02. DSR_Overview July2012

Tekelec Confidential1 I Tekelec. For What’s Next.This document is for informational purposes only, and Tekelec reserves the right to change any aspect of the products, features

or functionality described in this document without notice. Please contact Tekelec for additional information and updates.

DSR & Diameter Protocol Overview

This document is for informational purposes only, and Tekelec reserves the right to change any aspect of the products, features


Tekelec Confidential2 I Tekelec. For What’s Next.

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


Comparing the SS7 and Diameter Protocol Stacks

� Diameter is an IP based protocol defined by IETF RFC 3588

� Diameter acts as an “envelope” for applications (= interfaces)

MAP

CAP

INAP

TCAP

SCCP

MTP

S6, s9, s13,

Gx, Gy)

Diameter

TCP/SCTP

IP/IPsec

� SS7 Entities vs. EPC Entities:

SS7

� Switching Transfer Point (STP)

� Home Location Register (HLR)

� Mobile Switching Center (MSC)

� Service Control Point (SCP)

EPC

� Diameter Relay Agent (DRA)

� Home Subscriber Server (HSS)

� Mobility Management Entity (MME)

� Policy & Charging Rules (PCRF)


Diameter Comparison to SS7

Characteristic SS7 Diameter

Routing › Each message independently routed

› Answer message does not contain

routing info and follows same path

as associated request

Signaling network management

(SNM) and Congestion control

› Network-wide

› Dedicated SNM msgs

› Route around failed paths

› Congestion levels and traffic

priorities defined

› Hop-by-hop

› No dedicated SNM msgs

› 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 proxies

required

� DRA for PCRF

� HSS address resolution for EPC and

IMS

Robustness› Wide-scale deployment; years of

experience

› Early days; lots of prove-in still

required


Diameter Fundamentals

� Defined by RFC 3588

� Designed as an improved version of Radius (AAA). Like RADIUS, aDiameter message, has a payload which is a collection of attributevalue pairs. It is peer-to-peer protocol.

� Diameter is defined in terms of a base protocol and a set ofapplications. This design allows the base protocol to be extendedto new applications. The base protocol provides basic mechanismsfor reliable transport, message delivery, and error handling.

� The base protocol must be used in conjunction with a Diameterapplication. Each application relies on the services of the baseprotocol.

� 3GPP has defined many new Diameter applications for use in IMS,LTE, and 3G.

� Requires security via TLS or IPsec, but these are not always usedin practice.

� Use Connection oriented Transport (TCP or SCTP based)


Diameter Base Protocol and Applications

� Base Protocol Handles:

� Connectivity (Peers and Routing)

� Application Support (Application session management etc.)

� Data as collection of Attribute Value-pair (AVP)

� Applications

� Built on top of base protocol

� Purpose specific

� Each application must have an Application-ID (assigned by IANA)

- Example: 16777251 is S6a/S6d Interface Application

� Application-ID may also be used for message routing

S6

Applications

Other

Applications

Gx

Applications

Rx

Applications

Diameter Base Protocol

(RFC 3588)


Mobile Core Network Model

SGW

SGW

PGW

GGSN

OFCS

OCS

MME

MME

HSS/UDB

HSS/UDB PCRF

PCRF

IP Routing

Network

IP network perspective

Might look simple, but reality is more complex


Diameter is the New Signaling Language

MME

SGW

HSS

GGSN

PCRF

PGW

OCS

Mobile core elements communicate with each other

using Diameter signaling

IP

SCTP/TCP

Diameter


IP Routing

Network

Mobile Core Network Model

SGW

SGW

PGW

GGSN

OFCS

OCS

MME

MME

HSS/UDB

HSS/UDB PCRF

PCRF

Diameter connectivity perspective

Diameter Connection

IP

SCTP/TCP

Diameter

A Diameter connection is point-to-point


Mesh Network Topology

From a Diameter signaling perspective, the

previous mobile core was implemented as

a mesh network (fully or partially connected

network)

Diameter Signaling Issues

• Traffic Management

• Fault Management

• Route Management

• Scalability

• Interworking

• ))..

