Sunday, July 24, 2016
What's the difference between Access Levels and Access Areas?
Access Areas are enclosed parts of the site where access is controlled by a Keypad, Card Reader, or Single Door Module. This will include the Default area (commonly called 'On-site'), which is the entire site enclosed by the fence and accessed through a gate or main door. It will also include any building where the door access is controlled by an access device, any floor accessed by an elevator keypad, and any gated or walled area within the property controlled by an access device. Access areas do NOT include individually alarmed units, alarmed office areas, or any other part of the site that does not have individual access-controlled doors or gates to enter.
Access Levels combine Access Areas and Time Schedules to control access for groups of users. This allows a site to easily issue access to a user by assigning them into a specific, pre-defined Access Level, without having to select new access privileges each time a new user is entered.
After you have set up Access Areas and Time Schedules for a site, you create access levels that combine both. Most sites only have 2 - 3 Access Levels for the site:
· One Access Level for customers who are limited to business hours and to areas that are considered 'On-site'.
· One Access Level for customers that have 24-hour access to 'On-site' areas of the site.
· One Access Level for employees that have 24-hour access to all parts of the facility.
· Customers who have 'extended hours' (such as 6:00 am - 10:00 pm) and have access to 'On-site' areas of the facility.
· If the site has individual buildings that are keypad-controlled, a separate access level could be set up for each building with the allowed hours for that building.
· Employees can have separate access levels by shift and areas that they are allowed into.
Saturday, July 9, 2016
Bandwidth Basics for IP CCTV Design
When using IP cameras, Megapixel cameras, NVRs or even DVRs, understanding the basics about how much bandwidth is available and how much is needed is critical in planning, designing and deploying IP video surveillance systems. Copper Ethernet wiring (typically Cat-5, Cat-5e, Cat-6 or Cat-7) have a practical length limitation of 100 meters (or about 300 feet) between devices. To accommodate longer-length wired network connections, fiber can be used.
This article is focused for a non-IT audience such as security managers, electronic technicians, sales and marketing folks.
How Much Bandwidth is Available?
To figure out how much bandwidth is available, you first need to determine what locations you are communicating between. Much like driving, you will have a starting point and destination. For example, from your branch office to your headquarters. However, unlike driving, the amount of bandwidth available can range dramatically depending on where you are going.
The most important factor in determining how much bandwidth is available is whether or not you need connectivity between two different buildings.
In the Same Building: 70Mb/s to 700 Mb/s of bandwidth is generally available
In Different Buildings: .5 Mb/s to 5 Mb/s of bandwidth is generally available
The amount of bandwidth available going from your office to a co-worker's office in the same building can be 200 times more than the bandwidth from your office to a branch office down the block.
This is true in 90% or more cases. Note the following exceptions:
If these are different buildings but on the same campus, more bandwidth may be available.
If you are in a central business district of a major city, more bandwidth may be available.
If you are a telecommunications or research company, more bandwidth may be available.
The key driver in bandwidth availability is the cost increase of deploying networks between buildings. Generally referred to as the Wide Area Network or WAN, this type of bandwidth is usually provided by telecommunications companies. One common example is cable modem or DSL, which can provide anywhere from 0.5 Mb/s to 5 Mb/s at Rs. 3000 to Rs. 5000 per month. Another example is a T1, which provides 1.5Mb/s for about Rs. 8000 to Rs. 16000 per month. Above this level, bandwidth generally becomes very expensive.
Many talk about fiber but fiber to the building is not and will not be widely available for years. Fiber to the home or to the business promises to reduce the cost of bandwidth significantly. It is very expensive to deploy and despite excited discussions for the last decade or more, progress remains slow.
By contrast, bandwidth inside of buildings (or campuses) is quite high because the costs of deploying it are quite low. Non technical users can easily set up a 1000Mb/s networks inside a building (aka Local Area Networks or LANs) for low installation cost with no monthly costs. The cost of deploying networks in buildings are low because there are minimal to no construction expenses. When you are building a network across a city, you need to get rights of ways, trench, install on telephone poles, etc. These are massive projects that can easily demand millions or billions of dollars in up front expenses. By contrast, inside a building, the cables can often by quickly and simply fished through ceilings (not the professional way to do it but the way many people do it in deployments).
A lot of discussion about wireless (WiMax, WiFi, 3G, 4G etc) exists but wireless will not provide significantly greater bandwidth nor significantly better costs than DSL or cable modem. As such, wireless will not solve the expense and limitations of bandwidth between buildings. That being said, wireless absolutely has benefits for mobility purposes and connecting to remote locations that DSL or cable modem cannot cost effectively serve. The point here is simply that it will not solve the problem of bandwidth between buildings being much more expensive than bandwidth inside of buildings.
How Much Bandwidth Do IP Cameras Consume?
For the bandwidth consumption of an IP camera, use 1 Mb/s as a rough rule of thumb. Now, there are many factors that affect total bandwidth consumption. You can certainly stream an IP camera as low as 0.2 Mb/s (or 200 Kb/s) and others as high as 6 Mb/s. The more resolution and greater frame rate you want, the more bandwidth will be used. The more efficient the CODEC you use, the less bandwidth will be used.
For the bandwidth consumption of a Megapixel camera, use 5 Mb/s to 10 Mb/s as a rough rule of thumb. Again, there are a number of factors that affect total bandwidth consumption. A 1.3MP camera at 1FPS can consume as little as 0.8 Mb/s (or 800 Kb/s) yet a 5 megapixel camera can consume as much as 45 Mb/s.
