Signaling Packet Routing for Layer 3 approach in UMB-HRPD/1x interworking KDDI Corporation, Tsunehiko Chiba, Osamu Kobayashi, Kazushi Imamoto, Notice KDDI grants a free, irrevocable license to 3GPP2 and its Organization Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner’s name any Organizational Partner’s standards publication even though it may include portions of the contribution; and at the Organization Partner’s sole discretion to permit others to reproduce in whole or in part such contributions or the resulting Organizational Partner’s standards publication. KDDI is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by the contributors to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on the contributors. Contributors specifically reserve the right to amend or modify the material contained herein and nothing herein shall be construed as conferring or offering licenses or rights with respect to any intellectual property of the contributors other than provided in the copyright statement above.

General Requirements Signaling packet routing for L3 approach should be localized within AGW. –In PMIP or CMIP roaming case, routing path between AT and SFF (Signaling Forwarding Function) via LMA or HA is inefficient. SFF is located visited network. HA/LMA is located home network. –Routing to the home network may affect existing protocols. If network delay b/w visit and home is long, the timer used in air-interface, IOS, PPP or CMIP may expire. –SFF address should be assigned by the localized DHCP rather than the normal DHCP (for P-CSCF address, etc.). L3 approach shall be secured. –Need a verification mechanism that all messages through the secured tunnel are sent from an authorized AT. S01A_UMB-HRPD HO Security Analysis.pdf –All messages in L3 approach should be exchanged through a secure tunnel between AT and SFF. DNS-query for finding a RAN-Lite as well as Air/IOS/PPP signaling messages should be secured. Additional internal DNS server address(es) for interworking should be provided during IKEv2 negotiation.

General Requirements (cont.) L3 approach should support the roaming situation. –If the AGW or PDSN assigns a private IP address to the AT and the SFF uses global IP address, the AGW or PDSN shall support the NAT function. There is a possibility that the same private IP address is assigned to both home AT and roaming AT if CMIP or PMIP is used. –The NAT function at the AGW or PDSN shall bind the global IP address to the RAN-PMIP or A10 tunnel, respectively.

1.AT detects another system 2.AT acquires SFF address by the localized DHCP* 3.IKEv2 authentication and DNS address assignment b/w AT and SFF 4. Look-up the RAN-Lite address through DNS** 5.HRPD session negotiation and Pre-PPP setup with the PDSN via the AGW Proposed procedure (UMB->HRPD/1x) Inter-RAT HHO *RFC may be required for DHCP new option This procedure happens in HRPD case. **DNS query parameter is FFS.

Example: UMB->HRPD Interworking LMA PCF eBS AN UMB PDSN SRNC AGW HRPD ANAAA SFF SFF: Signaling Forwarding Function 3: IKEv2 (authentication, Tunnel Inner Address and internal DNS server address assignment) AN/PCF -Lite 1: AT detects HRPD system over the UMB air-interface Localized DHCP 2: AT obtains the SFF address DNS for HRPD interworking 4: AT lookup AN/PCF- Lite address 5: AT starts HRPD session negotiation with AN/PCF- Lite and PDSN AGW performs NAT when source address is private IP and destination address is SFF. AGW binds the SFF address to the RAN-PMIP tunnel. The SFF and AN/PCR-Lite can be consolidated. Stage 2 proposal –X xxx KDDI_X.P IP tunnel establishment for UMB-HRPD interworking Stage 2