1. (Flow Related) DLEP Extensions
Lou Berger
David Wiggins
Bow-Nan Cheng

2. Four Drafts DLEP Control Plane Based Pause Extension
draft-cheng-manet-dlep-pause-extension-00
a simple control plane based flow control mechanism
DLEP DiffServ Aware Credit Windowing Extension
draft-cheng-manet-dlep-da-credit-extension-00
a DiffServ aware credit-windowing scheme
DLEP Latency Range Extension
draft-cheng-manet-dlep-latency-extension-00
reports latency that may be experienced on a link
DLEP Multi-Hop Forwarding Extension
draft-cheng-manet-dlep-multi-hop-extension-00
reporting and control of multi-hop forwarding
97th IETF

3. Control Plane Based Pause Extension
draft-cheng-manet-dlep-pause-extension-00
A simple control plane based flow control mechanism
Modem can send DLEP messages to pause and restart traffic
Modem indicates that traffic is to be suppressed
Device wide (Per session, using Session Update messages)
Per destination (Uses Destination Update messages)
May be DSCP specific
Pause/resume can identify a group of DSCPs (or all)
DSCPs are grouped into logical queues
Expected to have narrow applicability
Where a simple control plane “xon/xoff” capability is good enough
97th IETF

4. Pause Extension Mechanisms
1 new Extension Type
Control Plane Pause
3 new Data Item Values
Queue Parameters Pause / Restart
| Data Item Type | Length |
| Num Queues | Scale | Reserved |
|Num DSCPs Q0(0)| Queue Size Q |
| Num DSCPs Q1 | Queue Size Q |
| Num DSCPs Q2 | Queue Size Q |
: :
| Num DSCPs Qn | Queue Size Qn |
| DS Field Q1 | DS Field Q1 | DS Field Q1 | DS Field Q2 |
: | DS Field Qn |
| Data Item Type | Length |
| Queue Index | :
: | Queue Index |
Queue Size is Informational
Open issue:
Encoding of {Queue, DSCP list} seems “complex”
Is there simpler encoding?
97th IETF

5. DiffServ Aware Credit Windowing Extension
draft-cheng-manet-dlep-da-credit-extension-00
A DiffServ aware credit-windowing scheme
More sophisticated flow control, for a wide range of applications
For modems that have DSCP related queuing
Modem send credit grants and credit increments to a router
Per destination, and per DSCP group (queue)
Grants set/reset a credit window
Router can request credits
Routes advertise their credit window status
So modems can adapt/reset as need
Credits are in bytes and include MAC headers
97th IETF

6. Credit Windowing Mechanisms
1 new Extension Type – DiffServ Aware Credit Windowing
2 new Messages
Credit Control and Credit Control Response
Modem  Router – credit increment
Router  Modem – status response – credit request
4 new Data Items
Queue parameters – Same as pause*
DA Credit Grant
Sets credit windows in Destination Up/Update/Announce Response messages
Increments windows in Credit Control messages
DA Credit Window Status
DA Credit Request
97th IETF

7. Latency Range Extension
draft-cheng-manet-dlep-latency-extension-00
Reports latency range that may be experienced on a link
Builds on Latency Data Item, provides Min and Max Values
1 new Extension Type – Latency Range
1 new Date Item – Latency Range
| Data Item Type | Length |
| Maximum Latency :
: Maximum Latency |
| Minimum Latency :
: Minimum Latency |
97th IETF

8. Multi-Hop Forwarding Extension
draft-cheng-manet-dlep-multi-hop-extension-00
Supports reporting and control of multi-hop forwarding
Some modem technologies support connectivity to destinations via multi-hop forwarding at the mac layer
Modems inform routers when multi-hop forwarding is being used
Modems indicate hop count, and ability to change hops
Routers MAY use hops in forwarding/routing decisions
Routers request modems to change multi-hop forwarding behavior
Per device, can request to suppress multi-hop forwarding
Per destination, can request or terminate direct connections
Can request to restore default behavior
Requests can succeed, fail or be rejected
Results are reported via hop count
97th IETF

9. Next Steps Gauge WG interest Solicit feedback Fix typos
Aiming towards WG drafts
Is there interest in all/some?
Solicit feedback
Questions / Comments???
Please read and send questions / comments to list
Fix typos
Publish open source implementation
Expected under
DLEP, these extensions, wireshark dissector
97th IETF