TekelecDSR Presentation GSIF

8/20/2019 TekelecDSR Presentation GSIF

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Diameter Signalling Router

David PrinceDirector Technical Pre-Sales, APAC

Tekelec. For What’s Next.

2010 12 2


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Outline

› Diameter Background› Use of Diameter in LTE/IMS/3G› Diameter Agents› The Tekelec Diameter Signaling Router – Use Cases for

International Interconnect Carriers

› Summary


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Signaling Protocol Evolution

› Diameter and SIP become the dominant signaling protocols› SCTP “point-to-point” connections remain

Mobility and Subscriber Management

Application and Session Control


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Mapping of SS7 to IP protocols

› CAP* - 2G/3G CAMEL prepaid functions in future via Diameter, VAS functions of CAMELvia SIP (= INAP)

› MAP* - AAA and mobility in future via Diameter, Messaging (SMS) via SIP

SIPISUP

INAP

Call &

ServiceControl

DiameterMAP*

CAP*

Mobility &ChargingControl


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Comparing the SS7 and Diameter Protocol Stacks

› Diameter is the successor of Radius, originally used for AAA› Diameter acts as an “envelope” for applications (= interfaces)

MTPSCCP

TCAP

MAPCAP

INAP

IPSCTP

Diameter

S6, S9, S13,Gx,Gy,Gz

Cx,Dx,Sh,Dh

Rx,Rf,Ro,

DiameterProxyAgent

DiameterRelayAgent


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Diameter Fundamentals

› Defined by RFC 3588› IP-based AAA protocol designed for easy extensibility via the

definition of new Applications [interfaces], Commands[messages], and Attribute-Value Pairs (AVPs) [parameters]

› 3GPP has defined many new Diameter applications for use inIMS, LTE, and 3G

› Routing, signaling network management and congestioncontrol not as robust as SS7› Requires security via TLS or IPsec, but these are not always

used in practice

› Defines clients, servers, and 4 types of core agents


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Selected Diameter Interfaces in LTE and IMS

Foreign LTE Domain

Home LTE/IMS Domain

Foreign GPRS Domain

S13

S6a S9

S6a

GxGz

Gy

Cx

Sh

Rx

Ro

Rf

Rc Re

EIREIR

vMME vPCRF

PGW

AF

ABMF RF

OFCF

S6d

MAP-DiamIWF vSGSN

vS4-SGSN

OCF

EPC EquipmentCheck

AS Accessto HSS

IMS PCC

IMSCharging

EPCCharging

IMSRegistration

EPC MobilityManagement

MME

I/S-CSCFPCRF P-CSCF

IP-SM-GWAAAHSSHSSSLFSLF


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Types of Diameter Agents

› Relay Agent – Routes messagesbased on Realm (domain), Host,and Application. Maintainstransaction state only.

› Proxy Agent – Similar to Relay,but might also look inside themessage for routing decision,or modify the message. Mightmaintain session state.

› Redirect Agent – Returns routinginformation and then drops out ofthe loop.

› Translation Agent – Proxy agentthat translates between twoprotocols, such as Diameter-MAP.

MAPMessage Request

Answer

NE ServerTranslationAgent

MAPResponse

Request

Answer

Request

Answer

Client ServerRelay/ProxyAgent

Request

Request Redirect

Answer

ServerClient

RedirectAgent


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Diameter Comparison to SS7

Characteristic SS7 Diameter

Routing › Each message independently routed› Answer message does not contain

routing info and follows same pathas associated request

Signaling network management(SNM) and Congestion control

› Network-wide› Dedicated SNM messages› Route around failed paths› Congestion levels and traffic

priorities defined

› Hop-by-hop› No dedicated SNM messages› Failures ‘discovered’ with each new

request

› Relies on reliable transport› No defined traffic priorities

Subscriber number based routing › GTT can be used by upper layers

› Specialized, app-specific proxiesrequired

DRA for PCRF

HSS address resolution for EPC andIMS

Robustness › Wide-scale deployment; years ofexperience› Early days; lots of prove-in still

required


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Challenges Raised by Diameter

› Complexity and scalability of managing large number ofSCTP/Diameter connections

› Deficiencies with respect to network management and congestioncontrol in Diameter› Lack of wide-scale deployment and proven robustness of Diameter

› Need for address resolution function to support mapping subscribersto HSSs, particularly for LTE mobility management

› Need to provide PCRF load-sharing and binding for policy› Need for single point of interconnect to other LTE networks to simplify

routing and provide security

› Need to provide for roaming to non-LTE (2G/3G) networks› Need for visibility of critical Diameter interfaces


