The city of San Diego built its own content delivery network called REMNet to deliver live cable broadcasts and surveillance video over IP. REMNet uses Network Appliance caches and Cisco routers to deliver up to 200Mbps to 10,000 nodes. It streams 200 simultaneous videos to the public and provides training videos for city workers. The network has increased public access to meetings and saves money compared to outsourcing video streaming.
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San Diego taps IP network for video delivery
By Jason Meserve
Network World, 03/25/02
The image of not-so-Web-savvy government, particularly at the local level, is being turned on its ear by
the city of San Diego's video-over-IP network that delivers live cable broadcasts to Internet users and
internal surveillance video to the local law enforcement community.
San Diego is in the process of building its own content delivery network using Network Appliance
caches and Cisco routers and switches, all connected by a high-speed backbone, serving about 10,000
nodes. The network, known as REMNet (Reliable, expandable management network), delivers up to
200M bit/sec to the desktop, more than enough for delivering good-quality video to each user that
requests it. It also uses caches outside the firewall to better serve San Diego residents.
Still in development, the network already is serving 200 simultaneous streams to the public via the
Internet at all times, says Allen Myers, chief networking architect for San Diego Data Processing Corp.
(SDDPC), the 300-person IT arm for the city. The programming content originates from the city's cable
head-end and is served in Windows Media and RealNetworks format, both at 100K and 56K bit/sec.
Most of the content is city promotional information and government-related meetings such as city
council sessions and mayoral addresses.
Content is available 24 hours a day, seven days a week - a big increase over four or five council sessions
the city offered previously when it used a service provider to encode and serve the streaming media to
the Internet. Each session broadcast over the Internet cost the city between $4,000 and $5,000.
"It was costing us significant money for a few hours of streaming video," Myers says. "In our first year
[of serving internally], our return on investment is basically even, since the cost of the equipment is the
about the same as what it cost us to outsource just city council sessions, but now we can do 24-7 video."
Raw video is encoded at the cable head-end using StreamFactory and StreamGenie from Pinnacle
Systems. The software runs on a specialized multiprocessor box and can create both the Real and
Microsoft streams simultaneously, Myers says. Network Appliance's ContentDirector and F85 filer
content storage products are used to push the video through the firewall to a Network Appliance's
NetCache C1100 streaming media cache for public consumption. This lets SDDPC keep public access
outside the city network.
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2. Caching content
Internally, Myers is deploying caches to roughly a dozen major city offices so internal video on-demand
content can be retrieved locally, saving bandwidth on the WAN that connects city offices. (The WAN
consists of some ATM connections but is being migrated to Gigabit Ethernet.) A combination of
multicast and unicast technology is used to maximize the use of bandwidth when pushing and service
video on the internal network. Once the major locations have caches installed, Myers hopes to drop
caches into smaller police and fire stations.
In addition to streaming more video and using the internal network resources more efficiently, one of the
project's goals is to deliver training videos over the city intranet. Police, fire and other city workers
could watch the training from their own buildings, with the streams delivered from a local cache.
City officials still have to work out operational issues that are impeding that goal. Myers says
procedures have to be developed for who manages the training materials and ensures all the caches have
the most up-to-date content.
Though not fully utilized for training on demand, San Diego's IP network is being used for some video
surveillance applications involving proprietary and standards-based technology.
"We're doing different types of monitoring - some security-related, some more operational," Myers says.
Though he couldn't go into detail, he says the monitoring technology is "real strategic stuff" and
involves local, state and federal offices located in the greater San Diego area.
Wireless visions
Myers envisions using wireless technologies to deliver video of a building to a police officer's PDA so
he can view the premises he's about to enter.
SDDPC hopes to migrate its voice network to IP as well. Myers says the network is capable of voice
over IP in some locations, but the city is still in the proof-of-concept phase. To move forward, more of
the legacy network equipment needs to be modernized.
The new network has paid dividends. Under the old outsource system, the city received only about 800
hits per month to its video feeds. Today, it's nearly triple that - about 2,100 to 2,500 hits per month.
City councilors are creating individual portals to deliver messages to constituents in their districts. Also,
Myers says the city is videotaping miles of sewer system, with the video stores on the network for
reference purposes in case something happens to a line.
Online even trumped cable TV: During the recent mayoral address, the cable television feed had some
technical glitches while the Internet video performed flawlessly.
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