Cisco ASA supports two major WebVPN modes: Clientless WebVPN and Anyconnect WebVPN.
Let’s see the differences between the two WebVPN modes and I’m sure you will understand why the AnyConnect mode is much better in my opinion.
Clientless WebVPN does not require any VPN client to be installed on user’s computer. It uses a normal web browser. By pointing the browser to https://[outside address of ASA] the user authenticates with the firewall and gets access to a Web Portal. Through this Web Portal, the user can then access a limited number of internal applications. Specifically, only internal Web applications (HTTP, HTTPs), email servers (POP3, SMTP, IMAP), Windows file shares and a small number of TCP legacy applications (e.g Telnet) can be accessed. That is, there is no full network connectivity with Clientless WebVPN.
AnyConnect WebVPN, on the other hand, provides FULL network connectivity to the remote user. The ASA firewall, working as AnyConnect WebVPN server, assigns an IP address to the remote user and attaches the user to the network. Thus, all IP protocols and applications function across the SSL VPN tunnel without any problems. For example, a remote user, after successfully authenticated with AnyConnect VPN, can open a Remote Desktop connection and access a Windows Terminal Server inside the central network. Although a special Java-based client is required to be installed on the user’s desktop, this client can be supplied dynamically to the user from the ASA. The user can connect with a browser to the ASA firewall and download the Java client on demand. The Java client can remain installed or even get removed from the user’s desktop when disconnected from the ASA appliance. This Java client is small in size (around 3MB) and is stored on the ASA flash memory.