CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Packet Data RoamingCommon ArchitecturePacket Data RoamingCommon Architecture
Richard XuChief Architect
[email protected]+1(408) 834-0217
Aicent, Inc. November 11, 2005
www.cdg.org2
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Background• Reiterate what have been stated:
Problem Statement – CDG Reference Document #79 recommends three
different packet data roaming architectures:• SIP• MIP• L2TP
– Different operators prefer to use different architectures– Different operators are able to support different
combinations of these architectures for inbound roaming partners.
– Not all of these architectures are compatible
www.cdg.org3
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Matrix of combinations
SIP L2TP MIP
SIP NO ISSUE SOLUTION
AVAILABLE
NO SOLUTION, BUT NO KNOWN INSTANCES
L2TP NO RECOMMENDED SOLUTION IDENTIFIED
NO ISSUE NO SOLUTION RECOMMENDED
IDENTIFIED
MIP NO RECOMMENDED SOLUTION IDENTIFIED
NO RECOMMENDED SOLUTION IDENTIFIED
NO ISSUE
Device
Serve Network
• The following matrix identifies incompatibilities• “Device” indicates the technology preferred by the roaming device• “Serve Network” indicates the network technology available in the visited operator’s network
www.cdg.org4
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Extra IP Routing Issues
Home network insists outbound roaming traffic coming back from CRX
Home network allows outbound roaming traffic from Internet
Serving network routes all inbound roaming user traffic to Internet for accessing home services
No RECOMMENDED SOLUTION
No ISSUE
Serving network routes all inbound roaming users traffic via CGX
NO ISSUE No RECOMMENDED SOLUTION
Home Network
Serving Network
www.cdg.org5
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Common Architecture
• Incorporate most roaming scenarios into a common recommended architecture for each CDMA operators based on existing CRX principles
• Simplify the provisioning process
• Future applications proven
www.cdg.org6
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Definition of roaming service elements• At operator premise:
– Core Subnet (CS): PDSN/FA/LAC, HA, AAA, MMSC(MM4 Interface)
– Service Subnet (SS): Application Servers (WAP, PoC Server, MMSC, Email)
– Roaming-in Subnet (RIS): IP Subnet assigned to inbound roamers
PDSN HA
AAA LNS
MMSC
WAPPoC
Roaming-In Sub
BG
FW/GW
CRXCore Sub
Service Sub
Internet
Internet
www.cdg.org7
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Definition of roaming service elements
• At CRX premise:
– Core Backbone: routing for Core Subnet traffics
– Virtual Home Subnet: subnet for hosted roaming elements, e.g. LNS for L2TP
PDSN HA
AAA LNS
MMSC
WAPPoC
Roaming-In Sub
BG
FW/GW
CRXCore Sub
Service Sub
Core Backbone
BGProxy AAA
Virtual Home
LNS
FW/GW
Operator
Internet
Internet
www.cdg.org8
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
New Service Element from CRX• At CRX premise:
– Virtual Home Subnet• LNS fulfilling L2TP that is not supported by home network• Tunnel connection to Home network• Internet Access
PDSN
AAABG
CRXVisited
Core Sub Core Backbone
BGProxy AAA
Virtual Home
LNS
BG
MMSC
WAPPoC
GRE
BG
GRE
RISHome
Service Sub
User Traffic
GRE TunnelL2TP Tunnel
www.cdg.org9
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Common Architecture for both CRX and Operator • At operator premise:
– GRE Tunnel terminating point (router) as extra element
• GRE Physical end-point (IP) belonging to Core Sub (routable via CRX backbone)
• At CRX Virtual Home Subnet:
– Two GRE tunnel terminating points (routers)
• One tunnel to carry Service Sub routes
• The other tunnel to carry RIS routes
– CRX only routes core sub and GRE tunnels traffics compliant with Doc#94
– Together with LNS in Virtual Home, the architecture resolves most mismatched cases except MIPSIP, where MIP Client is required to fallback SIP
BG Core BackboneBG
GRE GRE Tunnel for Service
Sub
Roaming-In Sub
Service Sub
Core Sub
RISService
SubsRouting
Mgr.
GRE GRE
GRE Tunnel for RI-Sub
Virtual HomeOperator
LNS
www.cdg.org10
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Roaming Scenario: SIPL2TP• Home Operator exchanges its service routes with virtual home via service
tunnel if enforcing roaming-in via CRX.• CRX injects tunnel related attributes in RAIDUS reply package to trigger
visiting PDSN/LAC to build L2TP tunnel with LNS in virtual home.• User traffic is either routed via service tunnel or internet depending on
routes availability at virtual home.
PDSN
AAABG
CRXVisited
Core Sub Core Backbone
BGProxy AAA
Virtual Home
LNS
BG
MMSC
WAPPoC
GRE
BG
GRE
RIS
Home Service Sub
Service Tunnel
L2TP Tunnel
FW/GW
Internet Internet
Service Subs
www.cdg.org11
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Roaming Scenario: L2TPSIP• Home Operator exchanges its service routes with virtual home via service
tunnel if enforcing roaming-in via CRX.• CRX remotes tunnel related attributes in RAIDUS reply package to ensure
SIP.• Visited Operator assigns inbound roamer with IP within RIS, and routes to
GRE tunnel router where user traffic is either routed to virtual home or Internet depending on the routes availability managed by virtual home.
PDSN
AAABG
CRX
Core Backbone
BGProxy AAA
Virtual Home
GRE
BG
MMSC
WAPPoC
GRE
BG
GRE
RIS
Home Service Sub
Service Tunnel
RIS Tunnel
FW/GW
Internet Internet
Roaming-In Sub
GRE
Visited Core Sub
Service Subs
www.cdg.org12
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Roaming Scenario: MIP SIP/L2TP
• MIPSIP/L2TP– Assuming MIP Client supports the fallback-to-SIP
features– The scenario is similar to either L2TPSIP or
SIPL2TP, depending on home network preference
• SIP/L2TP MIP– Assuming PDSN in mobile IP only visited network
supporting either SIP or L2TP– The scenario is similar to either L2TPSIP or
SIPL2TP, depending on home network preference
www.cdg.org13
CDMACelebrat ing T en Y ears of
Commercial Success and I nnovat ion
20051995
Summary• Introducing Virtual Home with hosted LNS and GRE tunnel
endpoints at both Virtual Home and operator premises help to bridge the gap among different roaming scenarios
• At operator premise, extra roaming element, the GRE router, requires minimum provisioning comparing to handling all different roaming scenarios
• CRX plays more mediation roles to enhance experience of CDMA data roaming
• The new revised architecture serves as interim solution until all PDSN could support all access requests. No impact on the future architecture, where CRX would just serve as core backbone for core subnets