
Explicit routes (TE) need: flow-id
Paralels Policy Based Routing on 6-tuple match
Service protection (PREF, IOD) need: flow-id + Seq#
Not supported
Encapsulation of a native IPvX (6-tuple)
3/23/2018

11. Native IP encapsulation current draft text is out of date
| |
| DetNet Flow |
| Payload |
| Optional DetNet DstOpt Hdr (1) |
| Inner IPv6 header |
| (with set Flow label) (1) |
<--+
| Optional Routing header | | |
| Optional DetNet DstOpt Hdr (2) | Added/removed by
| DetNet Edge node
| Outer IPv6 header | |
| (with set Flow label) (2) | |
DetNet IP Examples X X IP X
src/dst L2 L2 IP IP IP IP L2 L2 L2
ingress/egress (PE nodes of DetNet domain)
Encapsulation of a DetNet-flow IPv6 packet at the DetNet Edge node
3/23/2018

12. Edge Behaviors
3/23/2018

13. DetNet functions & nodes (as per draft-ietf-detnet-architecture)
Scenarios
- L2VPN/TSN over MPLS
- IP over MPLS
DetNet functions
Congestion protection (Queuing) need: flow-ID
Explicit routes (TE) need: flow-ID
Service protection (PREF, IOD) need: flow-ID + Seq#
Note: These three techniques can be applied independently …
Note: Svc Proxy = DN-Inter-Working Function (DN-IWF)
TSN Edge Transit Relay DetNet
End System Node Node Node End System
| Appl. |<---:Svc Proxy:-- End to End Service >| Appl. |
| TSN | |TSN| |Svc|<-- DetNet flow ---: Service :-->| Service |
|Transport| |Trp| |Trp| |Transport| |Trp| |Trp| |Transport|
: Link : / , \ : Link : / , \
[ Sub ] [ Sub ]-+
[Network] [Network]
`-----' `-----'
DetNet nodes
Edge node req.functions: 1, 2, 3
Relay node req.functions: 1, 2, 3
Transit node req.functions: 1, 2
2/14/2018

14. Edge node behaviors Relationship to classic VPN capabilities
End-systems may have both regular and DetNet traffic
Usually there is a DN related “classic VPN” service
DetNet traffic and regular traffic use a common UNI
same Link or Subnet
DN flows are “directed” to/from DN-PW
Upstream:
select DN-PW, encapsulate and execute DN functions (e.g., PR)
Downstream:
Execute DN functions (e.g., EF) and remove DN-PW encap
send to AC/Subnet (AC: may need modify L2 header e.g., VLAN translation) (Subnet: may need interaction with node local functions, e.g., ARP)
3/23/2018

15. Discussion items Eth/TSN over MPLS
Definition of Eth/TSN over MPLS
Mapping of TSN and non-TSN flows to DetNet encap
Number of d-CWs?
Number of S-labels?
T-label per TSN flow or per aggregate: both allowed
PREF and no-PREF cases
| |
| DetNet Flow |
| Payload Packet |
| (i.e., Eth) |
| DetNet Control Word |
| S-Label |
| T-Label(s) |
| Data-Link |
| Physical |
| |
| DetNet Flow |
| Payload Packet |
| (i.e., Eth) |
| Data-Link |
| Physical |
Edge node
3/23/2018

16. Discussion items IP over MPLS
Definition of IP over MPLS
Mapping of IP flows to MPLS LSPs
IP over native MPLS or IP over L3VPN or both?
PREF and no-PREF cases
TSN/DetNet Inter-Working Function for further study
| |
| DetNet Flow |
| Payload Packet |
| (i.e., IP) |
| DetNet Control Word |
| S-Label |
| T-Label(s) |
| Data-Link |
| Physical |
| |
| Payload Packet |
|IP Transport header e.g., UDP |
| IP Header |
| Data-Link |
| Physical |
Edge node
3/23/2018

17. Other topics
3/23/2018

18. Other topics Each requires more work, please contribute (text or drafts)
IP host: DetNet flow to TSN flow mapping
Queuing
What is the depth we need to go here? Is pointing at other specifications and stating obvious factual requirements enough?
Aggregates
There’s existing text pointing at H-LSP and DSCP based aggregation approach directions.. Is this fine?
OAM
Would this actually need a separate document/work?
TSN host to DetNet host interconnection
Transport protocol impact (Transport = TSV area)
Should not be in our scope at the moment
3/23/2018

19. Thanks …
3/23/2018

20. Backup Service & Encapsulations
3/23/2018

21. DetNet Service Encapsulation within the DetNet domain – L2 service
Option 1: PWE3
DetNet Service Encapsulation within the DetNet domain – L2 service
L2 service (tunneling for L2)
Hosts are in same BC domain
Forwarding based on L2 address (i.e. ”dst-L2”)
MUST keep L2 header during transport
Tunnel Encapsulation: add new IP/MPLS header
DetNet Encapsulated X X X X IP IP
L3 host
src/dst L2 L2 L2 L2
L2 host IP
MPLS IP
MPLS X L2 L2 L2 L2 X IP
Host-part L2 L2
ingress/egress (PE nodes of DetNet domain)
DetNet-part IP
MPLS L2 L2
L2 remains
3/23/2018
PSN encap added (DetNet specific)

22. ingress/egress (PE nodes of DetNet domain)
Option 1: PWE3
DetNet Service Encapsulation within the DetNet domain – Routing service (MPLS)
Routing service (adding an MPLS tunnel)
Hosts are in different BC domain
L3 hosts only
Forwarding based on L3 address (i.e. ”dst-L3”)
Tunnel Encapsulation: add new MPLS header
DetNet Encapsulated X
src/dst
L3 host IP
MPLS X
ingress/egress (PE nodes of DetNet domain) L2 IP
Host-part L2
MPLS L2
DetNet-part
L2 stripped
3/23/2018
MPLS PSN encap added (DetNet specific)

23. Option 1: PWE3
DetNet Service Encapsulation within the DetNet domain – Routing service (IP PSN)
Routing service
Hosts are in different BC domain
Forwarding based on L3 address (i.e. ”dst-L3”)
Host-part IP contains source/destination
Tunnel Encapsulation: add new IP header
DetNet-part IP contains ingress/egress
DetNet Encapsulated X
src/dst
L3 host IP IP X
ingress/egress (DetNet domain) L2 IP
Host-part L2 IP L2
DetNet-part
L2 stripped
3/23/2018
3/23/2018
IP PSN encap added (DetNet specific)

24. DetNet Service Simplified IP – Routing service (IP PSN)
Option 2: Simplified IP
DetNet Service Simplified IP – Routing service (IP PSN)
Routing service
DetNet Encapsulation (simplified): IP header
6-tuple (5+DSCP) to identify flows
No Seq# included
Impact on network design
DetNet functions provided per network segment
May require e.g., PBR
Encapsulated
L3 host X X IP IP
src/dst + IP
Host-part L2 L2 L2
DetNet-part
L2 stripped
3/23/2018
IP encap NOT modified=