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POE Q&A

Q1. Can multiple switches be used with our system? For example, if a customer has 2 buildings and other cameras are connected to other switches on the same network.

Answer:

Multiple switches can be used with the system.

The main requirements for a working PoE system are

  1. The hub and all cameras must be on the same subnet.
  2. All cameras should have connectivity over the network with the hub.
  3. The hub should have connectivity over the cloud with LSC.
  4. The upstream bandwidth requirements are fulfilled (please see Table 1).

What is the Meaning of 'On the Same Subnet'?

When two devices are on the same subnet, it means that their IP addresses are part of the same subnet i.e. their IP addresses are part of the same range of IP addresses.

 

What is an IP Address?

Just as names identify people and addresses identify houses and other types of buildings, IP addresses identify computers and other devices such as routers, laptops, and tablets on computer networks.

 

What does an IP Address Look Like?

An IP address is a string of numbers separated by periods and looks like 192.168.10.20.

Computers/devices on the same subnet can communicate with each other when connected through an Ethernet switch.

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Figure 1: Communication through an Ethernet switch

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Figure 2: Computers on the same subnet.

 

No two devices on an IP network should have the same IP address.

Computers and other network devices on different subnets can communicate through a networking device known as a router. Advanced switches, known as Layer 3 switches, support routing functionality. The switches typically used in homes and offices are Layer 2 switches and don't support routing functionality.

 

Routing

Figure 3: Routing between different subnets

 

How are IP Addresses Assigned?

IP addresses are assigned

  1. Manually, or
  2. Automatically, through the Dynamic Host Configuration Protocol (DHCP) protocol.

IP addresses assigned manually are known as static addresses. Manual IP address assignment is feasible for small networks i.e. networks with a limited number of devices but becomes difficult for networks with hundreds or thousands of devices.

IP addresses assigned through DHCP can change. DHCP-assigned IP addresses are valid for a period of time known as the lease time. The duration of the lease time is configurable.

For the DS system, either a router assigns the IP addresses via DHCP, or the addresses are assigned manually.

 

How Can You Check Connectivity on a Computer Network?

The simplest way to check connectivity between devices on a computer network is through Ping, a software program used to test reachability on an IP network.

The following screenshot shows the Ping result for 8.8.8.8, the IP address for a Google server. This snapshot shows that the computer running the Ping has connectivity with the Google server.

The snapshot also shows the round-trip time, which is around 24 ms. This is because the computer is trying to reach the Google server over the Internet.

On a Local Area Network (LAN), such as the one used for the camera to hub connectivity, this round-trip time is typically 1-2 ms.

 

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Figure 4: Ping response from 8.8.8.8

 

The following screenshot shows the Ping result for 172.16.20.20, an assumed IP address. This screenshot shows that the computer running the Ping does NOT have connectivity with any computer with this IP address.

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Figure 5: Ping response from 172.16.20.20

 

How to Check Camera to Hub Connectivity?

You can check connectivity for each camera from the DS app.

Procedure?

If any of the cameras are not connected to the hub, you have to troubleshoot the issue.

 

How to Check Hub to DS Cloud Connectivity

You can check the Hub connectivity from the DS App.

Procedure?

If the hub does not connect to the DS cloud, you have to troubleshoot the issue.

 

Example Deployments

 

1. The hub and all cameras are connected to the same switch.


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Figure 6: Hub and cameras connected through the same LAN switch

 

2. Hub and cameras are connected to different switches, and the switch-to-switch connectivity is over Cat 5 or Cat 6 cable.


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Figure 7: Hub and cameras connected through multiple LAN switches, with Cat5/6 inter-switch link

 

3. Hub and cameras are connected to different switches, and the switch-to-switch connectivity is over fiber optic cable.

 

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Figure 8: Hub and cameras connected through multiple LAN switches, with fiber optic inter-switch link



Upstream Bandwidth Requirements

The following table shows upstream bandwidth requirements for the PoE system.

 

Table 1: Upstream bandwidth requirements

upstream_bandwidth_requirements

 

Q2. Can the customer upgrade RAM?

Answer:

The amount of RAM required for the hub depends on the number of installed cameras. The following table shows the recommended total RAM for different camera count configurations.

 

Table 2: RAM vs Total Cameras

RAM_vs_cameras

Please also see the following figure.

 

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Figure 9: RAM vs. total cameras

 

Note: ALWAYS discharge any static electricity before touching the RAM. To do this grab the frame or the case of the PC/Hub. This will discharge any static.

 

Q3. Can the customer upgrade the GPU?

Answer:

DS engineers selected the GPU for the hub after numerous technical evaluations. It has been rigorously tested for different system configurations and meets the desired performance expectations.

Using a different GPU can lead to performance and compatibility issues.

Therefore, DS does not recommend changing the GPU for the hub.

 

Q4. What's the best way to troubleshoot when a POE hub shows online and all cameras are offline even after multiple reboots?

