VPNs for Video Surveillance Guide
Remote access in surveillance networks is a key cyber security and usability issue. With cyber attacks rising, how can users ensure their systems are secure without losing access from outside the network?
Virtual private networks (VPNs) have historically been used in complex / large systems to secure data but can also be used in smaller sites with relatively inexpensive. To better demonstrate this we purchased two Dell SonicWall SOHO routers and configured them to simulate a site to site VPN.
Inside, we look at VPN usage in video surveillance, including the following topics:
- What is a VPN?
- VPN protocols
- VPN topologies
- VPN price considerations
- Benefits and drawbacks
- Site to site VPN configuration
- Remote access VPN configuration
- Mobile device usage
- Recommendations for VPN use
Virtual Private Networks
A VPN is a private network that creates a secure tunnel over the internet to connect two or more endpoints. These endpoints can be a VPN appliance, a workstation, or a mobile device. Encryption creates a secure connection from one endpoint to the other keeping data private, even while transmitted over the internet. For example, looking at a Wireshark trace of a secure tunnel, once the TLS connection is set up, only "Application Data" is shown, as packet contents are encrypted.
There are several VPN protocol options, which mainly vary in level of encryption and device compatibility. These include:
In this tutorial, our VPN setup used IKEv2 over IPSEC on SonicWALL devices.
There are two commonly used VPN topologies, which have different use cases:
- Site to site: A site to site VPN requires an appliance at both locations, which essentially routes the two remote networks together into a single virtual network. In security, this may be used to connect two facilities' camera LANs together so they may be managed and viewed as one, from either location.
- Remote access: In a remote access VPN there is one VPN appliance (also known as a concentrator) and a workstation which connects via client software. This type of VPN may be used to connect remote users to a security network for viewing, or for configuration/troubleshooting tasks for integrators.
We discuss these topologies in more detail below.
VPNs are most often run on dedicated hardware, typically included on a router or firewall. Pricing for hardware VPN varies depending on capabilities (typically number of VPN tunnels) and throughput handling. Some may be found for <$100 USD online, while large capacity VPN concentrators sell for more than $10,000.
In addition to hardware VPN appliances, users may install software to turn a server/PC into a VPN concentrator. The most popular option for this is OpenVPN, which is priced at $15/year per client.
There are three key benefits to VPNs:
- Security: Because all traffic between VPN endpoints is encrypted and surveillance/security devices are not exposed directly to the internet, VPNs provide improved cyber security compared to port forwarding/DDNS. Note that cloud services such as Hik-Connect, Nest, etc., also encrypt this traffic.
- Reliability: Because they use dedicated hardware, VPNs are typically more reliable than using cloud services or DDNS, which are outside of users' control.
- Accountability: Unlike other remote access methods, VPNs keep full log information, allowing users to determine who access which device at a given time, etc., for better auditing.
However, there are two drawbacks which have kept VPNs from being more commonly used:
- Cost: VPN hardware adds cost to a project, where manufacturer cloud services and port forwarding/UPnP are generally free. Dynamic DNS is most often not free, typically a few dollars per month to $100+/year.
- Complexity: VPN setup requires IT expertise which many/most surveillance installers do not possess. Even among those in the IT field, many have never set up VPN policies.
Site to Site VPN Example
As an example of a site to site VPN, the diagram below illustrates a headquarters location with a VMS server and viewing station, along with a satellite office with multiple cameras and a viewing station. Using a site to site VPN, the entire security network functions as one.
To better demonstrate this we purchased two SonicWall SOHO routers and configured them to simulate a site to site VPN.
In this section we outline the steps taken to configure our routers for site to site VPN use. The exact steps required by specific manufacturers vary, but basically VPN creation is a three step process:
Create VPN policy → Define networks → Select networks to connect
In this step, we select the type of VPN (site to site), protocol used, and give it a name and shared secret (similar to a password, used by both devices to connect).
Define Local and Remote Networks
Next, we must define networks for both the local and remote site in order to create routing rules. There are two key notes in this step:
- This must be performed on both devices. In other words, in our example, we must define the satellite office network (192.168.2.x) on not only the HQ router, but the satellite as well. The same must be done for the HQ network (192.168.1.x) on both devices.
- These networks must not use the same subnet in order to route properly. This is why we used 192.168.1.x for the HQ and 192.168.2.x for satellite.
Note that counterintuitively, both these networks are assigned to the "LAN" zone in this example. Despite one logically being the "WAN", SonicWALL reserves that terminology for other uses, so both are LAN.
Select Networks To Connect
With them defined, we can now select the two networks to be connected via the VPN. On the HQ appliance, we select the HQ network defined above as "local", and choose "Satellite Office" as the destination network. On the Satellite Office appliance, we would do the reverse.
Enable Policy To Connect
Once we configure both VPN appliances with the above, we can enable the policy to connect the two sites. In the video below, we show that the sites are unable to communicate with each other until the VPN tunnel is established. When the VPN is active devices start responding to ping requests and the camera can be remotely viewed / administered.
Remote Access VPN
In many situations we do not require an entire site to connect to our network, and often our users connect from networks that we do not control. We can provide individual users with VPN access. The configuration starts the same as a point to point solution, create VPN policy. After that we walk through creating a VPN user, and configuring the client software.
The configuration starts with creating a VPN policy on the appliance located at the site that requires access. This simply requires the connection type, a name, and shared secret. Note that this shared secret is similar to, but separate from, individual user passwords.
After the policy is built on the VPN appliance, we create user accounts. These credentials are used on client devices when connecting to the VPN.
Finally, users are assigned one or more network which they may access via the VPN. These networks are defined above in the Define Local/Remote Networks section.
Accessing VPN Via Client
With the above user created, we may now use the software client to access the VPN, shown below:
Remote VPN Example: VMS Client to Server
The animation below demonstrates a common use case for remote VPN, connecting a client machine to remote server(s). In the example below, servers are unreachable when the VPN is disconnected, but come online once the connection is established, with live video loading in only a few seconds.
Remote VPN Example: Mobile Device to Server
Many/most VPNs may be used on mobile devices in addition to hardware/software clients. For example, the image below shows Exacq Mobile running on an iPhone, connected to a remote server via the SonicWALL Mobile Connect app. VPN status is indicated in the top bar, next to the mobile carrier status.
Given the increase in cyber attacks (both severity and frequency) along with the falling costs of VPN hardware, we expect VPN usage to become more common in 2017 and beyond, as it provides better security and accountability than other remote access methods. These issues are likely to only increase in importance as cyber security issues continue to increase.