What is one of the main functions of IPsec?

One of the main functions of IPsec is to protect data transmission between hosts. IPsec operates at the network layer and provides authentication, integrity, and encryption for the data being transmitted over an IP network. This is crucial for ensuring that sensitive information remains confidential and secure from eavesdropping or tampering during transmission.

When IPsec is implemented, it establishes a secure communication channel between devices, which helps in safeguarding the data packets as they travel across potentially insecure networks. By using protocols like Authentication Header (AH) and Encapsulating Security Payload (ESP), IPsec ensures that only authorized devices can communicate, and that the data remains intact and private.

In contrast, the other choices involve aspects not primarily associated with IPsec's core function. For instance, IPsec does not create or signify data loss, nor does it enhance network speed, as its focus is on security rather than performance optimization. Additionally, establishing wireless connections pertains more to different networking technologies rather than to the specific function of IPsec in securing data transmission.