Mesh network topology does not support a

robust mobile core network

Unchecked

signaling traffic

can overwhelm

any node


IP Layer

Diameter Layer

Creating a Diameter Network Layer

Application

Layer


Tekelec View of Diameter Signaling Core

SGW

SGW

PGW

GGSN

OFCS

OCS

MME

MME

HSS/UDB

HSS/UDB PCRF

PCRF

IP Routing

Network

Diameter connectivity perspective

DSR

DSR

Redundant and

highly available

Diameter Routing

Agent

Hierarchical

Diameter routing

topology over IP

packet routing

network


Diameter Agents in 3GPP and GSMA

� 3GPP TR 29.909 – Diameter-based protocols usages and recommendations in 3GPP

� Defines need for Diameter infrastructure to simplify the S6 and S9 network

� 3GPP TS 23.203 – Policy and charging control architecture

� Defines Diameter routing agent to direct all messages for the same IP-CAN session to the same PCRF

� GSMA PRD IR.88 – LTE Roaming Guidelines

� Defines need for a Diameter agent at the point of network demarcation

� New proposals to add Gy as a roaming interface for online charging

Border Diameter

Relay Pool

Inter-operator Diameter

Infrastructure

Inner Diameter

Relay Pool

S4

SGSN

vPCRF

VPMN HPMN

Proxy

Agent

hPCRF

Proxy

Agent

S6a

S6d

S9

GRX/IPX

S-GW

P-GW

Non-3GPP

GW

ePDG

GGSN

Gx, Gxa, Gxb, Gxc, Rx

Diameter (PCRF) realm

DRADRA

Diameter (PCRF) realm

DRADRA

PLMN

MME MME MME

MME

PCRF

PCRF

HSSHSS

HSSHSS

13 I Tekelec. For What’s Next.

Proxy

Agent


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 / GGSN PCRF

Gy PGW / GGSN OCF

Gz PGW / GGSN 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


Selected Diameter Interfaces in LTE (EPC) and IMS

Foreign LTE Domain

Home LTE/IMS Domain

Foreign GPRS Domain

S13

S6a S9S6d

GxGz

Gy

Cx

Sh

Rx

Ro

Rf

Rc Re

EIR

vMME vPCRF

PGW /

GGSN

AF

ABMF RF

OFCF

MAP-Diam

IWF

vSGSN

vS4-SGSN

OCF

EPC Equipment

Check

AS Access

to HSS

IMS PCC

IMS

Charging

EPC

Charging

IMS

Registration

EPC Mobility

Management

MME

I/S-CSCFPCRF

P-CSCF

IP-SM-GWAAAHSSHSS

SLF

Gr

Policy

SPR

Sh


The New Diameter Network


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network

ManagementCongestion

Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS

Policy Proxy3G/LTE/IMS

(Gx/Gxx/Rx/S9)

Roaming ProxyLTE/IMS

(S6/S9)

Address

Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)

PCRF

Topology Hiding

DSR: a Multi-Solution Diameter Agent

IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening

Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network

Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing

OCS/OFCS Proxy3G/LTE/IMS

(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Scalability and

Connection

Management

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

Centralized

Routing and

Load Sharing

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


1- Connection management

Gx+ and Gy

DRALB

DRALB

DRALB

DRALB

DRALB

DRALB

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

10 PCRF’s/Site

8 SBCF’s/Site

10 PCRF’s/Site

8 SBCF’s/Site

10 PCRF’s/Site

8 SBCF’s/Site

Load balancers

can vary from

connection

balancers to

specialized

Diameter proxies

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

PCRF

PCRF

PCRF

PCRF

PCRF

PCRF


Connection management example

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

10 PCRF’s/Site

8 SBCF’s/Site

10 PCRF’s/Site

8 SBCF’s/Site

10 PCRF’s/Site

8 SBCF’s/Site

Enables future

separation of SBCF

and ABMF via

Diameter

interconnect

Addresses connection

limitations at GGSN

Eliminates need for

load balancers in front

of PCRFs and SBCFs

SBCF/ABMF

SBCF/ABMF

SBCF/ABMF

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

GGSN

PCRF

PCRF

PCRF

PCRF

PCRF

PCRF

DSR

DSR


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Request Routing Parameters

� Routing rules based on combinations of

� Destination-Realm (leading/trailing characters, exact match or wildcard)

� Destination-Host (leading/trailing characters, exact match, wildcard or presence/absence)

� Application-ID (exact match or wildcard).

