UKERNA CDI TrialInfrastructure for Content Delivery

Steve WilliamsUniversity of Wales Swansea

Focus on issues in deployment now…

but keep the vision in mind.

Previously on streaming…

• Commercial sector– Cable TV– Video on Demand, live broadcast– Dedicated, secure, purpose built networks

• Academic sector– Local distribution of local and other content– Distribution splitting of live content (SURFNet 2500

viewers)– No caching of on-demand content– Multi-service, multi-purpose, multi-administrative-

domain networks– Some commercial providers just don’t get it!

Design and deploy an extensible, standards-based architecture that is scaleable to the needs of the

UK academic community

Scaleability

• 10 Gigabit SJ4 & GÉANT– 1500 high quality video streams (7Mbps MPEG-

2)– Coleg Gwent has 30,000 students!

• SJ4 now connects HE, FE and Schools – how many…– close your eyes and think of a big number – dark isn’t it – All want video – yesterday!– Access-link limitations (FE-England 2Mbps)

• Server farms not enough– Content is never where you want / expect it to be– Need to use network resources efficiently

Transport options

• Multicast– Yeah, right! I really do wish…

• Simulated / partial multicast / unicast– Proxy-based live-stream splitting– Proxy-based on-demand caches

Server farm

Institution proxyand cache

Clients

SJ4

Software

• Kasenna Mediabase XMP SE– Running on IRIX and Linux– Commercial CDNetworks, on-demand & live cable-nets

via set-top boxes etc (e.g. Kamas, Utah…)– Prefix caching

• Real Networks– Helix Universal Internet Server– Helix Universal Gateway– Running on Linux

• Monitoring– Cisco SAA– mySQL & scripts

Hardware

• Core– SGI Origin 300 + TP900 storage pack– Dell 2950

• Edges– Sun LX50 (3 x 70GB)– Dell 2900 (6 x 73GB)– Origin 300 + TP900

• 1.5 Terabytes content storage available• Monitoring

– Cisco 805 / 7206

Deployment issues

• Use MPEG-2 and MPEG-4• Mediabase now only supports one MPEG-2 plugin• So use MPEG-4 only… (seen as the future by most)• Issues in caching MPEG4 on Mediabase

– Caching does not work at all in XMP SE (bug fix soon?)

– MPEG 4 seen as the future for most CD across Europe

• Caching MPEG2– Realtime mode only– Prefix caching works

Hosting Server

• Scaled to suit distribution model– Processor– Network– IO throughput– Disk size– O/S– Licensing may affect choices (per server – per

site)

Network requirements

• Depends on distribution model• To QoS or not to QoS…• Videoconferencing metrics

– Packet loss < 0.25%– Jitter < 30ms– Latency (OWD) < 50ms

• Videoconferencing traffic profile…

Example of 384 Kbps Video (30 fps) Conferencing Traffic (CIF)

• “I” frame is a full sample of the video• “P” and “B” frames use quantization via motion vectors

and prediction algorithms

“P” and “B” Frames128–256 Bytes

“I” Frame1024-1518

Bytes

“I” Frame1024-1518

Bytes

15pps

30pps

600Kbps

32Kbps

• Streaming metrics– Packet loss – critical for some CODECs– Latency & jitter – much less critical– Need to quantify

• Streaming traffic profile…

Streaming bandwidth

Streaming bandwidth - 350Kbs

0200400600800

1000120014001600

1 3 5 7 9 11 13 15 17 19

seconds

Kbps

…

• QoS– Impact of applying QoS AF-PHB on an

aggregated tcp / udp transfer stream– Sizing the AF bandwidth– tcp backoff under congestion within the

aggregate

Where are we now…

Kasenna Mediabase XMP

SE in Reading C-PoP

Quicktime ClientsDirect Delivery from Mediabase

Kasenna Mediabase XMP

SE inReading C-PoP

Kasenna MediabaseXMP SE atInstitutions

Quicktime Clients

SJ4

Proxy / Cache Delivery from mediabase

Helix Universal Internet Server

Helix UniversalGateway

Quicktime & RealMedia Clients

SJ4

Proxy / cache delivery from Helix

SJ4

Monitoring the netmySQL server

Cisco SAA

Cisco SAA

Cisco SAA

Cisco SAA

Cisco SAA

Cisco SAA

Cisco SAA

Web server

Don’t forget the user interface…

Steve WilliamsUniversity of Wales Swansea

s.r.williams@swansea.ac.uk