Multimedia over DSL By Phil Moy
May 14, Agenda n DSL Forum Working Text 80 - Multiservice Architecture & Framework Requirements n DSL Forum Working Text 81 - Architecture Requirements for the Support of QOS Enabled IP Services n BRAS (Broadband Remote Access Server) – Packet Processing – Differentiated Services n Current Industry Trends
May 14, Central Office Wiring Center BRAS Architecture Overview ATM ATM DSLAMs RT DSLAMs MTU DSLAMs Communications Portal Storage Applications (eg, VPN) ISPs / Internet L3 Switch /IPSS Voice Gateway ATM or Ethernet PSTN Class 5 BRAS Video Server
May 14, WT-080 Multiservice Architecture & Framework Requirements n IP QOS – Guaranteed QOS n ATM CAC (Call Admission Control) CBR VBR n RSVP reservation n Bandwidth On Demand, “Turbo Button” – DSL Trained to maximum, allows dynamic control of rate n Many To Many Access n Content Distribution – Caching – IP Multicasting
May 14, WT-080 Multiservice Architecture & Framework Requirements (cont) n Bandwidth – ADSL - 8 Mbps up to 10,000 feet – ADSL2 - will provide 8 Mbps with a longer range – ADSL2+ - doubles the bandwidth over ADSL but with half the range – VDSL Mbps at 1000 ft, Mbps at 4500 ft
May 14, WT-081 DSL Evolution - Architecture Requirements for the Support of QOS Enabled IP Services n Many to Many supported by TVR (Transparent Virtual Routing) n QOS - Diffserv – DSCP Marking of IP Header TOS Byte (6 bits) n AF - Assured Forwarding n EF - Expedited Forwarding n BE - Best Effort n Hierarchical Scheduling – Schedule Traffic Downstream taking into account all physical links to subscriber n Fragmentation – Fragment Low Priority Packets to minimize delay/jitter
May 14, BRAS: Packet Processing Cells... Cell, PPP frame, PPPoE frame, L2TP frame, Ethernet frame, IP datagram Header Per VC decision: Ingress Egress SAR Mask Relevant Bits Integrated Forwarding/ Scheduling Process n Diff Serv Classification n Best Effort n Expedited Forwarding n Metering n Priority Scheduling SAR AAL2 PPPoE IP Gaming IP Video
May 14, BRAS: Differentiated Services DS3 DSL OC-3 ATM WAN BRAS Switch CPE Router with NAT, or Ethernet Modem, or IAD Best effort to Serv Provider 1 Guaranteed to Serv Provider 1 Best effort to Serv Provider 2 Voice over IP Aggregation Group 3 Aggregation Group 2 New gaming service One VC serves multiple subscribers ATM QoS thru backbone Policies determine which subscribers can access service IP DiffServ CoS mapped to ATM QoS Aggregation Group 1 (IP) Video Server
May 14, Demo System
May 14, Current Industry Trends n BRAS space is new with products developed from Alcatel, Cisco, Copper Mountain, Juniper, and Redback n RFPs for BRAS currently out from ILECs with scheduled roll out as early as 4th quarter 2003 but probably next year
May 14, Acknowledgments n Copper Mountain Networks n DSL Forum
May 14, Conclusion n BRAS Architecture enables Multimedia over DSL – BRAS allows multimedia over “Dumb” DSLAMs. – Congestion usually only found in the last mile can now be avoided – Turbo Button allows video on demand by dynamically boosting bandwidth up when a user purchases a movie – Diffserv allows high priority multimedia traffic to coexist with low priority web traffic. n Questions?