It gives the following advantages :-

• Performance
• Network Layer security
• Scalability
• Versatile
• Universal acceptance
• Application independance

Here is a list of IP sec disadvantages:-

• Performace
• Security
• Complexity
• Firewall Restriction
• Management

The advantages are as follows :--

• Interoperability: It supports different vendors softwares and applications.
• Management: SSL makes deployment and management and administration tasks simple and effective. No need to install additional client softwares.
• Cost: Its very cheap and no special licenses are required.
• Granular structure : It provides finely detailed client access policies based on user identity and profile.
• Firewall and NAT operation : SSL uses TCP port 443 (HTTPS), which is open on most networks, allowing SSL VPNs to operate without extra administrative overhead.
• Security :By only allowing access to certain applications, security mitigation is increased, and the threat of attack is minimized
• Application layer functionality: SSL eliminates IP-based address management problems by operating at the transport layer and provides services to the upper layers.

Serial Line Internet Protocol (SLIP) is a very simplistic, nonstandard protocol used to frame and transmit IP datagrams over serial connections. Due to its inflexible design, SLIP does not provide additional features such as encryption, authentication, or error detection .

PAP does not use any type of encryption to send usernames and passwords over the link. All authentication data is sent in clear text over the wan link, which is huge security risk.

PAP is extremely vulnarable to various forms of malicious attack, such as password guessing or other brute force attacks.

The PAP remote client controls the amount of authentication attempts to the authentication server or other brute force attacks. This means an attack could continure indefinitely against a PPP authentication server.