QoS Translation and Signaling Protocols

Edge Device Design for Heterogeneous Network

PI: Klara Nahrstedt, Roy Campbell (klara,roy@cs.uiuc.edu)RA: Yuxin Zhou (z-yuxin@uiuc.edu)

University of Illinois at Urbana-Champaign

Goals• Create an edge device model

– Create edge device model which connects different networks in a heterogeneous network

• Understand the End-to-End QoS signaling – Analyze different signaling protocol directions such as

sender vs. receiver oriented signaling protocols

• Translate traffic parameters in the edge device– Translate traffic parameters among IntServ, ATM and

CATV

• Verify the edge device model use OPNET simulation environment

QoS and the Internet

• Internet is a heterogeneous network– Only Best Effort Service available

• Several network technologies provide QoS– Internet Integrated Services (IntServ):

Guaranteed Service (GS), Controlled Load Service (CLS), Best Effort Service

– ATM: CBR, VBR, ABR, UBR– CATV: Unsolicited Grant Service, rt-Polling

Service, Best Effort, and others

Edge Device Architecturefor IntServ/ATM

• Two-Dimensional Structure– Control Plane

– Data Plane

– RSVP Control

– ATM Control

• RSVP Messages Flow– PATH from RSVP Control

– PATH from ATM Control

– RESV from RSVP Control

– RESV from ATM Control

FST*

Cell Buffer

Control Plane

Data Plane (per Flow)

RSVP Control ATM Control

* Flow State Table

End-to-End QoS Signaling Protocol

Sender

Times Times Times Times

IngressEdge Device

EgressEdge Device

Receiver

Choose NSAP Addr.Add Selector Byte to RESV

RESV

Wait for ATM Connection Request

Get Selector ByteFrom RESV

RESV

Make ATM ConnectionRequest

Accept ATM ConnectionStore Port in Flow Record Store Port in Flow Record

ATM Connection

RESV

RESVRESV

(QoS Reserve)

(QoS Reserve)

ALLOCATE ALLOCATE ALLOCATE

Signaling Protocol Issues

• QoS setup in ATM is sender-oriented but QoS IntServ is receiver-oriented

• Intelligence is built into Edge Device to handle asymmetric end-to-end connection setup

• ATM connection is not established until a RESV message is processed at the Ingress Edge Device

ATM/IntServ Mapping

• CBR parameters to GS parameters– PCR translates to Peak Rate – MCR translates to Average Rate– SCR translates to Bucket Depth

• ABR parameters to CLS parameters– PCR translates to Average Rate– MCR is set to be zeroOr– PCR is set to be default value– MCR translates to Allowed Cell Rate– Actual transmission rate is controlled by the ATM ABR feedback

information

Edge Device Considerations for Cable Network

• Cable network is getting popular for data communications

• Asymmetric bandwidth allocation scheme– Downstream has higher bandwidth than upstream

• Head-end reserves and allocates up- and down- stream bandwidth– QoS requirement is not initiated by an End-System– Edge devices (Cable Modem and CMTS) need to

translate the traffic parameters and signal the connection setup

CATV network: Example

End-to-End QoS in CATV

• QoS Heterogeneity– End User: IntServ

– Transmission: Cable Network

– Backbone: ATM

• Asymmetric requirement for up/down stream– Flow between users inside a cable network contains

both up and down stream network segments

Parameter Mapping for CATV

IntServ Guaranteed Service

Controlled Load Service

Best Effort Service

ATM CBR ABR UBR

Cable Modem

UGS Nrt-Polling Best Effort

Contributions

• Generic Edge Device Architecture

• Edge Device Design for IntServ/ATM

• Edge Device Design for IntServ/CATV/ATM/

• Design and Verification of End-to-end QoS Signaling via OPNET

• Design and Verification of QoS Translation Mappings via OPNET