March 2010 Future TRILL Work 1

Future TRILL and TRILL Related Work

Donald Eastlake 3rd

+1-508-333-2270

d3e3e3@gmail.com

March 2010 Future TRILL Work 2

Future TRILL Work

• Potential Future TRILL Work/Documents:1. 802.1 Features

– Data Center Bridging– Priority-Based Flow Control (802.1Qbb)– Enhanced Transmission Selection (802.1Qaz)– Congestion Notification (802.1Qau)

– Provider RBridges (802.1ad, 802.1ah)

2. OAM – BFD, etc.

March 2010 Future TRILL Work 3

Questions on These Work Items

• Is the item important/high-value?

• Is the item urgent/time-sensitive?

• Who would like to work on it?

Important & Urgent

Important & Distant

Unimportant & Urgent

Unimportant & Distant

Data Center Bridging

• Three standards being specified in 802.1 to allocate bandwidth and eliminate frame loss due to queue overflow.– 802.1Qbb – per priority PAUSE

• 802.3bd – new PAUSE frame format

– 802.1Qaz – allocation of link bandwidth to traffic classes

– 802.1Qau – Congestion Notification. Facilities to limit flows at their originating end station

March 2010 Future TRILL Work 4

March 2010 Future TRILL Work 5

Data Center Bridging (cont.)

• Priority-Based Flow Control (802.1Qbb, 802.3bd)– An amendment to 802.1Q that provides the

802.3 PAUSE facility separately for different frame priorities plus an amendment to 802.3 specifying a control frame to control this PAUSE facility.

– Current in 802.1 WG Ballot recirculation.– Can be implemented in RBridge ports below

TRILL so no changes in TRILL required.

March 2010 Future TRILL Work 6

Data Center Bridging (cont.)

• Enhanced Transmission Selection (802.1Qaz)– Permits separately specifying limits for

different traffic class queues, distinguished by priority, to enforce bandwidth quotas and the like.

– Currently at Draft 1.2 in IEEE 802.1.– Can be implemented in RBridge ports below

TRILL so no changes in TRILL required.

March 2010 Future TRILL Work 7

Data Center Bridging (cont.)

• Congestion Notification (802.1Qau)– Layer 2 method to rate limit, at end stations, flows

causing congestion.• In IEEE Sponsor Ballot re-circulation.

– Some changes to RBridges beyond those required in 802.1 Bridges would be required to support 802.1Qau.

• For example, a congestion control message in response to a TRILL data frame should get back to the true origin station, not just the ingress or previous hop RBridge.

March 2010 Future TRILL Work 8

Provider RBridges• IEEE 802.1ad-2005, “Provider Bridges”, and

IEEE 802.1ah-2008, “Provider Backbone Bridges”, are completed amendments to 802.1Q to support transparent carrier Ethernet service.– Provider Bridges (Q-in-Q) use outer S-Tags– Provider Backbone Bridges (MAC-in-MAC)

• It should be straight forward to specify Provider RBridges and/or the equivalent of Provider Backbone RBridges.

March 2010 Future TRILL Work 9

OAM: Operations, Administration, and Management

• The link state database provides significant information about the entire campus to each RBridge.

• IEEE 802.1AB-2009, “Station and Media Access Control Connectivity Discovery”, provides a protocol to learn about peers.

• There should probably be a “BFD for TRILL” document.

• There should probably be some ICMP / 802.1ag like facility to implement traceroute, report errors, etc.