Video Surveillance

Published on February 2017 | Categories: Documents | Downloads: 69 | Comments: 0 | Views: 620
of 2
Download PDF   Embed   Report

Comments

Content

Q&A | Video Surveillance
Q: What are the benefits of IP Video
Surveillance?

Q: If the network goes down, how do
we ensure that our cameras stay live?

In the old CCTV world, monitoring stations
were fixed and hardwired; now they can
be flexible and mobile. IP video systems
are easy to install and are flexible to
meet changing requirements. IP Video
Surveillance systems are able to easily
combine multiple locations to a single
video security solution and can integrate
to other security systems as part of a
complete holistic security framework. The
change to IP-based video surveillance has
coincided with dramatic improvements in
camera technology and the adoption of
high definition video for surveillance use.
High definition video not only improves the
quality of the image but it also means that
in many cases fewer cameras are needed
for a particular coverage area.

First, make sure that the edge power-overEthernet switches are properly protected
with uninterruptible power supplies.
Without this protection, even a small
power interruption produces a significant
interruption in video surveillance. All the
normal techniques for providing reliable
network connectivity apply to IP video
surveillance. We can also strategically
place the NVR servers in the network to
provide continued service if particular
network elements fail. Distributed video
storage provides both improved uptime for
network failures and reduces bandwidth
requirement. For the ultimate in video
surveillance up-time, cameras are available
with the ability to locally store video for
future retrieval. Combine this with a local
battery backup for the camera and you can
ensure complete recording even if the local
cable is cut.

Q: How much bandwidth will it require
from my network?
The bandwidth requirement for any
particular video stream is related to the
quality and complexity of the image, and
this can be configured to provide the right
balance between bandwidth cost and video
clarity. Good quality IP cameras can be
configured to provide compressed video
streams from less than 30Kbps up to
4Mbps (and more). A rough “rule of thumb”
number: 200kbps is reasonable for standard
definition and 1Mbps provides an excellent
quality high-definition stream. Don’t forget
to consider the aggregate bandwidth usage
for all hops on the network, as well as the
bandwidth required for monitoring stations.

Q: Can the cameras be centrally
managed if we have a multi-site
deployment?
Yes. Ease of management and flexibility
for multi-site deployment are key benefits
to IP Video Surveillance. The fact that all
three key elements (cameras, recording
systems and monitoring stations) are on an
IP network that can be securely accessed
from anywhere for management means
that administrators and technicians no
longer need to be on-site to manage the
systems. Furthermore, Video Management
Systems (VMS) are able to provide an overlay solution to complement the individual
components and provide a single integrated
system, not just for system management,
but for security operations too.

Q: How do you set up a multisite deployment and manage it
holistically?
Proper selection and implementation of
the VMS simplifies management of the
system with features like central access
control, storage allocation tools and archive
rules. These systems can also enhance
the operational value of the system though
integration to mapping and physical
security management systems, video
wall management, investigation tools and
automated event handling.

Q: Can you talk about the tradeoffs
when it comes to unicast routing
versus multicast routing for IP video
surveillance?
The tradeoff is bandwidth efficiency versus
network administration complexity. This
balance is currently shifting because new
IP network solutions are dramatically
simplifying network configuration for
multicast deployment. Although multicast
technology has been available for a
long time it is not widely used because
adding more bandwidth has been seen
as a simpler and more reliable alternative,
and before IP video there were not many
bandwidth-hungry applications that would
benefit from IP multicast. IP Multicast has
the ability to reduce bandwidth requirements by providing a single data stream
that is accessed by multiple devices. It is
particularly useful for IP video surveillance
when an organization has multiple
monitoring stations on a multi-site system.

Q&A | Video Surveillance

Q: How can I ensure that my video
streams come in real-time from my
remote monitoring stations?
Any application that needs real-time data
should use a network that is configured for
Quality-of-Service (QoS). Quality of service is
a collection of network techniques used to
ensure that the network provides particular
applications (in this case video surveillance)
with the end-to-end performance needed
by the application. The performance of the
network is measured in terms of packet
latency (how much time a packet of data
takes to traverse the network), packet jitter
(how much this latency varies over time)
and packet loss (how many packets don’t
make it to the destination). The actual
value for latency is not that important, but
keeping packet loss low is critical. One
of the drawbacks of the compression
algorithms used to compress the raw video
stream data to a manageable bandwidth is
that relatively low packet loss can produce
a dramatic drop in video quality. So the
question is not so much about real-time
delivery to the monitoring stations, but
about providing good quality video to the
monitoring stations. The answer is the
same: use QoS on the network.

Q: Do I need a dedicated network for
IP video surveillance? What are the
performance, scaling and security
issues if I utilize my existing IT
network?
There is a great parallel between IP
telephones and IP video surveillance in this
regard. Early IP telephone deployments
were often deployed on a separate network
but now it is completely commonplace to
run IP telephones on the normal IT network.
The same is true of IP video surveillance,
although the trend is several years behind.
Knowing that video can be a high-bandwidth application, many organizations
are still not prepared to let that additional

traffic on the IT network for fear that it will
slow down other applications. However,
the prevalence of gigabit and multi-gigabit
networks with high throughput switches and
routers means that many existing networks
are capable of supporting the additional
load of video surveillance systems. Qualityof-Service (QoS) must be implemented on a
shared network to maintain performance for
the video surveillance system.

Q: How can I secure my video streams
if I put video surveillance over my
existing IT network?
The security of the video surveillance
data as it travels over the network can be
maintained through typical network security
methods. Just how these are used depends
on the level of security required. Cameras
have multi-level username and password
authentication with IP address filtering
to stop unauthorized access. Video data
streams can use HTTPS to provide both
data encryption and protection from manin-the-middle connection attacks. The video
network itself can be logically separated
from the user network and firewalled off to
further prevent unauthorized access. Also,
the cameras can use 802.1X to authenticate
with the network. This prevents anyone from
using the camera’s network connection,
which may be outside the physical security
boundary of the facility, to get unauthorized
access to the network.

Q: How do I design the access portion
of my network to eliminate single
points of failure for cameras as well
as VMSs?
The discussion of reliability for IP video
surveillance systems again highlights the
flexibility unlocked by using an IP-based
system. All the technologies available to
provide reliable data networks, servers
and storage can be used by the IP video

Meridian IT Inc. is a member of Meridian Group International, a collection of
companies engaged in technology and equipment leasing businesses. Since 1979,
Meridian Group has been helping organizations optimize the strategic value of
their IT investments. Learn more at www.onlinemeridian.com
Nine Parkway North, Suite 500 / Deerfield, IL 60015 USA / Tel. 847.964.2664
www.meridianitinc.com

surveillance system to improve reliability
and uptime. Networks with dual uplinks,
switches with redundant power and
supervisor modules, Dual NICs, RAID disk
arrays and so on, all contribute to the
robustness of the system. Best practice
for the access edge where the cameras
connect is to use two stacked PoE switches
with multiple core links and pairs of
cameras with overlapping coverage of key
areas. And while thinking about system
uptime, do not ignore the value of a properly
implemented network management system
to keep the network running smoothly.

About Jim Emerson
With over 25
years of industry
experience in multiple
communications and
network technologies,
Jim provides
consulting, design and
operational expertise
to many Fortune 50
companies. Jim has been with Meridian IT
for almost three years and has a degree in
Applied Physics from Durham University.

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close