Handoff Delay Analysis and Measurement for SIP based mobility in IPv6

1. Handoff Delay Analysis and Measurement for SIP based mobility in IPv6 Nobuyasu Nakajima, Ashutosh Dutta, Subir Das and Henning Schulzrinne

2. Outline • Introduction • Terminal Mobility Using SIP • Handoff Delay in Mid-call SIP Mobility • DAD • Router Selection • Testbed for Mobile Multimedia Communication Using IPv6 • Implementation of SIP Terminal Mobility • Handoff Delay Measurement • Conclusion

3. Introduction(1/2) • Why IPv6? • The Limitation of IPv4 address space • Network Address Translation ( NAT ) is used to circumvent the address space problem, but it fail to provide the global routability • IPv6 is designed to solve the problem

4. Introduction(2/2) • IPv6 performance issues for real-time communication • Emphasis on handoff delay due to DAD and router selection while visiting a new network and using SIP for mobility

5. Terminal Mobility Using SIP(1/3) • SIP basic procedure

6. Terminal Mobility Using SIP(2/3) • SIP terminal mobility ： pre-call

7. Terminal Mobility Using SIP(3/3) • SIP terminal mobility ： mid-call

8. Handoff Delay in Mid-call SIP Mobility(1/2) • Components of handoff delay in mid-call SIP mobility

9. Handoff Delay in Mid-call SIP Mobility(2/2) • D：total handoff delay • D1：switch lower layer medium to access network • D2：detect a new router and a new link • D3：recovery of communication with a CN after detecting a new link • DAD • Router Selection

10. Duplicate Address Detection(DAD) • DAD is to confirm the uniqueness of the IPv6 address on the link • Send a Neighbor Solicitation on the local link • During the DAD process, this address (tentative address) cannot send and receive packets • Additional delay in sending a re-INVITE • Average delay caused by DAD is 1500ms

11. Reuter Selection(1/2) • Routing Table Update • Incorporate the movement detection part of MIPL MIPv6 in our implementation as Aggressive Router Selection module • Has its own router list and is updated independently • Forcibly updates routing table after receiving router advertisement from a new access router, and delete all routers without the same prefix

12. Reuter Selection(2/2) • Neighbor Unreachability Detection (UDN)

13. Testbed for Mobile Multimedia Communication Using IPv6

14. Implementation of SIP Terminal Mobility • MN’s SIP UA is modified to send re-INVITE with new IP address information to CN • SIP UA is modified to pass the new IP address information of MN to voice communication tool • In order to keep the delay small • Modify the Linux kernel • Skip the DAD process • Select the new router through Aggressive Router Selection

15. Handoff Delay Measurement(1/3) • Handoff flow of SIP mobility in IPv6

16. Handoff Delay Measurement(2/3) • a) SIP mobility without kernel modification • b) SIP mobility with kernel modification • Handoff delay of signaling

17. Handoff Delay Measurement(3/3) • Handoff delay of media UDP packet

18. Conclusion • Modify the Linux kernel to avoid the DAD • Select new router aggressively to avoid NUD • Without the kernel modification：2~40s • With the kernel modification：within 450ms • For some real-time applications, this may be too high