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Selected DSR Use Cases for Interconnect Carriers

› LTE RoamingLTE-to-LTE

LTE-to-2G/3G Roaming• MAP-Diameter Interworking

Topology Hiding

Roaming Steering

› Diameter Mediation› Centralized Monitoring


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GSMA – LTE Roaming Guidelines

› Defined in GSMA PRD IR.88Defines need for a Diameter agent at the point of networkdemarcation

S4SGSN

vPCRF

VPMN HPMN

ProxyAgent

hPCRF

ProxyAgent

S6a

S6d

S9

GRX/IPXMME HSS

ProxyAgent


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MME MME MME

Simplified S6a Network

Operator_N

HSS BEHSS BE HSS BEHSS BE HSS BEHSS BE HSS BEHSS BE

HSSFE

HSSFE

HSSFE

HSSFE

HSSFE

HSSFE

HSSFE

HSSFE

Operator_2

Operator_3

Operator_N+1

Roaming HubProvider

DSR

MMEMME

MME

DSR

MMEMME

MME

DSR

MMEMME

MME

DSR

MMEMME

MME

DSR

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

HSSHSS

DSR


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DSR Routing

› DSR allows the operator to define routing rules based on combinationsof the following data elements:

Destination-based: Realm, Host, and Application-IDOrigination-based: Realm, Host, and Application-IDCommand-CodeIMSI Address

› DSR allows the operator to prioritize rules for cases where a DiameterRequest may match multiple user defined rules

› SupportsSecurity:

• IP Sec,

• Single point of interconnect,

• Screening functions

Topology hiding,SCTP multi-homing


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S6d

S6d (R8SGSN only)

SGi

Gb Iu

GpGr

Gr

PDN

HLR PGW

SGSNR7/R8

EPS HPMN

2G/3G VPMN

HSS

IWF

Alternatives

UTRANGERAN

MAP-Diameter Interworking Function (IWF)

Target Use Case – Roaming to non-LTE network;Visited SGSN uses Gr interface (MAP)


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Diameter Mediation

› Designed to be a highly extensible protocol, new Diameterapplications and enhancements to existing applications will becommonplace

› Inevitably, vendor-specific implementations and ongoingenhancements will present interoperability issues as theseenhancements and new applications are introduced in existingDiameter networks

› DSR will support a Diameter mediation framework to assistwith timely resolution of interoperability issues

Vendor A

›DSRVendor B

Request A RequestA(B)

AnswerBAnswerB(A)

DiameterMediation

Framework


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Diameter Intelligence Hub

HSSHSS

S4 SGSNS4 SGSN MMEMME

IMS

EIR

AAA

ePDGSWm

S6d/a Swx

S13

S6d

Gy

Gz

SWx/a/m

Gy, Gz,Gx

Gx, Rx,S9

S6aS13

Rx,Cx,Dx,Sh,

S9

HSS

S4 SGSN

PDN Gw

PCRF

OCS

OFCS

IP networks

MME

HLR

vSGSN vPCRF

vMMEMAP

› Tekelec’s Diameter Intelligence Hub (DIH) isfully integrated with the DSR, eliminating theneed for additional probes and taps

› The DIH leverages virtualization technologyto deliver accounting and troubleshootingcapabilities in a common blade deploymentwith each DSR NE

› Leveraging DSR’s role as an IPSec securityassociated endpoint, visibility is maintainedover IPSec encrypted interfaces

Data Feed:• Accounting (message count like suDR)• xDR, KPI, Alarms to 3 rd party incumbent OSS/BSS systems

Troubleshooting:• Mobility Management incl. 4G/3G hand-over performance• Authentication Management

Analytics:(sample of KPIs generated from S6a, S6d):

• Update-Location-Request/Answer• Cancel-Location-Request/Answer• Purge-UE-Request/Answer• Insert Subscriber Data Request/Answer• Delete-Subscriber-Data-Request/Answer• Reset-Request/Answer• Notify-Request/Answer- For change of PDN-GW• Authentication-Information-Request/Answer

17 I Tekelec. For What’s Next. Tekelec Confidential


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Conclusions

› Diameter (and SIP become) the dominant signaling protocols› Diameter interconnect required to support

LTE Roaming

PCC (3GPP R9) connectivity between hPCRF and vPCRF› Need a robust signalling framework for DIAMETER

Provided by the Diameter Signaling Router Solution

› Main DSR Use Cases for International Interconnect CarriersGateway to other networks to support roaming and topologyhiding

• Possibly include MAP Interworking Function for interconnection with2G/3G networks