� To facilitate screening, application invocation, and enhanced routing, additional data elements can be used:

� Command-Code (exact match or wildcard)

� Origin-Realm (leading/trailing characters, exact match or wildcard)

� Origin-Host (leading/trailing characters, exact match or wildcard)

� Rules prioritization enabled for Request matching multiple use defined rules

� Rule Action supported when this rule is invoked

� Route to Peer via Route List Table

� Route to Local DSR Application

- The message will be routed to the local DSR application identified by the rule’s Destination-Application-ID field

� Send Answer Response

- An Answer response will be sent with a configurable Result-Code and no further message processing will occur


Routing & loadsharing example

Peer Routing Table (PRT)

Dest-Realm* Orig-Realm* Appl ID* Dest-Host* Orig-Host*Cmd-

Code*Action

Route List

NamePri

opco1.com homeop.com Don’t care Don’t care Don’t careRoute to

PeerHUB_NW 1

opco2.com homeop.com Don’t care Don’t care Don’t careRoute to

PeerOPCO2_NW 1

homeop.com opco1.com 43 Don’t care Don’t careRoute to

PeerHSS1 1

homeop.com opco2.com 65 Don’t care Don’t careRoute to

PeerMME2 1

Don’t care Don’t care Don’t care Don’t care Don’t careSend Answer

“X”--- 99

Route List Table (RLT)

Route List Name Route Name Pri Weight

HUB_NW HUB_PEER1 1 60



OPCO2_NW OPCO2_PEER1 1 100

OPCO2_NW OPCO2_PEER2 2 100

HHS1 HSS1_SRV1 1 100

MME1 MME1_SRV2 2 100

Active Route Group

Standby Route Group


Routing & loadsharing example

Peer1

Peer2

Peer3

Peer4

Peer5

Peer6

Peer7

W=40

W=30

W=30

W=60

W=40

W=50

W=50

Route Group-1 (Routes with Pri=1)

Route Group-2(Routes with Pri=2)

Route Group-3(Routes with Pri=3)

DSR

Route List-1

Route Group-1

Route Group-2

Route-1, Pri=1, Wt=40, Peer=1




Route Group-3





Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Per-Connection Ingress MPS Control

� This feature provides user-configurable Ingress MPS

control on a per-connection basis, allowing the user to

reserve and limit transaction capacity on each connection.

� This functionality ensures that each DSR peer connection

is provided a guaranteed transaction capacity while also

preventing DSR peers from flooding the network.

Connection Reserved

Ingress MPS

Maximum

Ingress MPS

MPS share

with other

connectionsConnection 1 100 500 400

Connection 2 0 5000 5000

Connection 3 500 500 0


User-Configurable Message Priority

� Message priority profiles allow user-assignment of Priority to Request messages as they ingress the DSR

� Zero (0) is lowest priority

� Two (2) is highest priority

� Answer messages which ingress the DSR are assigned a priority of 3 and are NOT user-configurable

� Each profile supports user-assignment of priority to ingress Request messages based on message content using the strongest matching entry in the profile:

� Application-ID + Command-Code combination

� Application-ID

� All Request messages

� Example Ingress Request Priority Profile:

Application-ID Command-Code

Ingress Request

Priority

S6a AIR 0

S6a * 2

* * 1


Egress Request Routing Based on Priority

� Request routing utilizes message priority and connection

congestion level in it’s connection selection criteria to avoid

sending priority x Requests to connections currently at

congestion-level x+1

Severity of

Congestion

Connection

Congestion

Level

Message

Priorities

Allowed Comment

Most

CongestedCL-3 3

Only allow Answers to be sent on

connection

More

CongestedCL-2 3, 2

Only allow Answers and Pri=2 Requests to

be sent on connection

Least

CongestedCL-1 3, 2, 1

Only allow Answers and Pri=2,1 Requests

to be sent on connection

Not

CongestedCL-0 All

All Requests and Answers can be sent on

connection


Server A5

Client DSR

Server B

1 2

Remote Congestion Control

Phase 1

› Server B becomes congested and replies with DIAMETER_TOO_BUSY (Response 4)

