User Plane Roaming

DNS Solution

Page 1

DNS SolutionUser Plane Roaming

LBS Roaming Meeting, San Francisco

November 28, 2006

DNS SolutionUser Plane Roaming

LBS Roaming Meeting, San Francisco

November 28, 2006

User Plane Roaming

DNS Solution

Page 2Trusted User Plane Roaming

• Trusted user plane roaming seems straightforward

• The roaming MS can simply connect with the V-PDE

• Call flow (IS-801-1) same for MS/V-PDE & MS/H-PDE

• However, there is an issue:• MS is provisioned to access the H-PDE

• MS needs to access the V-PDE

• How does the roaming MS know the IP address of the V-PDE?

User Plane Roaming

DNS Solution

Page 3High Level Solution Overview

• If the MS knows its own location…

• It can map its location to the appropriate V-PDE IP address

PDSN

IP address = 66.3.3.34

Visited Operator (Gotham Wireless)

Where am I? Gotham Wireless

Gotham Wireless PDE IP address = 66.3.3.34

V-PDE

IS-801-1

User Plane Roaming

DNS Solution

Page 4Determining Location

• CDMA networks broadcast values that identify themselves uniquely

• System Identification Code (SID)• EV-DO SectorID• Mobile Country Code + Mobile Network Code (MCC+MNC)

• MS has access to these broadcasted values

• MS needs only to map a broadcasted value to the IP address of the V-PDE

User Plane Roaming

DNS Solution

Page 5Mapping Location to V-PDE IP Address

• SID/SectorID information broadcasted by CDMA networks changes over time

• MCC+MNC is constant, but many operators don’t broadcast these values

• Therefore, preferable to resolve mapping on a network server

• DNS solution:• MS creates URL based on network broadcast information

• DNS is provisioned to return IP address of V-PDE for possible URLs

User Plane Roaming

DNS Solution

Page 6DNS Solution Illustrated

• MS receives SID value from radio network• MS creates SID-based URL (SID.Local.PDE)• MS resolves URL to V-PDE IP address via DNS server• MS accesses V-PDE

PDSN

IP address = 66.3.3.34

Visited Operator

V-PDE

DNS

SID=10856

URL=10856.Local.PDE

10856.Local.PDE = 66.3.3.34

IS-801-1

User Plane Roaming

DNS Solution

Page 7

DNS Solution with Mobile IP or L2TP Roaming

Internet

Internet

Home Operator

RAN

PDSN

PCF

Visited Operator

PDSN/FA/LAC

H-DNSServer HA/LNS

V-PDEBSA

V-DNS Server

IS-801 signaling

Network connection

MIP/L2TP tunnel

• Many roaming implementations use Mobile IP or L2TP• Industry direction is Mobile IP (CDG resolution)• In these cases, data traffic is tunneled back to the home operator• H-DNS server or V-DNS server might be used (inconsistent between implementations)• MS accesses V-PDE from home operator (security issue?)

User Plane Roaming

DNS Solution

Page 8V-PDE Port Issue

• Some LBS applications are configured to require PDE access via a unique port

• For the DNS solution, these applications will try and access the V-PDE via this unique port number

• The V-PDE must be configured to accept connections for roaming MS applications on these particular ports

• There could be ongoing operational requirements to reconfigure the V-PDE as new applications come on line

User Plane Roaming

DNS Solution

Page 9Advantages of DNS Solution

• No PDE changes required

• Provisioning of DNS information is relatively minor

• If no MS changes required, then DNS solution is fastest to market

User Plane Roaming

DNS Solution

Page 10Challenges with DNS Solution

• MS Behavior• Can MS/application use network broadcast information to create URL?

• Need to verify with application/handset/chipset providers

• If new MS behavior is required:

– Long delay in getting new MS behavior implemented

– Issue with legacy mobiles

• Inconsistent MS access of DNS server (home vs. visited)• In some roaming implementations, visited operator DNS accessed

• In some roaming implementations, home operator DNS accessed

• Need to coordinate population of DNS servers with MS DNS access behavior

• V-PDE Port Issue• Could require significant coordination and configuration

User Plane Roaming

DNS Solution

Page 11Challenges with DNS Solution (cont.)

• LBS and DNS server operational considerations• LBS operations usually separate from DNS operations• Requires significant coordination between two separate groups

• Security issues• Operators must expose PDEs directly to roaming mobiles• If Mobile IP or L2TP used, there are additional security issues

– Must expose PDE to all mobiles serviced by home operator HA/LNS– This includes non-roaming mobiles in the home operator network

• No home operator awareness of V-PDE access• No home operator logging possible• Hinders any financial settlement process between operators

User Plane Roaming

DNS Solution

Page 12Actions Items

Control plane: L3 (Openwave), operators directly inter-connected?, RSP support of solution #2 (RSP in L3 call flow), full MSCID from RSP ok?, transport of L3

OPWV: gap analysis RLP/control plane, OPWV solution, official standards extension? Sprint to find analysis

User Plane non-trusted: use control plane A/Is

User Plane trusted:

DNS solution: work offline, Qcom check SID lookup, operators free to pursue privatesIP redirection: Iusacell to championPDE interconnection solution: qcom, sprint, telus, = (RPC) transaction, BSA snipppets, IS-801 forwarding (USC = any interconnection scheme)

New initiative: investigate settlement, retail billing, and transport (RSP/CRX) – QCOM to coordinate w/ syniverse, versign (both will work on this), aicent to be contacted