This article applies to organisations with a 'Hybrid' setup (both On-Premise Appliance and Cloud), as well as On-Premise only and Cloud only setups.
Smoothwall sorts websites and web content into different Categories. These Categories work with the policies you set to determine whether to allow or block access.
Tip
In addition to filtering, you can use Content Modification to restrict the type of content shown on allowed websites, such as Search Engines.
How Smoothwall applies filtering
Smoothwall uses several parts of a web request to categorise and filter content.
URL and domain filtering
Smoothwall reviews each URL and domain request. It blocks access if a Web Filter Policy is in place and at least one of the following applies:
- The URL or domain is in our list of categorised domains, Custom Blocked Content or your custom domains list.
- The URL or domain contains a word, term or phrase that indicates a specific type of content.
Note
Smoothwall blocks access to some websites under all circumstances, even if you’ve explicitly allowed them in a Web Filter Policy. These include websites known for containing extreme violence or CSAM.
Real-time content filtering
Important
When applying filtering from On-Premise Appliance, you must use HTTPS Inspection to allow real-time content filtering.
Smoothwall blocks potentially harmful websites even when the domain or URL looks harmless.
- We score each part of the content, context and construction of the page.
- Smoothwall analyses the HTML and the webpage content to assign a Category.
Note
Real-time content filtering works in addition to other filtering methods. For example, a Facebook gardening group is categorised as Social Media through URL and domain filtering and Gardening through real-time content filtering.
- If the page’s score passes the threshold, Smoothwall blocks access.
- Users can see the Reason for the block on the Block page.
Search term filtering
When users enter words, terms or phrases into a search engine, Smoothwall checks them against our list of blocked terms and your list of custom Search terms. If a term matches, Smoothwall stops the search engine from showing results, preventing access to harmful links.
Categorisation hierarchy
The hierarchy consists of these items, from most encompassing to least.
For example, all domains for Vimeo make up the Vimeo Signature. This is part of the Streaming Media Built-in Category, which is part of the Arts and Entertainment Theme. You can see Signatures, Built-in Categories and Themes listed in Blocklist Categories.
| Name | Description | Used in policies and reporting | Customisable |
| Themes | Group Categories and Signatures into broad topics. Note These are different to Safeguarding Themes. |
No | No |
| Category Groups | Combine Built-in Categories, Custom Categories and Signatures to save time when creating policies. For example, you’ll have the Core Blocked Content Category Group as part of your default Web Filter Policies. |
Yes | Yes |
| Categories | Group related Signatures into Built-in or Custom Categories to simplify filtering. For example, block the Streaming Media Category to block YouTube, Vimeo, DailyMotion etc. |
Yes | Yes |
| Signatures | Target a specific service or website, such as YouTube. Like Categories, these can be Built-in or Custom. | Yes | Yes |
Suggest a change to categorisation
Our Digital Safety Team constantly reviews websites and decides whether to block them. As Smoothwall products are used to protect vulnerable users, including children, we prioritise safety and tend to over-block, which may occasionally block some safe content.
We are continuously improving our filtering. If we miss a website or miscategorise it:
- Use the Blocklist Feedback Form to let us know.
- We’ll either update our Built-in Categories or advise you to create a Custom Category to use in a Web Filter Policy.
We install updates to our Built-in Categories overnight through Blocklist updates.