› DSR marks Server B as “Congested” for a user-configurable time. During this time, DSR will not select Server B for new Requests

› Optionally, DSR can re-route Requests receiving DIAMETER_TOO_BUSY responses to an alternate Server (Request 5)

3Target

DSR

4 Congested

Server A3

Client DSR

1 2

Phase 2

› Server B begins responding slowly or the transport path to Server B becomes impaired, resulting in egress transport buffer/queue utilization on the DSR exceeding user-configurable thresholds

› DSR marks Server B as “Congested” until the buffers/queue depths abate to an acceptable level. During this time, DSR will not select Server B for new Requests.

Target

DSR

Server B


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Diameter Mediation via Rules Engine

Peer

N-1

Peer

N+1

Local

Appl

ART/PRTRoute

List Table

(2) (3)

(4) (5)

DSR

(1)

Request

Answer

Processing

(6) Answer(8) Answer

In-line 3rd

Party App

Off-line

3rd Party

App

(4’)

Conditions logically AND’d or OR’d:

• Origin/Destination Host/Realm

presence, value match, partial

value/range match

• Header fields (Appl-ID, CmdCode,

flags, etc.) value match

• Application specific AVPs

presence, value match, partial

value/range match

Actions:

• Add AVP

• Delete AVP

• Modify AVP

• Modify header field

• Route to Local App

• Route to Peer via Route-List

• Send Answer with specified

Result-Code

• Copy message/session

Diameter Rules Engine

trigger points – trigger

one or more tasks, with

priority


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Client Server

DSR

Agent

Agent

1

3

2

4

56

Client

DSR

Server

DSR DSR

12

4

5

Client Server

DSR

Agent

Agent

12

3

45

Timeout

Request Message Re-Routing

Alternate Routing on Answer

� Configurable per Result Code

� Response (3) may be DIAMETER_UNABLE_TO_DELIVER

Alternate routing on transport failure

� Connection failure occurs after message 3 has been sent

� T-bit set on re-routed message to warn of possible duplicate

Alternate routing on timeout

� No response received for message 2

� T-bit set on re-routed message to warn of possible duplicate

3

Target

DSR

Target

DSR

Target

DSR


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


HSSHSS

S4 SGSNS4 SGSN

MMEMME

Diameter Hub for Performance & Intelligence

IMS

EIR

AAA

ePDG

SWm

S6d/a

Swx

S13

S6d

Gy

Gz

SW

x/a/m

Gy, Gz,

Gx

Gx, Rx,

S9

S6a

S13

Rx,Cx,

Dx,Sh,

S9

HSS

S4 SGSN

PDN Gw

PCRF

OCS

OFCS

IP networks

MME

HLR

vSGSN vPCRF

vMMEMAP

Integrated Monitoring into PIC:

› Probeless

� Direct enriched feed from DSR

› Security/Network Integrity

� DSR terminating IP-Sec tunnels from

partners’ networks.

Key Take Away:

LTE Performance Management Integrated In DSR Is A Key Differentiator


Network visibility - features

� Tracing

� Nodal transactions trace across DSR and other network elements (e.g., other DSRs, HSSs, MMEs)

� Full decode of Diameter payload

� Display trace output in ladder diagram

� Extensive tracing filters available (e.g., IMSI, SGSN, etc.)

� Data Feed of xDR records

� NFS and (S)FTP supported

� Correlated records can be exported to any external server

� Filtering

� View actual traffic as xDRs

� Filter through traffic to pinpoint issues

� Alarms

� Alarm forwarding for DIH system alarms via SNMP/email

� Configuration and provisioning

� Web-based GUI providing security, configuration, and application access for DIH

� Support for up to 5 simultaneous users

� Collection and Storage

� Create and store unique records for each desired transaction (PDUs, xDRs)


ProTrace Feature cont.

