SDN Controllers in the Broadcast TV Environment

Transcription

1 SDN Controllers in the Broadcast TV Environment Julian

2 Agenda Broadcast TV use-cases in the WAN How resilience is achieved The role of the SDN Controller

3 Broadcast TV in WAN Distribution From HQ to DTTV transmitter masts and satellite head-ends Compressed: few 10 s of Mbps per stream Contribution e.g. from sports stadium to HQ Produced on-the-fly in Outside Broadcast (OB) truck and then transported over WAN to HQ In past, typically compressed but now some broadcasters moving to uncompressed Remote Production (new) e.g. from sports stadium to HQ, or small remote studio to HQ Raw camera and audio feeds sent directly over WAN to production gallery in HQ Typically uncompressed

4 Uncompressed video bit-rates

5 SMPTE Seamless Protection Network Source Receiver Two duplicate streams sent simultaneously into network: Live-live RTP media streams with sequence numbers They follow diverse paths across network Receiving media device buffers streams and inspects RTP sequence number of packets if packet with sequence number N is missing from one stream, is replaced by corresponding packet from other stream

6 Path Diversity in WAN Could build network with two distinct planes, and send duplicate streams over the two planes However, sparse fibre networks (rings) and fate-sharing make it difficult to build disjoint dual plane networks in many cases Therefore in practice typically have single-plane WAN network, with pairs of path-diverse TE LSPs to carry the SMPTE duplicate streams Typically RSVP-TE P2MP LSPs used, as most of the traffic is multicast Also used for Financial Market Data

7 Source PE1: ingress for red P2MP LSP PE2: ingress for blue P2MP LSP customer site D PE10 PE3 customer site A PE9 PE4 PE8 P1 P2 PE5 customer site C PE7 PE6 customer site B Each customer site is dual-homed to a pair of PEs: one PE is served by the red P2MP LSP, the other is served by the blue P2MP LSP.

8 Source PE1: ingress for red P2MP LSP PE2: ingress for blue P2MP LSP customer site D PE10 PE3 customer site A PE9 PE4 PE8 P1 P2 PE5 customer site C PE7 PE6 customer site B If any node or link breaks, each site is still served by at least one P2MP LSP, so no interruption to service

9 BGP Multicast VPN Provides isolation between different customers that use the network => Multitenancy PE1 Each customer gets its own dedicated P2MP LSPs Same VPN can carry both unicast and multicast traffic. Extranet functionality to allowed controlled exchange of data between desired VPNs. PE5 PE4 PE3 PE2

10 BGP Multicast VPN: Selective tree Source: S1, G1 S1, G1 --> P2MP X Broadcast TV has highbandwidth streams PE1 So each stream put onto its own Selective Tree that only goes to PEs with interested receiver PE5 P2MP LSP X PE2 PE4 PE3 Receiver 1: S1, G1 Receiver 2: S1, G1

11 SDN Controller for WAN Requests via GUI Requests via Northbound API Real-time topology (BGP-LS) LSP reporting (PCEP) Streaming Telemetry NorthStar Controller LSP creation/modification (PCEP) MPLS Network

12 The Role of the SDN Controller in Broadcast TV Live visibility of network topology, SRLGs and bandwidth availability Path computation and instantiation of point-to-point and P2MP LSPs Including diversely routed pairs of LSPs Path diversity is required by SMPTE Seamless Protection scheme Path computation takes bandwidth requirement of media stream into account contention is unacceptable! Monitoring of live LSP status Consumption and visualization of streaming telemetry Bandwidth calendaring Exhaustive failure simulation as a function of time, taking into account the bookings on the calendar

13 Media flow instantiation via SDN Controller OSS P2MP LSP ingress/egress nodes (S,G) MVPN identity BW requirement Instantiation by PCEP Start/end time REST API Status reporting via PCEP SDN Controller

14 PCEP instantiation of P2MP LSP and VPN/(S,G) binding Key PCEP drafts: IETF draft for PCE-initiated P2MP LSPs PCEP PCInitiate message carries full ERO of each sub-lsp IETF draft for carrying flow-mapping information Draft has TLV to carry Route Distinguisher of the MVPN Also has TLVs for multicast source and group address, when using Selective Trees These TLVs included in the PCInitiate message when instantiating the P2MP LSP

15 Multicast Flow Specification TLV Encoding Rsvd S W R Rsvd B Z Src Mask Len Grp Mask Len ~ Source Address ~ ~ Group multicast Address ~

16 NorthStar live demo Come and see live demos of our NorthStar WAN SDN Controller at the Juniper exhibition booth

17 Thank you