1. 1 © 2001, Cisco Systems, Inc. All rights reserved. © 2004, Cisco Systems, Inc. All rights reserved. RSVP Bandwidth Reduction in TSVWG draft-polk-tsvwg-rsvp-bw-reduction-00 James M. Polk Subha Dhesikan November 10 th, 2004

2. © 2001, Cisco Systems, Inc. All rights reserved. 2 2 © 2004, Cisco Systems, Inc. All rights reserved. 2 Why is this important? RSVP sets up reservations based on many properties – one of these is the bandwidth required for an RSVP flow (newsflash!) RFC 2205 defines the means of creating the “flows” RFC 3181 defines the means of prioritizing the “flows” RFC 3175 defines the means to aggregate individual flows into a ‘super-flow’ RFC 2207 defines the means of tunneling flows in IPsec with RSVP Here’s the rub, when something needs some BW from an existing flow, the whole reservation is currently gets torn down – possibly to be left to attempt reestablishment at “some” lower BW amount This document specifies how to signal for a reduction in BW of an existing reservation of any type

3. © 2001, Cisco Systems, Inc. All rights reserved. 3 3 © 2004, Cisco Systems, Inc. All rights reserved. 3 What changed from the previous version? Changed the filename and scope of doc Broadened applicability to include individual flows and encrypted RSVP flows For Aggregates, defined the Deaggregator as the controller of which individual flows are individually reduced or cleared Cleared open issue regarding ResvTear message generation – It is not to be sent by ResvErr generating router An otherwise normal 2205 behavior

4. © 2001, Cisco Systems, Inc. All rights reserved. 4 4 © 2004, Cisco Systems, Inc. All rights reserved. 4 Open issues Do we need to address the case in which the ResvErr message is sent, but the flow is not reduced in a timely manner? – this is a general RSVP issue and not introduced because of this doc

5. © 2001, Cisco Systems, Inc. All rights reserved. 5 5 © 2004, Cisco Systems, Inc. All rights reserved. 5 Plans for Effort Ready to become a TSVWG item? – chairs?? Wait and address any new comments

6. © 2001, Cisco Systems, Inc. All rights reserved. 6 6 © 2004, Cisco Systems, Inc. All rights reserved. 6 Aggregate Example

7. © 2001, Cisco Systems, Inc. All rights reserved. 7 7 © 2004, Cisco Systems, Inc. All rights reserved. 7 Reduction Scenario using Aggregates I Aggregate A Aggregate B 5 flows 5 flows 5 flows 5 flows Single circuit Interface at capacity with the 10 flows Router 1Router 2Router 3Router 4 Router 5Router 6Router 7Router 8 Router 9Router 10 Priority of Aggregate A > Priority of Aggregate B

8. © 2001, Cisco Systems, Inc. All rights reserved. 8 8 © 2004, Cisco Systems, Inc. All rights reserved. 8 Aggregate A Aggregate B 5 flows 5 flows 5 flows 5 flows Router 1Router 2Router 3Router 4 Router 5Router 6Router 7Router 8 Router 9Router 10 Single circuit Interface at capacity with the 10 flows 6th flow signaled into Aggregate A Problem at this Interface (no capacity) Priority of Aggregate A > Priority of Aggregate B Reduction Scenario using Aggregates II

9. © 2001, Cisco Systems, Inc. All rights reserved. 9 9 © 2004, Cisco Systems, Inc. All rights reserved. 9 How can this be addressed? If the ResvErr message includes a BW amount that is still available at the router, the Aggregate can be shrunk to that amount, and not torn down This will force the Deaggregator to drop some individual flows to achieve this lower BW amount (for the existing aggregate) This increases efficiency and reduces packet loss within the Aggregate For individual flows, the downstream endpoint is the controller of the flow For RSVP enabled IPsec tunnels, the tunnel generator is the controller

10. © 2001, Cisco Systems, Inc. All rights reserved. 10 © 2001, Cisco Systems, Inc. All rights reserved. 10 © 2004, Cisco Systems, Inc. All rights reserved. 10 Aggregate A Aggregate B 5 flows 5 flows 5 flows 5 flows Router 1Router 2Router 3Router 4 Router 5Router 6Router 7Router 8 Router 9Router 10 6th flow signaled into Aggregate A Solution: Router 9 sends a Bandwidth Reduction message to Router 8 to clear an amount of bandwidth Reduction Scenario using Aggregates III

11. © 2001, Cisco Systems, Inc. All rights reserved. 11 © 2001, Cisco Systems, Inc. All rights reserved. 11 © 2004, Cisco Systems, Inc. All rights reserved. 11 Aggregate A Aggregate B 5 flows 5 flows 5 flows 4 flows Router 1Router 2Router 3Router 4 Router 5Router 6Router 7Router 8 Router 9Router 10 6th flow signaled into Aggregate A Solution: Router 9 sends a Bandwidth Reduction message to Router 8 to clear an amount of bandwidth Reduction Scenario using Aggregates IV

12. © 2001, Cisco Systems, Inc. All rights reserved. 12 © 2001, Cisco Systems, Inc. All rights reserved. 12 © 2004, Cisco Systems, Inc. All rights reserved. 12 Aggregate A Aggregate B 5 flows 4 flows 5 flows 4 flows Router 1Router 2Router 3Router 4 Router 5Router 6Router 7Router 8 Router 9Router 10 6th flow signaled into Aggregate A Solution: This clears the way for flow 6 of Aggregate A to be completed 6th flow Reduction Scenario using Aggregates V