• Ladder diagram showing

continuous flow between

elements

• Entire screen can be

exported to a .zip file

containing xDRs, PDUs,

and the decode level detail


Tracing Feature Detail

• Single GUI for multi-

protocol, multi-network

call traces

• Powerful filtering

capabilities

Filter results

CDR

PDU

Decode


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation

OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

OCS/OFCS

Address

Resolution


Policy

DRA

Policy

DRA

Policy

DRA

Policy

DRA

Edge

Agent

GW GW

CSCF

Other

Nets

Replication/Messaging

TAS

CSCF

TAS

HSS FEHSS FE

HSS FEHSS FE

HSS FEHSS FE

HSS FEHSS FE

Gx, Rx, S9

Sh

Policy Network Scaling

Edge

Agent

PCRF

PCRF

PCRF

PCRF

PCRF

PCRF

PCRF

Even messages from remote

systems may need to be routed

to same PCRF.

Policy DRA enables PCRF

scalability by load sharing

to PCRFs

S9

Data replication and messaging

enable policy DRAs to act as a

single logical network.

and ensuring that

all messages for the same

subscriber are routed to the

same PCRF.


DSR Policy DRA Overview

� Supports a network of up to 14 (7 pairs) P-DRA DSR NEs. All P-DRAs in

the pool work together as a single logical P-DRA.

� Each pair of P-DRAs supports 120M active sessions.

� Up to 10 Gx sessions per subscriber.

� At most one real-time WAN traversal required to resolve a binding when

>1 pair of P-DRAs deployed (under non-error conditions).

� Performs topology hiding to hide the true identities of the PCRFs from

other elements in the network.

� Enabled for all roaming traffic or for configured list of destinations

� User configures virtual PCRF host ID

� Allows user to configure custom (Experimental-)Result-Codes to be

returned for various error scenarios.


Binding / Session Relationships

� A PCRF can host a large number of sessions

� All of the sessions for a subscriber are “bound” to the same PCRF

� A subscriber may have multiple simultaneous sessions

� P-DRA maintains the relationship between the subscriber and the PCRF

� This relationship is called a binding


Scalability and

Connection

Management

Centralized

Routing and

Load Sharing

Network


Control

TCP/SCTP

IPv4/IPv6

Interworking

Diameter

Variant

Mediation

Network-wide

PCRF Binding

Roaming

Steering

MAP/Diameter

Interworking

HSS/MME/PCRF

Topology Hiding

IPSec

Core & Routing

3G/LTE/IMS


(Gx/Gxx/Rx/S9)


(S6/S9)

Address


OCS/OFCS

Session-based

Routing


(Gz/Rf/Gy/Ro)

OCS/OFCS

Topology Hiding

PCRF

Topology Hiding


IMS HSS

Address

Resolution

LTE HSS

Address

Resolution

HSS

Topology Hiding OCS/OFCS

Address

Resolution

Secure Access

/ Screening


Intelligence

Network-wide

Session

Correlation


4- Offline Charging Proxy – Vz W UC

Site 1

OFCF OFCF OFCF

PGW PGW

OFCF OFCF OFCF. . .

PGW. . .

OFCF

Site 2

OFCF OFCF OFCF

PGW PGW

OFCF OFCF OFCF. . .

PGW. . .

OFCF

DSRDSR

Adding GW/CSCF/TAS

is transparent to OFCFs

Adding OFCFs is

transparent to

PGW/CSCF/TAS

Significant reduction

in number of

connections

CSCF/

TAS

CSCF/

TAS

Rf

Common/centralized :

� OFCF load-balancing

� Rf network intelligence

� Rf troubleshooting

Topology hiding drives

the need for session

stateful routing


Secure

interconnection for

M2M services

Grow

RevenuesEliminate

Signaling

Storms

The Value of Diameter Routing

Load

balancing

� Proxies for: Over-the-Top/Cloud/M2M Services, LTE/3G Roaming,

Policy, Charging, Home Subscriber Server

Congestion and

traffic management

Scale Diameter

transactions

Interworking and

interoperability

Network visibility

Steer

roamers to

preferred

partners

Reduce

revenue

leakage

, Secure

interconnection

for Cloud

services

Secure

interconnection

for OTT Apps


Diameter Market Leadership

Major Policy + SDM Wins

55 Policy customers/43 Tier 1s

46 SDM customers/27 HSS/SPR

300 Million SDM Subs

Expanding Global, Multi-Property

Policy Deployments

19 DSR Customer Wins and Counting – US/Canada/Europe/Asia/CALA

“Tekelec’s Policy Server is at or near the top of the competitive landscape”

“Tekelec is the front runner in the

Diameter signaling control market.”