Mediation of Diameter variants in a multi-vendor environmentProbeless monitoring and network intelligence data collectionpoint for the Diameter network


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DSR collateral available

› Application Handbook› Product Brief› Download at www.tekelec.com


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Acronyms

ABMF Account Balance Mgmt. Function

AF Application Function

CSCF Call Session Control Function

DNS Domain Name System

DRA Diameter Routing Agent

EIR Equipment Identity Register

EPC Evolved Packet Core

GGSN Gateway GPRS Support Node

GRX GPRS Roaming eXchangeHSS Home Subscriber Server

IMC Inter-MP Communication

IMS IP Multimedia Subsystem

IPX IP Packet eXchangeIWF InterWorking Function

LTE Long Term Evolution

MME Mobility Management Entity

OCF Online Charging Function

OFCF Offline Charging Function

PCRF Policy and Charging Rules Function

PDN Packet Data Network

PGW PDN GateWay

RF Rating Function

SB Service Broker

SBCF Session Based Charging Function

SCTP Stream Control Transmission ProtocolSGSN Serving GPRS Support Node

SGW Serving GateWay

SLF Subscription Locator Function

SSR SIP Signaling RouterTCP Transmission Control Protocol

TLS Transport Layer Security

UE User Equipment


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References

› IETF 3588bis – Diameter Base Protocol› 3GPP TS 29.272 (v8.3.0) – Mobility Management Entity (MME) and Serving GPRS Support Node

(SGSN) related interfaces based on Diameter protocol (Release 8)

› GSMA PRD IR.88 – “LTE Roaming Guidelines”, v1.0

› 3GPP TS 23.003 (v8.6.0) – UMTS; Numbering, addressing and identification (Release 8)› 3GPP TR 29.909 (v8.1.2) – Diameter-based protocols usage and recommendations in 3GPP(Release 8)

› 3GPP TS 33.210 (v8.3.0) – 3G Security; Network Domain Security; IP network layer security(Release 8)

› 3GPP TS 23.204 (v9.0.0) – Support of Short Message Service (SMS) over generic 3GPP InternetProtocol (IP) access (Release 9)› 3GPP TR 29.805 (v8.0.0) – InterWorking Function (IWF) between MAP based and Diameter based

interfaces, (Release 8)

› 3GPP TS 29.305 (v9.0.0) – InterWorking Function (IWF) between MAP based and Diameter basedinterfaces, (Release 9)

› 3GPP TS 23.292 (v9.4.0) – IP Multimedia Subsystem (IMS) centralized services; Stage 2,(Release 9)

› 3GPP TS 23.203 (v9.3.0) – Policy and charging control architecture, (Release 9)


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Selected Diameter Interfaces in LTE and IMS

Interface Endpoints

S6a MME HSS

S6d HSS vSGSN (Rel 8)

S13 MME EIR

S9 hPCRF vPCRF

Rx PCRF AF, P-CSCF

Gx PGW PCRF

Gy PGW OCF

Gz PGW OFCF

Cx I/S-CSCF HSS

Sh AF, IP-SM-GW HSS

Rf P/I/S-CSCF, AF OFCF

Ro S-CSCF, AF OCF

Rc OCF ABMF

Re OCF RF


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Contact Details

David Prince

Director Technical Pre-Sales, APACMobile: +61.448.186.288

E-Mail: [email protected]


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S6a

S9

GRX/IPX

MME

S4SGSN

HSS

vPCRF hPCRF

S6d

VPMN HPMN

ProxyAgent

ProxyAgent

Diameter Agents in 3GPP and GSMA

MMEMMEMME ...

InnerDiameter

Relay Pool

BorderDiameter

Relay Pool

HSS

Inter-Operator DiameterInfrastructure

3GPP TR 29.909 – Diameter-basedprotocols usages andrecommendations in 3GPP

• Defines need for Diameterinfrastructure to simplify the S6 and

S9 networks3GPP TS 23.203 – Policy andcharging control architecture

• Defines Diameter Routing Agent todirect all messages for the same IP-CAN session to the same PCRF

GSMA PRD IR.88 – LTE RoamingGuidelines

• Defines need for a Diameter agentat the point of network demarcation

PLMN

Diameter (PCRF) realm

S-GW

P-GW

AF

PCRF PCRF

PCRF

DRADiameter (PCRF) realm

PCRF PCRF

PCRF

DRAGx, Gxa, Gxb, Gxc, Rx

Non-3GPPGW

ePDG

24 I Tekelec. For What’s Next. Tekelec Confidential

Documents

TekelecDSR Presentation GSIF