What Does this Mean for my IP Video System?
Just like dealing with personal finance, we can now figure out what we can 'afford':
Between Buildings: We have 0.5 Mb/s to 5 Mb/s to 'spend'
Inside Buildings: We have 70 Mb/s to 700 Mb/s to 'spend'
IP cameras: Cost us 1 Mb/s each
Megapixel cameras: Cost us 5 Mb/s to 10 Mb/s each
Using these points, we can quickly see what combination of IP and megapixel cameras we can use between buildings or inside of buildings.
Inside of buildings, it is easy to stream numerous IP and megapixel cameras.
Between buildings, it is almost impossible to stream numerous IP and megapixel cameras.
Because of this situation, the standard configuration one sees in IP Video systems is:
A local recorder at each building/remote site. The local recorder receives the streams from the building and stores them.
The local recorder only forwards the streams (live or recorded) off-site when a user specifically wants to view video. Rather than overloading the WAN network with unrealistic bandwidth demands all day long, bandwidth is only consumed when a user wants to watch. Generally, remote viewing is sporadic and IP video coexists nicely with the expensive Wide Area Network.
The local recorder has built-in features to reduce the bandwidth needed to stream video to remote clients. Most systems have the ability to reduce the frame rate of the live video stream or to dynamically reduce the video quality to ensure that the video system does not overload the network and that remote viewers can actually see what is going on the other side. Generally, the live video stream is sufficient to identify the basic threat. In any event, bandwidth is generally so costly, especially the upstream bandwidth needed to send to a remote viewer, that this is the best financial decision.
Friday, July 1, 2016
An Ethernet splitter can split a single Internet connection so that two or more computers can connect to the Internet simultaneously. It can also create additional connections for other computers on a network, which can reduce the overall amount of cabling required to setup a network. Unfortunately, Ethernet splitters cannot resolve the network collision issues that may occur if the computers connected to the splitter are using the same network resources simultaneously.
The CAT 5E Ethernet splitter allows two separate devices to share the same Ethernet cable. Ethernet splitters are generally used in pairs, with one CAT 5E splitter at the outlet and another Ethernet splitter at the patch panel. This allows for several wiring configurations to connect more devices to your network. Primus Cable offers both Ethernet splitter adapters and pigtail type Ethernet splitters.
Our phone cable is commonly used for 10Base-T and 100Base-T networking, particularly for telephone and low speed data applications. We stock both phone cable for plenum and for riser applications. If your project involves installation in plenums or air spaces, the CAT 3 Bulk Cable, Plenum CMP Solid UTP 25Pair 24AWG, 1000, White is a wise choice.
This phone cable features 25 unshielded solid copper pairs in a 24 AWG diameter cable. This phone cable is ideal for indoor voice communications applications, and is supplied on a wooden spool. This CAT 3 phone cable is also easy to install with its color striped pairs.
Primus Cable provides a wide assortment of networking and telco tools for your installation project. EZ-RJPRO™ HD Ratchet Crimp Tool is the professionals’ choice when working with CAT 5E and CAT 6 RJ45 connectors. It also works well with EZ-RJ12/RJ11 connectors. This crimping tool functions as a wire cutter, stripper, and crimping tool all in one. The ratcheted straight action crimping motion ensures a uniform crimp every cycle. Features precision cast crimping dies for superior accuracy.
How to Connect an Ethernet Splitter
– Insert one end of the Ethernet splitter into the primary Ethernet port of the device that is providing the network connection (such as the cable/DSL modem or Internet router).
– Insert the Ethernet cables from the devices to be connected (such as a computer, printer, or scanner) into the Ethernet splitter. Users often connect a printer and computer to the splitter in order to minimize the frequency with which network collisions occur while sharing the connection.
– Test the connection of the devices on the splitter to ensure that they can connect to network resources.
How to Make an Ethernet Splitter
– Procure the following materials: a short Ethernet cable, 2 x RJ45 keystone jacks, electrical tape, super glue, and crimp tool.
– Crimp one end of the Ethernet cable so that the wire’s ends are visible. Leave the other end of the cable in-tact.
– Follow the directions that come with the keystone jacks to open them, then place the wires from the Ethernet cable into the jacks to split the connection. Place the white and orange wires into Pin #1, the orange wire into Pin #2, the white and green wires into Pin #3, and the green wire into Pin #6. On the second keystone jack, place the white and blue wires into Pin #1, the blue wire into Pin #2, the white and brown wires into Pin #3, and the brown wire into Pin #6.
– Glue the jacks to each other by the sides with super glue, then snap them together.
– Wrap electrical tape around any exposed wires and begin using the new Ethernet splitter.
This diagram works in a half duplex mode which provides communication in both directions, but only one direction at a time. Under normal operation, each port is constantly sensing any traffic through its receiving pair of wire. As long as it can sense that data is being processed, it will not start sending data. The significance of this operation is to avoid collision where two ports are sending data at the same time, and due to this phenomenon, data will be discarded. When this issue is resolved by both computers, they will start to transmit at random amount of time. The circuit employs the method known as Carrier Sense Multiple Access / Collision Detecion (/CD) wherein it allows the devices to take turns using the signal carrier line. In this operation, the hub’s primary task is to allow each port to check the signal level of the line to determine whether someone is already using it. The device waits for a few seconds if it is in use, or it transmits otherwise.