“The leader in DSC today is Tekelec withJ

roughly 80% market share”

Tekelec has 75-85% market share of

the exploding Diameter Signaling

Controller market

Tekelec Named #1 Independent Policy

Market Leader for Third Consecutive Year


The reasons to implement a DSR

� Complexity and scalability: Difficult to manage large number of SCTP/Diameter

connections without a DSR.

� Congestion Control - Signaling storm will also happen to small networks

� e.g. prevent a failed MME to flood HSS with requests

� IP Router does not perform routing at Diameter Layer:

� Cannot perform effective load balancing

� Cannot perform congestion control

� Diameter Protocol Mediation - devices from different vendors do not always work well

together.

� DSR provides additional features:

� Address resolution function to map subscribers to HSSs, for LTE mobility management

� PCRF load-sharing and policy binding

� OCS load sharing and session binding

� Single point of interconnect to other LTE networks:

� Simplify routing and provide security (IPsec, Topology Hiding)

� Need Diameter Mediation for LTE Roaming

� Visibility of critical Diameter interfaces (Diameter Protocol tracing)


Customer reference

Operator Size

(subs)

Deployme

nt Target

# Nodes MPS

/Node

Connec-

tions/Node

Use Case

Tier 1 NA Carrier “A” 95.5 M 2012 10 20k 200 Core LTE HSS Proxy

Tier 1 NA Carrier “A” 95.5 M 2012 10 100k 2000 Core IMS VoIP Routing

Tier 1 NA Carrier “A” 95.5 M 2012 10 200k 2000 Policy AS DRA

Verizon Wireless 94 M 2011 2 3000 50 Roaming Proxy

Verizon Wireless 94 M 2011 2 160k 8000 OFCS Binding

Verizon Wireless 94 M 2011 6 40k 500 Core LTE/IMS HSS Proxy

Verizon Wireless 94 M 2011 PCRF DRA/MRA

MetroPCS 8 M 2011 2 100 10 Core Proxy

NA Hub Provider “S” n/a 2011 2 40k 10 Hub Roaming Proxy

NA Hub Provider “T” n/a 2011 2 1000 10 Hub Roaming Proxy

Tier 1 APAC Carrier “O” >5M 2012 2 n/a Core Relay/Proxy


Customer reference - lab

Operator Size

(subs)

Deployme

nt Target

# Nodes MPS

/Node

Connec-

tions/Node

Use Case

Tier 1 APAC Carrier “C” 584 M 2012 Lab 25k 50 LTE Routing Trial

Tier 1 NA Carrier “S” 49.9 M 2012 Lab 100 10 LTE Routing Trial

TC n/a 2011 Lab 10k 100 Hub Roaming Proxy

Tier 1 EMEA Carrier “1” >10M 2011 Lab ~200 Core Relay/Proxy

Tier 1 India Carrier “R” >10M 2012 Lab ~15K Core Relay/Proxy,

LTE/IMS HSS Proxy

Tier 1 CALA Carrier “T” >10M 2012 Lab n/a Core Relay/Proxy. Policy

Proxy


Tekelec DSR Key Takeaways

� Most Tier-1 customer deployment references

� Most patents and intellectual properties awarded in the

area of Diameter signaling and routing

� Advanced features set built into our DSR products

� Congestion Control

� GUI based Mediation engine

� Integrated Diameter protocol analysis tool

� Troubleshooting & Protocol tracing

� Tekelec reputation as a signaling leader in SS7 and

Diameter signaling networks

Tekelec Confidential52 I Tekelec. For What’s Next.This document is for informational purposes only, and Tekelec reserves the right to change any aspect of the products, features


Thank You !


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 eXchange

HSS Home Subscriber Server

IMC Inter-MP Communication

IMS IP Multimedia Subsystem

IPX IP Packet eXchange

IWF 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 Protocol

SGSN Serving GPRS Support Node

SGW Serving GateWay

SLF Subscription Locator Function

SSR SIP Signaling Router

TCP Transmission Control Protocol

TLS Transport Layer Security

UE User Equipment

02. DSR_Overview July2012

Documents

Transcript of 02. DSR_Overview July2012