Access Networks practice Moldovn Istvn Dimensioning IPTV - PowerPoint PPT Presentation

Access Networks – practice Moldován István

Dimensioning  IPTV • Streaming: multicast – Bandwidth demand = channel * video rate • VoD: unicast – Bandwidth demand = estimated # of users watching* video rate  VoIP • Call bandwidth demand : codec dependent data + header overhead • Bandwidth demand = estimated # of simultaneous calls (Erlang) * call bandwidth demand  HSI • Premium service: the sum of reserved bandwidth • Best Effort Internet: different methods to estimate • Strategy: 50% on links should be reserved for Best Effort – Drop in case of congestion Tutorial Access Architecture — 2

Mac Forced Forwarding  DSLAM only sends to BNG • All other dropped  Operation: • PPP: sends to BRAS only • IPoE: – ARP request results in BNG address always – Packets sent to other destinations dropped • Can also be done with VLANs Tutorial Access Architecture — 3

QoS support  Priority based on 802.1Q VLAN tag • 3 bit = 8 classes  The priority bits described in 802.1p • VLAN priority and IP TOS are similar • Not all switches support 8 classes P-bits VLAN ID 802.1p CFI (3 bit) (1 bit) (12 bit) 802.1Q VLAN TAG • P-bits are in VLAN header, but not associated to the ID Tutorial Access Architecture — 4

Technology and planning  Spanning Tree restrictions  Traffic management • Traffic identification • Addressing • mapping  QoS  Protection Tutorial Access Architecture — 5 5

Spanning Tree STB Forrás DSL Video Video Server RGW DSLAM BNG SoftSwitch PBX Voice STB Internet BRAS Coax RGW HSI Where is the root? Traffic engineering? Tutorial Access Architecture — 6 6

 Thank you for your attention! • Questions? Tutorial Access Architecture — 7