Research Objectives Create an edge device model –Create edge device model which connects different networks to the Internet a heterogeneous network Understand the End-to-End QoS signaling –Analyze different signaling protocol directions such as sender vs. receiver oriented signaling protocols ATM vs. IntServ/RSVP Translate traffic parameters in the edge device –Translate traffic parameters among IntServ, ATM and CATV service classes GS UGS CBR CLS rt-Polling ABR BES BES UBR Verify the edge device model using OPNET ®

Edge Device Architecture for IntServ/ATM

Flow Control With Token Bucket

End-to-End Signaling Protocol Sender Times Ingress Edge Device Egress Edge Device Receiver Choose NSAP Addr. Add Selector Byte to RESV RESV Wait for ATM Connection Request Get Selector Byte From RESV RESV Make ATM Connection Request Accept ATM Connection Store Port in Flow Record ATM Connection RESV

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 zero Or –PCR is set to be default value –MCR translates to Allowed Cell Rate –Actual transmission rate is controlled by the ATM ABR feedback information

RSVP Application Design

Edge Device Construction

Experiment Results

On Going: IP Over CATV Cable network is getting popular for data communication –QoS is built into MAC layer Bandwidth allocation scheme is asymmetric –Downstream has higher bandwidth than upstream Head-end reserves and allocates up- and down-stream bandwidth –QoS requirement is not initiated by the end-host –Edge device(CMTS) needs to translate the traffic parameters and signals the connection setup

CATV network: Example

QoS Issues QoS Heterogeneity –End User: IntServ –Transmission: Cable network –Backbone: ATM QoS Signal Mapping IntServGuaranteed Service Controlled Load Service Best Effort Service ATMCBRABRUBR Cable Modem UGSNrt-PollingBest Effort

Conclusion Contributions –Model of edge device for IntServ over ATM –Development of edge device architecture Ongoing work –End-to-end QoS signaling in IP over CATV environment –Performance evaluation of the edge device and the QoS method in CATV network