SISAT
University of Wollongong
ISIT925_2016
Major Project
(This activity is worth 20% of your final mark)
This is a group project that requires participation from all members of the group.
Individual marks may be adjusted to reflect your contribution relative to others.
Channel4
Channel4 is an Australian free-to-air television broadcaster that delivers 4 digital channels of video content into the Sydney and Melbourne metro markets. With the massive changes in the media landscape in the past five years, Channel 4’s management realizes that it must move to make their operations more cost-effective so as that more money can be spent making quality content that will increase ratings and thus advertising revenue streams.
Consultancy company, Bradley, Sturgiss and Wright (BSW), was commissioned to undertake a review into Channel4’s operations in a bid to increase their profitability. One of the key findings was that:
“Significant savings could be made by removing duplicated networks and moving to a converged IP environment, based on commodity hardware and skills”.
Your role is to analyse the current network and business requirements to propose a new reference architecture using the methodology learned in ISIT925. The level of detail in the reference architecture should be sufficient for inclusion in a tendering document that companies can use to submit competitive bids to under take final design and installation.
Background
Since the mid-2000’s the profitability of broadcast television has dropped dramatically. This is due, in part, to ‘new media’ and the four-fold increase in free-to-air television channels, which have fragmented audiences. In addition, the rise of peer-to-peer sharing (such as bit-torrent) has changed audience viewing habits as viewers now expect to watch content as soon as it premieres overseas or alternately in bulk at times that suit them.
With approximately two thirds of all Channel4’s content is sourced from the US and other overseas content produces, piracy is having an increasing impact on their ratings. However, another key finding of the BSW report was that
“Local and ‘Australian Made’ content premiering in Australia during prime-time is relatively immune to piracy. This is especially true of Channel4’s target demographics and an increase in quality content of this type will increase profitability”
Thus Channel4 is looking to spend savings gained from operational efficiencies on local coproductions between Channel4 and independent producers.
Channel4 operates four free-to-air television channels (Channel4, C4forKids, WOW and
QTV). However Channel4 outsources all its playout capabilities to MediaHub and all its Terrestrial DVB Transmission to BroadcastAustralia which has regularized and reduced their day-to-day operating costs.
Finally, BWS also recommended that all SAP, Scheduling, Records Management be moved to a Cloud provider which will reduce the cost of these systems, as well as increase redundancy and uptime. While the logistics of this migration are beyond the scope of this project, Management have requested that ongoing data-requirements of this should be factored into your design.
Summary of Requirements
The broad requirement delivered to you by Channel4 management is to analysis the network and design a network specification that can then be validated by BSW who will then provide management with recommendations about whether this design will increase operational efficiency and overall profitability based on their return on investment (ROE) calculations. If so, your reference architecture will become the basis of a tender specification by which the private sector will propose a final design specification
In addition Management wishes the following requirements to be taken into consideration in your design;
• Decommission broadcast routers and the SDI and ASI Networks.
• Replace decommissioned broadcast routers with SDI over IP • Securely isolate broadcast IP Traffic from Internet and corporate traffic.
• Provide QoS plan to ensure SLA’s are meet.
• Provide SLA’s that meet broadcast requirements.
• Include capacity in the network for cloud-based applications.
• Include capacity to monitor the network performance against SLAs
• Remove signal points of failure for critical systems.
• Reduce ongoing costs wherever possible.
Physical Environment
Channel4 runs two studios;
The Melbourne studio is the company’s head office, and contains the majority of staff and main production studios. The staff in the main office are distributed across five floors.
Department No. of Staff
Management 50
Human Resources 20
Legal 4
Melbourne Advertising Production 20
Melbourne Advertising Sales 20
Melbourne News 50
Technology (Engineering and Support) 30
Television Production 150
Television Scheduling and Digital Media Centre 30
Total Melbourne Staff 374
Table 1:Melbourne Staff Distribution
Sydney, by comparison, has a local news bureau and advertisement production and is much smaller. In Sydney, the staff are distributed across two floors.
Department No. of Staff
Sydney News 50
Advertising Sales Sydney 30
Advertising Production Sydney 30
Technology (Engineering and Support) 15
Total Sydney Staff 125
Table 2: Sydney Staff Distribution
Current Broadcast Environment
In order to understand the network requirement it’s essential to understand the broadcast workflow of Channel4. A diagram of the workflow described below is included as Figure 1. It should be noted that this flow is duplicated in both sites.
There are three types of video content that Channel4 uses; ExProd Content (Externally produced programs and advertisements), InProd Content (Internally produced programs and advertisements) and Live Content (Such as News and Sporting Events). Each of these types of content enters the broadcast network in different ways.
InProd Content is edited by Channel4 and the finished product is sent as SDI streams to be stored in the Digital Media Centre, via the Studio Router.
ExProd Content is provided to Channel4 on solid-state media as a digitized video file. These files are stored in the Digital Media Centre until required.
Both InProd and ExProd content is stored by the Digital Media Centre as files ready to played out as required over an SDI link to the studio router.
