URL Blockedlisting

Revision History

Note

Revision history details are not provided for features introduced before release 21.24.


Revision Details	Release
First introduced	Pre 21.24

Feature Description

The URL blockedlisting feature regulates the subscribers access to view or download content from websites whose URL or URI has been blockedlisted. It uses a database that records a list of URLs that indicates if the detected URL is categorized to be blocked or not.

How it Works

To enable the URL blockedlisting feature on User Plane (UP), URL blockedlisting database should be present with a name “optblk.bin” under flash, or SFTP or under its sub-directory. This database directory path needs to be configured on user-plane, after user-plane services are brought up.

HTTP Analyzer must be enabled for URL blockedlisting. The HTTP analyzer extracts URL information from the incoming HTTP request data packet. Extracted URL content is compared with the URL Blockedlisting database. Once the incoming HTTP data packet’s URL matches with the database URL entry, that URL is treated as blockedlisted URL and one of the following actions takes place on that HTTP packet.

Termination of flow
Packet is discarded

The URL blockedlisting configurations must be configured on Control Plane (CP), Rulebase configuration under Active Charging Service. Additionally, two URL blockedlisting methods – Exact and Generic, are supported at Active Charging Service-level configuration, on CP. These CLI configurations are pushed to UP through PFD mechanism, during Sx association procedure, to the CP.

Important

Blockedlisting database(s) are provided by – IWF (Internet Watch Foundation) and NCMEC (National Center for Missing and Exploited Children). The ASR5500, CUPS UP always receives the blockedlisting DB in Optimized Format (optimized blockedlisting DB format).

URL Blockedlisting Database Upgrade

URL database upgrade is supported in 2 ways:

Timer-based upgrade or Auto upgrade
CLI-based upgrade or Manual upgrade

Timer-based or Auto-upgrade

After the database is loaded on the chassis for the first time, a timer, for a duration of 5 minutes, is started. This process is started to auto upgrade the database.

If at the expiry of the timer, a valid database with higher version is available at the directory path, then database upgrade procedure is initiated, and a newer version of the database is loaded on the UP chassis.

To upgrade a URL blockedlisting database, a higher version of valid URL Blockedlisting database with name “optblk_f.bin” should be present at same directory as that of current database “optblk.bin”.

After the database is upgraded successfully, the earlier “optblk.bin” file gets renamed as “optblk_0.bin” and “optblk_f.bin” file gets renamed as “optblk.bin”. Here, “optblk_0.bin” file is treated as a backup file of older database.

If one more upgrade is performed, then “optblk_0.bin” file will be renamed as “optblk_1.bin” file and current “optblk.bin” will get renamed as “optblk_0.bin”, and so on.

The number of backup files to be stored in the database can be configured using the max-versions CLI on UP.

CLI-based or Manual Upgrade

In this upgrade method, the CLI command - upgrade url-blacklisting database , upgrades the current database to a newer version.

Limitations

In this release, session recovery and user-plane redundancy support is not fully qualified.

Configuring URL Blockedlisting

Loading URL Blockedlisting Database on UP

Use the following configuration to load URL blockedlisting database on UP.

In releases prior to StarOS 21.26:

configure 
   url-blacklisting database directory path database_directory_path 
   url-blacklisting database max-versions max_version_value 
   end

From StarOS 21.26 and later releases:

configure 
   url-blockedlisting database directory path database_directory_path 
   url-blockedlisting database max-versions max_version_value 
   end

NOTES:

database directory path: Configures the database directory path.

The database_directory_path is a string of size 1 to 255.
max-versions: Configures the maximum database upgrade versions.

The max_version_value is an integer from 0 to 3.

Configuration to Enable URL Blockedlisting

Use the following configuration to enable URL blockedlisting feature on Control Plane.

In releases prior to CUPS 21.26:

configure 
   require active-chargingservice_name 
      url-blacklisting match-method [ exact | generic ] 
      rulebase rulebase_name 
         url-blacklisting action [ discard | terminate-flow ] 
         end

From CUPS 21.26 and later releases:

configure 
   require active-chargingservice_name 
      url-blockedlisting match-method [ exact | generic ] 
      rulebase rulebase_name 
         url-blockedlisting action [ discard | terminate-flow ] 
         end

NOTES:

match-method [ exact | generic ] : Specifies the match method used for URL blockedlisting.

exact : URL Blockedlisting perform an exact-match of URL.

generic : URL Blockedlisting perform generic-match of URL.
url-blockedlisting action [ discard | terminate-flow ]

discard : Discards the HTTP packet received.

terminate-flow : Terminates the flow of the HTTP packet received.

URL Blockedlisting Database Upgrade

Use the following command to upgrade the URL Blockedlisting Database.

In releases prior to CUPS 21.26:

upgrade url-blacklisting database

From CUPS 21.26 and later releases:

upgrade url-blockedlisting database

Note

This CLI is used for manual upgrade of URL Blockedlisting database. File optblk_f.bin must be present in order to upgrade URL Blockedlisting database.

Monitoring and Troubleshooting

This section provides information regarding the CLI command available in support of monitoring and troubleshooting the feature.

Show Command(s) and/or Outputs

This section provides information regarding show commands and/or their outputs in support of this feature.