Transcript Document
QoS Translation and Signaling Protocols Edge Device Design for Heterogeneous Network PI: Klara Nahrstedt, Roy Campbell (klara,[email protected]) RA: Yuxin Zhou ([email protected]) 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 Architecture for 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 RSVP Control ATM Control FST* Control Plane Data Plane (per Flow) Cell Buffer * Flow State Table End-to-End QoS Signaling Protocol Times Times Get Selector Byte From RESV Times RESV (QoS Reserve) RESV Times Choose NSAP Addr. Add Selector Byte to RESV Wait for ATM Connection Request Make ATM Connection Request (QoS Reserve) Accept ATM Connection Store Port in Flow Record RESV ATM Connection ALLOCATE Sender Store Port in Flow Record Ingress Edge Device ALLOCATE ALLOCATE Egress Receiver Edge Device 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 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 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 downstream 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 Controlled Best Effort Service Load Service ATM CBR Service ABR Cable Modem UGS Nrt-Polling Best Effort UBR 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