Supporting IP Multicast Integrated Services in ATM Networks L. - PDF document

1 Supporting IP Multicast Integrated Services in ATM Networks L. Salgarelli and A. Corghi, CEFRIEL {salga, corghi}@cefriel.it D. Witaszek and H. Sanneck, GMD Fokus {witaszek, sanneck}@fokus.gmd.de 2 Overview • Introduction • IP Multicast over ATM: EARTH • Internet Integrated Services over ATM: Issues • Integrated Approach: Multicast Integration Server (MIS) • Service model: quantized heterogeneity • RSVP server • RSVP state modification at the MIS • Sequence of events to establish a QoS point-to-multipoint VC • Conclusions

IP Multicast over ATM: EARTH 3 ATM cloud (MLIS) EARTH_request EARTH_join LIS A Sender LIS B Receiver 1 Receiver 4 EARTH Server Receiver 3 Receiver 2 EARTH_multi Multipoint data VC Point-to-point control VC • IP Multicast / ATM address resolution for Multicast LIS : shortcuts • support of source-specific groups (IGMPv3) and Layer 2 QoS information Internet Integrated Services (IIS) over ATM: Issues 4 • service class mapping solved issue (e.g. IIS Guaranteed service to ATM CBR/rt-VBR) • Receiver heterogeneity: limited (VC space consumption, data duplication) • dynamic QoS renegotiation: end-to-end VC setup necessary • RSVP merging: only at edges of the ATM cloud • shortcuts: transport of ATM addresses with RSVP, RSVP messages still travel hop-by-hop

Integrated approach: Multicast Integration Server (MIS) 5 ATM cloud (MLIS) LIS A LIS B Sender Receiver 1 Receiver 4 Multicast Integration Server Receiver 3 Receiver 2 Multipoint data VC EARTH & RSVP protocol messages Point-to-point control VC • Joint client/server operation of RSVP and EARTH protocols within MLIS Service model: Quantized Heterogeneity 6 QoS level 2 ATM cloud (MLIS) QoS level 1 LIS A Sender Best-effort LIS B Receiver 1 Receiver 6 Receiver 2 Receiver 5 Receiver 3 Receiver 4 • support for a limited number of QoS levels (QoS level: pre-defined set of QoS parameters)

Quantized heterogeneity: support for layered flows 7 Best-effort VC ATM pt-mpt Sender VCs Base-Layer VC (QoS-0) Enhan.-Layer-1 VC (QoS-1) MLIS Rec.7 (QoS-0) Rec.1 (best-effort) Rec.6 (QoS-0) Rec.2 Rec.5 (best-effort) Rec.3 (QoS-0) Rec.4 (QoS-0 + QoS-1) (QoS-0 + QoS-1) RSVP operation within the MLIS: client/server 8 ATM cloud (MLIS) Sender LIS A LIS B Receiver 1 Receiver 4 Multicast Integration Server Receiver 3 Receiver 2 PATH messages Multipoint data VC Point-to-point control VC RESV messages • efficient PATH state distribution, RESV merging • interface to EARTH QoS capabilities

RSVP operation: state modification at the MIS 9 Example: introducing the quantized heterogeneity model PATH message with PATH message the original Traffic with a single Traffic Descriptor plus the Description Sender allowed QoS levels parameter Receiver 1 Receiver 4 Multicast Integration Server Receiver 3 Receiver 2 PATH messages Multipoint data VC Point-to-point control VC • Any administrative policy can be enforced at the MIS Sequence of events to establish a pt-mpt VC 10 (Re-)Sender MIS Receiver 8 : RESV_ERRO 4/6 : RESV_ERRO R (MIS) R (receiver) 8 : RESV 1 : PATH 7 : RESV (M 2 : PATH (ADSPEC) 3 : RESV (receiver) IS) Layer-3 signalling RSVP server 4 : QSSI EARTH server Layer-2 signalling 6B : EARTH_qos_notify 5 : EARTH_m 0 : EARTH_join ulti Control VC 6A : Capacity admission control / Q oS VC setup RSVP vif Layer-2 data Data (Q oS) VC EARTH control endpoint • RSVP/EARTH interface only at ther server: QSSI ( 4 ) • remote Layer 2 capacity admission control ( 5 , 6 ) = ATM VC setup

11 Conclusions • Shortcut support for multicast flows (minimizes Layer 3 processing and resending identical data through the switch due to LIS boundaries) • joint operation of Layer 2 (EARTH) and Layer 3 protocol (RSVP), however with a strict functional separation • RSVP: no changes to protocol semantics (additional protocol objects, modified Traffic Control Interface, centralized merging point: reduced protocol overhead, policy enforcement) • Quantized heterogeneity model: supports scalability (VC space, data duplication) and layered flows • Very large clouds: need to setup multiple servers with SCSP coordination • Future work: interworking to Multilayer Routing clouds