Answer:
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Figure 10: DS PoE System Architecture

 

If the hub is online and all cameras are offline, this means that connectivity from the LSC to the hub is ok. Possible reasons for the offline camera issue are

  1. Disabled application layer ports.
  2. Insufficient Internet bandwidth.
  3. Issues with local connectivity for the cameras.
  4. Issues with the hub that prevent cameras from coming online.
  5. The cameras are not onboarded via the DS app.

 

Disabled TCP/UDP Layer Ports

Each computer application e.g. email is assigned a port number. This port number - usually abbreviated to port - is how the computer recognizes which computer application the traffic belongs to.

There are also communication protocols that use Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) that are identified by port numbers.

For PoE cameras to come online certain TCP/UDP ports have to be enabled. Verify that the following ports are enabled on the customer network:

  • Port 443 for the websocket protocol.
  • Port 8883 for the mqtt protocol.

You will need to enable these ports if they are disabled, or rectify the configuration if required. If the network equipment at the customer end is managed by an IT company, the customer will need to call them in to check the configurations.

 

Insufficient Internet Bandwidth or High Packet Loss

 

Verify Internet Bandwidth

The required minimum upload speed depends on the number of cameras at the customer site.

DS recommends 1.5 Mbps upload per camera PLUS a baseline of 5 Mbps. Please see Table 3 for details.

Run an Internet speed test from the customer site to verify the available Internet bandwidth.

If there is insufficient Internet bandwidth, the customer will have to take up the issue with their

ISP.

 

Table 3: Upload requirement vs Number of Cameras

upstream_bandwidth_requirements

Check for Packet Loss

There is always a certain amount of packet loss on IP networks. Packet loss is caused by insufficient bandwidth, faulty cabling, faulty connectors, and other issues with the transmission medium.

The acceptable packet loss varies from application to application. Real-time traffic such as audio and video cannot tolerate high packet loss. Applications such as email and web browsing can tolerate packet loss of 2 to 3%. For video traffic, the packet loss should be as close to zero as possible.

A simple way to check for packet loss is with a Ping test.

If you are onsite, connect a laptop to the same switch and run the Ping test.

 

If you are offsite,

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Figure 11: Camera bandwidth utilization

 

If there is significant packet loss, the customer will have to take up the issue with their ISP.

 

Issues with Local Connectivity for Cameras

Verify local connectivity for the cameras:

  • As shown in Figure X, the router, PoE switch, cameras, and PoE hub should not be changed after initial onboarding. The reason for this is that the router assigns IP addresses to the cameras. If the router is changed or the router configuration is changed, the IP addresses assigned to the cameras can change. This can lead to a loss of connectivity between the hub and the cameras. Verify the IP addresses of the cameras. If the cameras have a different IP address than originally configured, you will need to add the cameras again by using the DS app.
  • All cameras connect to the hub via the PoE switch. Issues with the switch can cause a loss of hub-to-camera connectivity.
    • First verify hub-to-LSC connectivity by running a Ping test. If this test is successful, it means that
      • Hub to switch connectivity is ok.
      • Hub to LSC connectivity is ok.
    • Verify hub-to-camera connectivity by running a Ping test from the hub to each camera. If Ping tests are ok, this means that the local network connectivity is ok, and you need to check the integrity of the hub as explained later.
    • If there is no connectivity between the hub and any of the cameras:
      • Reset the switch once.
      • If resetting the switch does not work, check the switch configuration. If there are issues with the switched, configuration, rectify them.
        • If the customer has supplied the switch, the responsibility for rectifying any issues with the switch lies with the customer.
      • Change the PoE switch and check hub-to-camera connectivity again.

 

Issues with the Hub that Prevent Cameras from Coming Online.

The PoE hub is in a desktop computer tower case, with thumbscrews on the rear sides to remove like opening up a desktop computer.

  • Power off the hub first, and lean over on the side with the power button, USB, and HDMI connection.
  • Open the other side with the thumbscrews and slide that side off to view the components and cables easier.
  • Verify all cables are connected and secure, both hard drive (HDD) cables, to the motherboard and the power supply unit (PSU).
  • Verify the graphics card (GPU) is connected and seated correctly in the motherboard's socket. On-site engineers should contact LSC to confirm about camera errors. LSC against can verify through admin dash once online, indicating this: nvidia nvh264sldec error.
  • Verify the speaker wire is connected to the motherboard. If secured correctly; they should look like the below, pictured:
  • Verify the RAM is installed correctly, with the correct amount installed per camera count, in the slot(s) in the motherboard. NOTE - ALWAYS discharge any static electricity before touching the RAM. Grab the frame or the case of the PC/Hub to discharge static.

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Figure 12: RAM vs. total cameras

 

  • Check that the cooling fan is secured in its place next to the heat sink and that the fan has not come loose, ajar, or disconnected from the motherboard. If secured correctly; they should look like below, pictured:

We can add a flowchart here once the DS engineers review and approve the troubleshooting process.

 

Q5. What is a dangling camera?

Answer:

You can delete camera(s) from the DS app, even though the camera(s) may be connected to the hub over the network.