The studio router, takes SDI or ASI inputs and allows them to be assigned to many outputs simultaneously. This could an MPEG Encoder, Video Output, Satellite Uplink or Digital Video Network (DVN) line to Media Hub.
Channel4 runs three DVN lines to MediaHub which transmit MPEG encoded Video over an ASI stream. Generally, this is MPEG-encoded video either from the Digital Media Centre or live video from a News Studio. The link between Channel4 and the Media Hub is leased from the telecommunications carrier, Telstra.
With the exception of live video (which is played out immediately), MediaHub records the video sent via the DVN or Satellite backup to it server’s onsite, to be played out as per the schedule send to it by Channel4 for play-out.
Figure 1: Current Broadcast Network
Proposed Broadcast Flow
In order to reduce network duplication, it has been proposed that the SDI/ASI network and the Studio Routers be removed. The proposal is that all video streams should travel over the IP Network.
Figure 2: Conceptual Diagram of Converged Network
The proposed broadcast network utilizes the File Transport Protocol to send all “non-live” video to the MediaHub as files to be played out (see Table 1 for details)
File Type No. Per Day Average File Size
30 Sec Advertisement 30 9.5MB
45 Minute Program 50 1.2GB
90 Minute Movie 5 2.4GB
Table 3: Average MPEG-2 File Sizes
All live video would be sent as SDI over IP, using multicast-groups to reduce network traffic, while allowing multiple outputs to simultaneously receive the same video output. Channel 4 would like to be able to use up to twenty-five simultaneous SDI streams within the two Broadcast Centers and send three, between sites and out to MediaHub. This will remove Channel4’s reliance on SDI and ASI Networks, and save significant cost in Broadcast routers.
This requirement should be reflected in the design of your multicast address space, security policies, SLA’s and bandwidth planning.
Network Property SDI Requirement
Bandwidth 270Mbps
Latency 100ms
Jitter 30ms
Loss None
Table 4: SDI over IP Network Requirements
Existing Corporate Network
The existing corporate network was put in 10 years ago and all the existing hardware is out of support. While money had already been budgeted by management they now want to leverage this expenditure to replace their broadcast network as well.
As can be seen in Figure 3: Current Network Diagram, the network layout is currently quite simple. A modular “user access” switch is located on each floor and connected to the Distribution/Core switches with a 1Gbps uplink. Each of the two Distribution switches are connected to each other and to the site router by additional 1Gbps interlinks.
Cisco VoIP communications is provided in this arrangement and is anticipated to be reinstalled or updated in future network upgrades to include video for video-conferencing..
At each site the router, connects to the other site by a 1Mbps leased line and all Internet traffic exits Channel4 through the Internet connection in Melbourne.
Figure 3: Current Network Diagram
Corporate Network Applications
In addition general office traffic, the following applications have specific bandwidth, jitter, delay and loss requirements. Table 5, provides an insight into the bandwidth requirements of these applications. Currently these services are housed on servers in the server rooms at each site, but will be moved to the cloud in the future. For the purposes of this project, all calculations should include the future bandwidth requirements for planned cloud based services. The follow indicative information has been provided to us in these calculations.
As part of this upgrade the existing VoIP communications systems requires upgrade to include video conferencing capability.
The converged IP environment opens the way for monitoring of pre-production, production and broadcast content from the desktop. Explicit bandwidth must be factored into your design to ensure that latency of general and specialist corporate functions is not compromised through this new capability.
File Type File Sizes Average Time Users
SAP (ERP) 160KB ~15 sec Management,
Advertising Sales,
Television Production,
HR
HP TRIM (Document Mngt) 1-30MB ~ 1min All Staff – Except News
Scheduler 10KB ~ 2 sec Management and Scheduling
iNews 50KB ~ 5 sec News
Table 5: Average data requirements for corporate applications
As
Monitoring
Network monitoring is essential as the new converged network will be underlying infrastructure critical to both corporate and broadcast business goals. Channel4 currently uses the Zabbix platform for the monitoring of its network and SNMP compatible broadcast equipment. This platform has been found to be effective in monitoring critical infrastructure and upper management have requested that it continue to be used.
Upper management has also requested that Zabbix be setup to measure the performance of the network against agreed SLA’s. As part of this project you have been requested to propose a set of Network SLA’s along with early warning alert thresholds.
Specifically SLA’s should be created to measure the following critical services:
• Media Hub to Channel4 Link
• Sydney to Melbourne Channel4 Link
• Latency of corporate systems (see Table 5)
• Latency of Live Video Feed
Other Information
Channel 4 NAT all their traffic. Internal Range: 10.0.0.0/8
External Range: 203.2.225.0/24
Revision
History
Revision No. Date Change
Draft 1.0 26 August 2014
Final 2 September 2014
1.0 30 September 2014 Figure 2 altered - ExProd
Sentence added on p. 3: The link between Channel4 and the Media Hub is leased from the telecommunications carrier, Telstra.
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