ns-3.33 was released on January 9, 2021. ns-3.33 includes the following new features:

• A model for TCP CUBIC congestion control has been added. TCP handling of ECN has also been aligned with Linux behavior.
• New error models for Wi-Fi, based on link simulation results, have been added and made the default. LDPC FEC encoding is also now supported in addition to the default BCC encoding.
• A new Length class has been added to represent lengths (distances) with an explicit unit.
• A channel condition model for propagation impairments due to vehicular scenarios has been added.
• Node positions can now be added from a csv file with the new CsvReader class.
• Wifi 802.11ax PHY layer models for High Efficiency Multi Users (HE MU) access, including High Efficiency Resource Units (HE RU) and PCAP support, have been added.
• Added option to configure the Wi-Fi OFDM transmit spectral mask.
• LR-WPAN models now support handling differences between RFC4944- and RFC6282-style IPv6 address expansion.
• The MPI distributed simulation support now allows the user to supply an MPI_Communicator, enabling optional partitioning of the MPI processes.

The release also includes numerous bug fixes and small improvements, listed in the RELEASE_NOTES.

Download: The ns-3.33 release download is available from this link. This download is a source archive that contains some additional tools (bake, netanim, pybindgen) in addition to the ns-3.33 source. The ns-3 source code by itself can also be checked out of our Git repository by referencing the tag 'ns-3.33'.

Documentation: The documentation is available in several formats from this link.

• What has changed since ns-3.32? Consult the changes and RELEASE_NOTES pages for ns-3.33.
• A patch to upgrade from ns-3.32 to ns-3.33 can be found here
• Errata containing any late-breaking information about the release can be found here