Sometimes what happens is that after deleting a camera from the app, you are not able to add it back, even though the camera is connected to the hub. A dangling camera is a camera that you can’t add back after deleting it from the app



Q6. Does a dangling camera create subscription issues with the camera count? I.e., Is the customer being billed for another camera that is dangling?

Answer:

When you add a camera through the DS app, the camera gets added to the customer database on the cloud. Each customer gets billed according to the total cameras for that customer in the database.

Even if you delete a camera from the DS app, the customer will continue to get billed for that camera as the camera is still included in the customer database.

Therefore if there are any dangling cameras, the customer will get billed for them.

 

Q7. Can we factory reset a POE camera or a dome camera?

Answer:

DS cameras do not feature a factory reset button.

However, it is possible to reset a camera through the DS app User Interface (UI).

Resetting the cameras remotely through the UI can lead to unexpected problems.

Therefore, to prevent any unforeseen events, DS recommends performing the reset locally i.e. the person performing the reset should be present on site.

The UI login credentials for the camera reset are

User name: deepsentinel

Password: deepS3ntin3l

 

Q8. What kind of switch is recommended: managed or unmanaged switch?

Answer:

The DS PoE system works with managed and unmanaged Ethernet switches.

 

What is an Unmanaged Switch?

An unmanaged switch allows Ethernet devices to communicate with each other and has a fixed configuration. Unmanaged switches are typically used for small networks.

 

What is a Managed Switch?

A managed network switch allows Ethernet devices to communicate with each other and supports features for configuring, managing, and monitoring traffic on a Local Area Network (LAN).

A managed network switch provides more control over how data travels over the network and who can access it. Managed switches cost more than unmanaged switches.

 

VLAN

A Virtual LAN or VLAN is a virtually segregated network. For example, on an 8-port switch, 4 ports can be assigned to the VLAN A and 4 ports can be assigned to VLAN B. The devices on each VLAN will communicate with each other but will not communicate with devices on the other VLAN.

To enable communication between devices on different VLANs you need either a

  1. Separate physical router, or
  2. A switch that supports routing functionality i.e. a Layer 3 switch.

The VLAN feature is supported on managed switches. If the customer is using managed switches with VLANs, then the Hub, cameras, Internet modem etc need to be on the same VLAN, otherwise, the devices will not communicate with each other.

 

Managed or Unmanaged?

The DS system works with either managed or unmanaged switches.

However, it has been observed that managed switches are frequently misconfigured. This leads to problems during system setup and operation.

Therefore, it is expected that the use of unmanaged switches will lead to fewer problems (if any) during system setup and operation.

It is quite likely that some customers will use managed switches. In such cases, the responsibility for switch configuration lies with the customer, and the responsibility for correcting the switch configuration also lies with the customer. If the customer lacks the technical expertise to fix the switch configuration and troubleshoot problems, then the customer can request technical support from the switch vendor.


Q9. How do we perform an audio test for a POE camera?

Answer:

The process for carrying out the audio test is as follows:

  1. Login to the DS app.
  2. Tap on “Settings”.
  3. Tap on “Camera Options”.
  4. Under Audio‚ tap on Siren and Audio Test.


Q10. Is the AI Deterrent feature working on POE cameras?

Answer:

The AI deterrent feature is working for POE cameras.

This feature allows immediate escalation using a pre-recorded voice clip. This way, escalated events do not have to wait for a guard to become available.


Q11. What is the cabling threshold for cat 5 or 6 cables?

Answer:

The maximum recommended length for a Cat-5e or Cat-6 cable is 100 m or 328 ft.

 

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Figure 13: Cat5/Cat6 maximum distance

 

Please also note the following:

  1. The minimum bend radius for Category 6, 5, and 5e cables is four times the cable diameter, or approximately 1 inch. When cabling is bent beyond this specified radius, it can cause transmission failures.
  2. For best performance keep the Ethernet cables away from AC wiring.

If required, DS provides a 16-port TP-Link PoE switch.

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Figure 14: DS Ethernet switch

 

Ports numbered 1 to 8 (shaded red on the front panel) support an extended range function. If the customer installation requires cameras that are over 100 m (328 ft) away from the switch, then you can enable “Extend Mode” and connect these cameras to port number 1 to 8. With “Extend Mode” on, the switch can supply devices up to 250 m away. However please note that the use of the “Extend Mode” feature is not recommended if an NVR is used on the network and the camera video resolution is set to 4K.

 

Q12.Is there a way to adjust the camera FOV for POE cameras, for example, tilt it down?

Answer:

What is Field of View (FOV)?

The Field of View of a camera is the width of the scene that a camera detects on its sensor. It is determined by the focal length of the lens in relation to the sensor size. The FOV is therefore fixed by the lens. The only way to change the FOV is to change the lens or use a different camera.

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Figure 15: Horizontal FOV vs Vertical FOV

When discussing cameras, we usually refer to the horizontal FOV. Typical values for the horizontal FOV are 60°, 90°, and 120°.

Even though it is not possible to change the FOV for DS cameras, you can change the viewing angle. You can only change t