65th IETF Meeting, Dallas, TX, USA
Mobopts Research Group Meeting
March 21, 2006, 13:00-15:00h
Metropolitan Ballroom, Hilton Anatole

Minutes taken by Christian Vogt, chvogt@tm.uka.de



MEETING AGENDA

1. Introduction, document status, new IRTF RFC process
   Rajeev, 15 minutes.

2. Link Characteristics Information conveyance
   Jouni Korhonen, 20 minutes.

3. Network-initiated handovers, Telemaco Melia, 20 minutes.
   draft-melia-mobopts-niho-ps-01.txt

4. Early Binding Updates for Mobile IPv6 and Credit-Based Authorization
   Christian Vogt, 20 minutes.
   draft-vogt-mobopts-simple-ebu-00.txt
   draft-vogt-mobopts-simple-cba-00.txt

5. MIP6 Location Privacy
   Qiu Ying, 30 minutes.
   draft-irtf-mobopts-location-privacy-solutions-00.txt

6. Context Transfer of Mobile IPv6 Multicast Listeners
   Hugo Santos, 15 minutes.
   draft-santos-mobopts-mcast-ctx-transfer-00.txt



MEETING MINUTES

1. Introduction, document status, new IRTF RFC process, Rajeev, 15 minutes.

- See slides.



2. Link Characteristics Information conveyance
   Jouni Korhonen, 20  minutes.

Presentation:

- Preliminary simulation results, TCP-based
- LCI delivered along with MIP6 signaling
- TCP Quick Adjust to rapidly adapt to new link characteristics (sets cwnd)
- Simulation scenario:  MN moves btw. WLAN and GPRS, FTP from CN to MN
- Conclusion:  Link characteristics most important for properties of entire path
- Issue:  How to obtain characteristics of new link?  IEEE 802.21?

Discussion:

Rajeev:  Wouldn't it make sense to get link information ahead of L2 handoff?
Jouni:  This is where 802.21 gets into.
Rajeev:  Piggybacking link information onto MIP6 signaling makes sense because MIP6 has handoff information earlier than transport layer.

Sally Floyd:  Quick Start should only be used if the router is (absolutely) sure that it has sufficient bandwidth and other packets won't be affected.
Jouni:  Yes, although Quick Start was just one example.

Pasi:  Not only the bandwidth on the last hop, but on the complete path needs to be taken into account.
Rajeev:  The assumption is that the last hop is the bottleneck and the rest of the path does not change much.



3. Network-initiated handovers
   Telemaco Melia, 20 minutes
   draft-melia-mobopts-niho-ps-01.txt

- Draft considers aspects of 3GPP and 802.21:  network triggers handoff, 802.21 events support the network for decision making
- New terminology:  PDP, PEP
- Simulation results currently being validated; will be available soon

Discussion:

Christian:  There seems to be a niche (between MIP6, HMIP6, NETLMM, etc.) where this work would fit quite nicely.

James:  This could be used for 802.11 networks; 802.16 already have that functionality as part of L2.

Rajeev:  Section on inter-domain handoffs, operator interaction.

Hui:  Different documents for security threats, architecture, protocol.

Eric:  You are bringing back some intelligence back from the MN to the network.

Frank:  Optimal location of decisision function is interesting; somewhere between basestation or gateway.
Telemaco:  Depends on your deployment.
Frank:  Inter-technology handoffs can have very different handoff delays.



4. Early Binding Updates for Mobile IPv6 and Credit-Based Authorization
   Christian Vogt, 20 minutes
   draft-vogt-mobopts-simple-ebu-00.txt
   draft-vogt-mobopts-simple-cba-00.txt

- Why do we need enhancement?
- Constituent enhancements:  proactivity, concurrency, higher degree of parallelism
- Reduction of handoff delays from 4 RTT to 1 RTT for reactive handoffs, 0~1 RTT for proactive handoffs
- Concurrent CoA test == use CoA while it's verified ==> Credit-Based Authorization
- Experimental testbed
- Measurements for IP telephony
- Measurement for TCP file transfers

Discussion:

Greg Daley:  We experimented with EBU.  Approach is solid and it works.



5. MIP6 Location Privacy
   Qiu Ying, 30 minutes.
   draft-irtf-mobopts-location-privacy-solutions-00.txt

Presentation:

- Analysis of location privacy
- Suggested approach based on Pseudo HoA
- Brief idea for location privacy with standard RR signaling:  CN and MN create shared key

Discussion:

Kilian:  This approach uses bidirectional tunnling, which is really simple and there are more efficient mechanisms in Mobile IPv6 that can be used and should benefit from location privacy.
Rajeev:  This is about mechanisms that already exist in RFC3775, whereas Kilian's approach uses external mechanisms.
Kilian:  Yes, but even standard Mobile IPv6 has Route Optimization, which is more efficient than bidirectional tunneling.

Christian:  It would be good to have a section in the draft that demarcates this approach from other approaches in location privacy.



6. Context Transfer of Mobile IPv6 Multicast Listeners
   Hugo Santos, 15 minutes.
   draft-santos-mobopts-mcast-ctx-transfer-00.txt

James:  There is an appendix in the CxTP RFC that talks about MLD context transfer.
Hugo:  Yes, but the CxTP RFC only supports MLDv1, this one is for MLDv2.  MLDv2 provides source-specific mulitcast.  MLDv1 does not.  Also, this approach is more simple.