diameter and diameter roaming

1 © NOKIA diam-roam.PPT/ 18 December 2002 / John A. Loughney

Diameter and Diameter Roaming

John Loughney

Research Manager

Nokia Research Center

[email protected]


AAA & Diameter

• Next generation Authentication, Authorization & Accounting protocol

• Consists of base specification and applications• MIP• Network Access Server (Dial-up / PPP / SLIP environment)• SIP Services• Accounting Extensions


Standard RADIUS Model


Diameter Roaming


How It Works

• The user requests service from the remote ISP, which in tern requests the user’s credentials.

• The user submits ID, password and address of his home-agent. The remote server performs mutual authentication with the home-agend and forwards the user’s credentials.

• The home-agent accepts the user’s credentials and then tells the remove ISP to grant access to the user.

• Subsequently, the two ISPs update their call accounting records.


AAA Elements

• Diameter Node • A host that implements the Diameter protocol, and acts either as a

Client, Agent or Server.

• Broker • A business term used in AAA infrastructures. A broker is either a relay,

proxy or redirect agent, and operated by roaming consortiums.

• Diameter Agent • A host that provides either relay, proxy, redirect or translation services.

• Diameter Client • A device at the edge of the network that performs access control. An

example of a Diameter client is a Network Access Server (NAS) or a Foreign Agent (FA).

• Diameter Peer • Node to which a given Diameter Node has a direct transport connection.

• Diameter Server • A server that handles authentication, authorization and accounting

requests for a particular realm.


Diameter Connections and Sessions

Server Serverrelay

Peer connection A Peer connection B

User session X


Translation of RADIUS to Diameter

NASHome Server

Translation Agent

RADIUS Req Diameter Req

RADIUS Ans Diameter Req


Diameter Proxy Example

NetworkAccess Server

Primary Proxy Server

Backup Proxy Server

Primary Home Server

Backup Home Server

local service provider

home service provider


Diameter Extensibility

• Diameter tries to preserve Radius -like flexibility

• Diameter base commands and AVPs defined in the base spec

• Diameter extension can define new commands and AVPs.

• Examples are:• NASREQ• MOBILE-IP• 3GPP Credit Control• 3GPP Multimedia Application

• New AVPs can be added


AAA-SIP in 3GPP Rel. 5

SGW

UE P-

CSCFI-

CSCF

MGCF

Gm Mw Mw

SLF

Dx Cx

HSS AS

Cx

MGW

Mc

Mj

Mi

SIP

SIP

Diameter

Megaco

Mr

MRFC

GGSN

GoCOPS for

Policy Control

Sh

Visited

Domain

Home

Domain

ISC

MRFP

Megaco

SIP-ISUP

Compression

S-

CSCF

BGCF

Diameter

Diameter


Work to Do

• Diameter Base Specification just submitted.

• Diameter Mobile IPv4 Application nearly ready (needed by 3GPP2).

• Diameter NASREQ Application nearly ready.

• CMS Security Application, needed for e2e security

• AAA Key Distribution

• SIP-AAA Requirements

• Diameter Mobile IPv6 Application

• Diameter Multimedia Application (3GPP rel. 6)

• Diameter Credit Control Application (3GPP rel. 6)


Summary

• Integrating different access technologies (3G, WLAN, DSL, Dial-up):

• increases the potential for increasing subscribers.• increases accesses to services.

• Integrating/harmonizing signaling:• harmonizes network infrastructure.• simplifies network management.• simplifies charging/billing.• simplifies the user experience.


More Info

• http://www.diameter.org/

• I will be heading an NRC program • Access Independent AAA Infrastructure

http://www.diameter.org/

diameter and diameter roaming

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